The generation of and research on human neural organoids, transplants, and chimeras are subject to a wide range of oversight mechanisms regarding the use of human tissues and stem cells, as well as the use and welfare of nonhuman animals.1 In the United States, some of this oversight is mandated by federal law, although research may also be subject to state laws and, when it involves collaborating internationally, to regulations in other countries. These legal requirements are often implemented by committees at individual research institutions. There are also de facto limits on research based on what the government or private funders will or will not fund. This collection of laws and regulations is supplemented by nonbinding consensus studies by scientific academies; professional society guidelines; and conference reports by the scientific, bioethics, and advocacy communities. Each of these oversight mechanisms was established to address a specific perceived need within the research enterprise (e.g., protection of human subjects or animal welfare). In contrast, there are few mechanisms for holistic evaluations of new fields of research. This chapter summarizes this patchwork of oversight, including frameworks in other countries. It ends with a review of suggestions that have been made for improving oversight in the future.
A particular challenge to government regulation and voluntary guidelines on research involving human neural organoids, transplants, and chimeras is the broad range of strongly held, and often inconsistent, views in the United States and internationally. Some views are based on religious commitments to different faith traditions, while others are based on secular arguments. Religious commit-
1 Additional rules and guidelines may apply if the research involves human embryos, transgenic animals, pathogens or toxins, certain drugs, or other categories of research.
ments and beliefs are a core source of personal morality and inspiration for many. However, because the United States is a pluralist society, no specific religious tradition may determine public policy. On the other hand, the U.S. National Bioethics Advisory Commission states in its report on cloning of human beings, another deeply contested issue: “Although in a pluralistic society particular religious views cannot be determinative for public policy decisions that bind everyone, policy makers should understand and show respect for diverse moral ideas.”2 Later in this report, this committee articulates the value of ongoing forums for discussion of controversial issues in biotechnology among persons representing different perspectives.
Important protections for research participants are provided by the Federal Policy for the Protection of Human Subjects,3 with oversight by institutional review boards (IRBs) at the respective research institutions. This policy regulates research funded by 18 federal departments and agencies, including the National Institutes of Health (NIH). Part A of this federal policy, known as the Common Rule, was last updated in 2017.4 Protections mandated by the Common Rule apply when research entails an intervention in or interaction with a living individual or uses identifiable information or biospecimens. Thus, work with tissues and cells from the deceased is not subject to the Common Rule, although other rules (e.g., special funding or review requirements related to embryonic stem cell lines) may apply. Also not subject to the Common Rule is research on existing tissue and cells (for example, from a bank or other collection) for which the living donor’s identity is no longer readily ascertainable.
The Common Rule does not apply to all human subjects research done in the United States—research that is done without funding from one of the signatory agencies and that will not be submitted to the Food and Drug Administration (FDA), for example, may not be within its scope, but it is the broadest regulation of such research in the United States and may often provide a framework for oversight of even noncovered work. This is particularly true of major research universities, which may follow the substantive and procedural aspects of the Common Rule for all human subjects research regardless of funding source. The FDA
2 U.S. National Bioethics Advisory Commission, “Cloning Human Beings, Volume 1: Report and Recommendations of the National Bioethics Advisory Commission,” 1997, p. 7.
3 Statutory authority for the regulations for the protection of human subjects derives from the National Research Act of 1974.
4 82 Fed. Reg. 12 (January 19, 2017).
has adopted regulations close to but not exactly following the Common Rule on some aspects of consent and consent waivers.5
Researchers usually employ stem cells to generate the neural and glial cells used to create human neural organoids, transplants, and chimeras. These stem cells include induced pluripotent stem cells (iPSCs), derived from somatic cells (usually skin or blood cells) of adult donors; embryonic stem cells (ESCs); and, less commonly, fetal cells.6 Because ESCs raise more ethical, legal, and funding concerns than iPSCs (and entail additional oversight and funding restrictions), researchers often use iPSCs if feasible. Table 4-1 summarizes regulations and guidance on the use of human stem cells for this research.
The Common Rule is heavily influenced by the 1979 Belmont Report of the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research,7 as well as, in part, by the Helsinki Declaration, which lays out ethical principles for medical research involving human subjects.8 Although there are a wide range of policies throughout the world (HHS, 2020), protections for human subjects are broadly recognized.
The Common Rule generally requires IRB approval of human subjects research and contains specific requirements for IRB membership, function, operations, and review of research. The IRB must determine that the research protocol meets specified criteria, including reasonable risks in relation to anticipated benefits, equitable subject selection, protection of confidentiality of the research participants, adequate informed consent, and participant safety. The focus for IRBs in overseeing research on human neural organoids and transplants (and potential future research involving chimeras) is on obtaining informed consent for donation of human biospecimens; protecting the privacy interests of living, identifiable donors; and, if donors placed special limits on the use of their cells, ensuring research use consistent with those limits.
Transplantation of human neural cells or organoids into humans would be subject to both additional oversight by IRBs (because the human transplant recipient would also be a human subject) and additional review by the FDA pursuant to its authorities that cover granting permission to begin clinical trials or marketing of human cell, tissue, and cellular- and tissue-based products.9
At many institutions, research using human ESCs or iPSCs is subject to additional oversight by Embryonic Stem Cell Research Oversight (ESCRO) commit-
5 If or when organoids or human cells are transplanted into animals that are used for therapeutic purposes, any research that supports a commercial product application to the FDA will also need to comply with FDA regulations for protection of human subjects (21 C.F.R. 50).
6 Research involving fetal tissues is subject to a wide range of rules and oversight, which were summarized for the committee by Valerie Bonham and Mark Barnes, Ropes & Gray LLP, at its November 13, 2020, virtual meeting, are not discussed in more detail in this chapter.
9 21 C.F.R. § 1271.
|Type of Research||Common Rule (federal regulations for research funded by U.S. government)||National Institutes of Health (NIH) Guidelines for Human Stem Cell Research (funding requirement)||Nonbinding Guidance|
|Research using human induced pluripotent stem cells (iPSCs) from deidentified donor cells (e.g., from a biobank)||Exempt from institutional review boards (IRB) review if cells are appropriately deidentified||N/A||
Exempt from Embryonic Stem Cell Research Oversight (ESCRO) committee review (NRC and IOM, 2010)
Exempt from Embryonic Research Oversight (EMRO) review (ISSCR, 2016)
|Research using human iPSCs from identifiable donor cells||IRB oversight to determine appropriate informed consent (including broad consent or waiver of consent), confidentiality, etc.||N/A||
IRB review should determine that informed consent includes the possibility of use in animals
(NRC and IOM, 2010, ISSCR, 2016)
|Research using deidentified human embryonic stem cells (ESCs) (e.g., from a biobank)||Exempt from IRB review if cells are appropriately deidentified||Specific requirements for origin of cells, including consent from donors of embryos and gametes||
ESCRO should determine that cells were “acceptably derived” (NRC and IOM, 2010) No specialized EMRO review
|Research using identifiable human ESCs||IRB oversight to determine appropriate informed consent, confidentiality, etc.||Specific requirements for origin of cells, including consent from donors of embryos and gametes||
Review by ESCRO (NRC and IOM, 2010)
Review by EMRO (ISSCR, 2016)
NOTE: Additional oversight is required if the use of human stem cells includes transplantation into a nonhuman animal (see Table 4-2).
tees or Stem Cell Research Oversight (SCRO) committees, which are generally described in the National Academies Guidelines for Human Embryonic Stem Cell Research, first published in 2005 and most recently updated in 2010 (NRC and IOM, 2010). These committees ensure that the research follows federal, state, and funding agency guidelines and has undergone appropriate scientific and ethical review. The National Academies guidelines provide recommendations on the membership of ESCROs, which should include individuals with expertise
in developmental biology, stem cell research, molecular biology, assisted reproduction, and ethical and legal issues in human embryonic stem cell research. A nonscientist member of the public not affiliated with the institution should also be included. The International Society for Stem Cell Research (ISSCR) Guidelines for Stem Cell Research and Clinical Translation (2016; update expected in 2021) recommend a similar type of oversight (ISSCR, 2016).
Although the guidelines of the National Academies and the ISSCR are nonbinding, both are widely followed by institutions that conduct this type of research. Some states, including California10 and New York (Shah, 2013), have made oversight by an ESCRO or SCRO committee mandatory for research funded by the state. ESCROs, SCROs, or Embryonic Research Oversight (EMRO) committees could consider a wide range of ethical issues related to research involving human stem cells, including the possibility of altered capacities in chimeric animals or the development of consciousness in organoids, but there is very little information about how these committees function at different institutions.
In general, guidance related to the disposal of human tissue from live-born human beings that is used in research is designed to protect researchers, clinicians, and others from harms that might arise from those tissues, such as infectious diseases or environmental contamination. Some organizations providing tissue may specify requirements for disposal or return of unused material through material transfer agreements, but this is negotiated between the parties. The Common Rule, National Academies guidelines, and ISSCR guidelines do not address disposal, indicating that such issues have not generally been seen as raising ethical concerns. In practice, in research laboratories, disposal of human neural tissues does not differ from disposal of other biomaterials.
Ethical issues surrounding informed consent are discussed in Chapter 3; the oversight mechanisms described here were established to address many of those concerns, although it is important to remember that the legal regulation around informed consent may not be coextensive with those ethical issues. Informed consent is a key requirement of the Common Rule, which requires investigators to provide prospective research subjects the information necessary for them to make an informed and voluntary decision about whether to participate in the research.11 The requirements for consent from participants for an initial donation of tissues (e.g., skin cells that will be used to generate iPSCs) differ from those for use of existing biospecimens in subsequent studies.
10 California Institute of Regenerative Medicine Regulations § 10060 (SCRO Committee Membership and Function) and § 10070 (SCRO Committee Review and Notification).
11 45 C.F.R. § 46.116.
Collection of New Biospecimens for Research
New biospecimens may be collected for research in two ways. First, if biospecimens are obtained specifically for research, informed consent is required from the donor. Ethically, researchers must disclose information that reasonable people would want to know about how their tissues will be used. Many might argue that this information should include any intention at the time of collection to use the tissues to generate a neural organoid or to transplant derived materials into a nonhuman animal. However, this is not required in current regulations, and IRBs can differ in how they interpret what a “reasonable” person might want to know before donating. The regulations require that participants be informed that deidentified biospecimens and information might be used for future research or shared with other investigators without additional consent. When applicable, research participants must be informed of possible commercial profit from the research (and whether they will share in this profit), whether research activities will or might include whole genetic sequencing, and whether clinically relevant research results will be returned to participants. As of 2015, NIH funding policy for genomic studies requires “explicit consent for participants’ genomic and phenotypic data (which may include some clinical information) to be used for future research purposes and to be shared broadly through data repositories” (NIH, 2019).
A second approach to obtaining new biospecimens for research is to derive them from tissue or cells considered surgical or medical waste. If these specimens are collected and used in a manner such that the identity of the people from whom they were derived cannot be readily ascertained by the researchers, the activity is not considered human subjects research, and consent is not required. If identifying links are retained, consent is necessary as described above.
Obtaining consent to use biospecimens and data for future research is challenging because it is impossible to anticipate or describe all future research projects. The 2017 revisions to the Common Rule allow biospecimens or information to be used in future research or shared with other researchers—for example, through a biobank—without additional consent.
The most commonly used approach to obtaining consent for future research and sharing of biospecimens and information with other researchers is deidentification: donors are told that future research and sharing might be carried out in such a way that “the identity of the human subjects cannot readily be ascertained directly or through identifiers linked to the subjects, the investigator does not contact the subjects, and the investigator will not re-identify subjects.”12 In everyday discussions, the literature, and this report, such specimens are called “deidentified,” and the persons who provide the materials for research are called “donors.” With such disclosure, future research and sharing are permitted without additional consent.
An alternative to obtaining consent for future research and sharing of identifiable specimens and information is broad consent. The research subject must be
12 45 C.F.R. § 46.104 (d)(4)(ii).
given a general description of the types of research that may be conducted, in sufficient detail that a “reasonable person would expect that the broad consent would permit the types of research conducted.”13 For broad consent, donors must be told that they will not be informed of the details of such specific research studies and that they might have chosen not to consent to some of those specific research studies.14
Research with Existing Biospecimens
As discussed above, secondary research with deidentified existing biospecimens and data is not considered human subjects research, and additional consent or full IRB review is not required. This policy lies at the heart of some of the ethical concerns with tissue- and cell-based research. While a person who is unidentifiable may have no privacy interests to protect, that person may nonetheless be unhappy at having unwittingly contributed to a form or research that he or she views as immoral or emotionally disturbing. This is one example in which the regulatory protections do not extend as far as what some would argue are legitimate ethical concerns, although extending the regulations to such situations would arguably undermine other values, such as the interest in health-promoting scientific research.
To protect the identity of the donors, a biobank can share specimens together with associated phenotypic information after replacing personal identifiers with a code number that is not shared with the secondary researchers. In one approach to deidentification, the biobank destroys the links between the code numbers and overt identifiers. In another approach, the biobank retains the links but adopts a policy of never sharing them with secondary researchers. Of note, deidentifying specimens and data precludes recontacting donors—for example, to inform them of clinically actionable research findings. Providing deidentified specimens and data simplifies the oversight process for secondary researchers. However, there are growing concerns, discussed below, about the ability of new technologies to “reidentify” donors of nominally “deidentified” tissue.
In addition to situations that involve carrying out future research and sharing deidentified specimens, additional consent and full IRB review are not required in two other cases. First, as discussed previously, if biospecimens and information remain identifiable but were collected with broad consent for future research, the additional research may proceed without additional consent if the IRB ascertains that the proposed new research falls within the terms of original donation of the biospecimens. Second, for other research using existing identified biospecimens or information, secondary researchers may request a waiver or alteration of informed consent under certain circumstances.
13 45 C.F.R. § 46.116(d).
14 45 C.F.R. § 46.116(d).
Research involving human neural cell transplants into nonhuman animals or chimeras is subject to the rules and regulations related to the use of animals in research, including oversight by institutional animal care and use committees (IACUCs), which are mandated at the federal level. The Animal Welfare Act (AWA) of 1966 is overseen by the U.S. Department of Agriculture’s (USDA’s) Animal and Plant Health Inspection Service and applies to all research on warmblooded animals (excluding birds, rats, and mice raised for the purpose of laboratory use), regardless of the source of funding.15 In addition, the Public Health Service Policy on Humane Care and Use of Laboratory Animals (PHS Policy), last updated in 2015, covers all live vertebrate animals involved in activities funded by agencies within the PHS, including NIH, the FDA, and the Centers for Disease Control and Prevention (CDC).16 The PHS Policy incorporates the 1985 U.S. Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research and Training (U.S. Government Principles) (NIH, 2018), which apply to all federal agencies. The PHS Policy and the U.S. Government Principles help define best practices for animal use and care and are widely followed even by institutions that do not receive federal funding. The PHS Policy has also adopted guidance developed by the National Academies (Guide for the Care and Use of Laboratory Animals, last updated in 2011 [NRC, 2011]) and the American Veterinary Medical Association (Guidelines on Euthanasia of Animals, last updated in 2020 [AVMA, 2020]). IACUCs ensure compliance with this range of government laws, policies, and guidance.
Federal regulations require that research protocols describe the research, approaches used to reduce animal numbers, justification for the use of animals, information on alleviation of pain and distress, methods of euthanasia, an understanding of the scientific literature, and plans for appropriate veterinary care. The committee notes that the requirement to justify the use of animals in terms of prospective benefit to human health in the case of neural cell transplant and chimera research goes conceptually beyond the Three R’s framework (reduce, refine, and replace) described in Chapter 3. These protocols must be reviewed and approved by an IACUC, with periodic review of ongoing research. According to the PHS Policy, IACUCs must have a minimum of five members, including one doctor of veterinary medicine with training or experience in laboratory animal science and medicine who has direct or delegated program authority and responsibilities for activities involving the animals at the institution, one practicing scientist experienced in research involving animals, one member whose primary concerns are in a nonscientific area (e.g., an ethicist, lawyer, or member of the clergy), and one individual who is not affiliated with the institution in any way other than as
15 7 U.S.C. §§ 2131–2159 (Pub. L. 89-544), with implementing regulations: 9 C.F.R., § 1(A).
16 See https://olaw.nih.gov/policies-laws/phs-policy.htm. Statutory authority derives from the Health Research Extension Act of 1985, 42 U.S.C. Ch. 6A(II)(A), (III, § 283[e]), and (III, Part H, §289d), Pub. L. 99-158 (11/20/85).
a member of the IACUC and has no immediate family members affiliated with the institution.
Under the PHS Policy and U.S. Government Principles, proper use of research animals includes avoidance and minimization of discomfort, distress, and pain, as well as due consideration of the potential benefits of the research. Unless the contrary is established, procedures that cause pain in humans are assumed to cause pain in nonhuman animals.17 Procedures that cause more than momentary or slight pain or distress must be performed with appropriate sedation, analgesics, or anesthetics unless withholding of such agents is justified for scientific reasons and approved by the IACUC. Animals that would experience severe or chronic pain or distress that cannot be relieved must be painlessly euthanized at the end of the procedure, or if appropriate, during the procedure. No animal should be used in more than one major operative procedure from which it is allowed to recover unless justified for scientific reasons.
Both the National Academies Guide for the Care and Use of Laboratory Animals (NRC, 2011) and the American Veterinary Medical Association’s Guidelines for Euthanasia of Animals (AMVA, 2020) provide guidance on the disposal of nonhuman animal remains once an experiment has been completed. Both sets of guidelines focus on protecting the environment and other animals from infectious diseases or chemical contaminants, and indicate no differential considerations based on the characteristics of the animal. Researchers working with animals with human neural cell transplants or chimeric animals would follow these same guidelines.
The principles that underlie the U.S. approach to oversight of animal research are broadly accepted. The Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC International), a nonprofit organization that promotes the humane treatment of animals in science through voluntary accreditation and assessment programs, has accredited research facilities in 49 countries.18 Directive 2010/63/EU in the European Union includes the Three R’s and requires institutional oversight bodies similar to IACUCs.19 Both the EU Directive and AAALAC accreditation require protections for cephalopods in addition to vertebrate animals. China, Japan, and Singapore have also adopted guidelines to ensure appropriate oversight for the use and care of animals in research (NRC, 2012). Japan’s Act on Welfare and Management of Animals, most recently amended in 2014, explicitly incorporates the Three R’s principles.20
17NRC, 2011 (see Appendix B: U.S. Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research and Training, Principle IV); CIMS and ICLAS, 2012 (see Principle VII).
19 Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the protection of animals used for scientific purposes. See https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32010L0063.
20 Act on Welfare and Management of Animals (Act. No. 105 of October 1, 1973, as amended by Act No. 46 of May 30, 2014). See http://www.env.go.jp/nature/dobutsu/aigo/1_law/files/aigo_kanri_1973_105_en.pdf.
China in 2016 adopted its first national standards governing the treatment of laboratory animals, which cover euthanasia, pain management, transport and housing; breeding facilities; and personnel training (McLaughlin, 2016).
The use of nonhuman primates raises obligations that go beyond those required for other research animals. The AWA includes provisions to ensure the psychological well-being of nonhuman primates,21 including, at a minimum, addressing their social needs and social groupings, providing adequate environmental enrichment, and not maintaining them in restraint devices for longer than required to attain the approved scientific goals of the research or for more than 12 hours continuously. The AWA regulations require certain nonhuman primates to be provided special attention regarding enhancement of their environment, based on the needs of the individual species and in accordance with the instructions of the attending veterinarian. Nonhuman primates requiring special attention include infants and young juveniles; those that show signs of being in psychological distress through behavior or appearance; those used in research for which the committee-approved protocol requires restricted activity; individually housed nonhuman primates that are unable to see and hear nonhuman primates of their own or compatible species; and great apes weighing more than 110 lb.22 USDA conducts inspections of U.S. research institutions that conduct research on nonhuman primates to ensure compliance with the AWA. Institutions that conduct research on chimpanzees and other great apes take extra precautions to ensure compliance both to fulfill their ethical obligations to the animals and to meet the high expectations of the public.
In the United States, the use of nonhuman primates in research has received scrutiny in recent years, including legislation to limit the use of these animals.23 In December 2010, NIH commissioned a study by the Institute of Medicine (IOM) to assess whether and to what extent chimpanzees are necessary and will be necessary in the future for biomedical and behavioral research. The IOM issued its findings in 2011, with a primary recommendation that the use of chimpanzees in research be guided by a set of principles including (1) that the knowledge gained must be necessary to advance the public’s health; (2) that there must be no other research model by which the knowledge could be obtained, and the research cannot be ethically performed on human subjects; and (3) that the animals used in the proposed research be maintained either in ethologically appropriate physical and social environments or in natural habitats (IOM, 2011). The report concludes that chimpanzee research has been a valuable research animal model but that most
21 Animal Welfare Act (7 U.S.C. § 2143).
23 The Further Consolidated Appropriations Act, 2020 (Pub. L. 116-94, December 20, 2019) requires special authorization by the Secretary of Veterans Affairs for that agency’s research use of nonhuman primates, felines, or canines; requires NIH to explore alternatives to the use of nonhuman primates; and requires the FDA to develop a detailed plan for reduction and retirement of its monkeys.
current uses of chimpanzees for biomedical research are unnecessary. Later, a working group convened by an NIH advisory body evaluated specific experiments and went into more depth on the enhanced living conditions (CCWG, 2013). NIH subsequently announced plans to phase out much of the research that involves these animals (NIH, 2013) and no longer funds biomedical research on chimpanzees (Collins, 2015). NIH has continued efforts to improve the rigor and reproducibility of research involving nonhuman primates more broadly—for example, with a workshop on the topic in February 2020 (AAMC, 2020). Of note, privately funded research may continue and is not subject to the limitations and conditions recommended by the IOM and the NIH working group.
Animal welfare laws in many other countries are more restrictive than those in the United States regarding the use of nonhuman primates. Under the Directive 2010/63/EU, biomedical research on nonhuman primates is allowed only when no alternatives are available for basic research, when it is focused on preservation of the primate species, or when the work addresses potentially life-threatening or debilitating conditions in humans. Research involving chimpanzees and other great apes is allowed in very rare circumstances. The United Kingdom, Germany, the Netherlands, Sweden, Austria,24 Belgium, Japan, and New Zealand25 go further than the EU Directive and have policies or laws that essentially ban the use of great apes (but not monkeys) as laboratory animals (Knight, 2008; Should apes have legal rights, 2013). In these jurisdictions, a researcher seeking to transplant human cells into a nonhuman primate would face significant hurdles.
Table 4-2 summarizes U.S. laws, policies, and nonbinding guidance covering neural cell transplants and human neural chimeras. Beyond the provisions of the AWA and PHS Policy addressing research animals, there are no provisions in U.S. federal law specific to the generation of human-animal chimeras or to ensuring their welfare and well-being (although two U.S. states have laws barring the creation of some human neural chimeras26). In recent years, however, the use of human stem cells for neural cell transplants into nonhuman animals or for generation of human neural chimeras has been the subject of policy discussions at NIH. The
24 Austria’s Animal Experiments Act of 2012 prohibits animal experiments on the great apes and gibbons.
25 New Zealand’s Animal Welfare Act of 1999 restricts research involving the use of nonhuman hominids to research in the best interest of the species. See http://legislation.govt.nz/act/public/1999/0142/latest/DLM51206.html.
26 Arizona and Louisiana prohibit the generation of a “human-animal hybrid,” which is defined in part as a nonhuman life form engineered so that it contains a human brain or a brain derived “wholly or predominantly” from human neural tissue. The Louisiana law also includes a clause barring the creation of a nonhuman embryo into which human cells or cell components have been introduced (Louisiana Revised Statutes §14:89.6.A ; Arizona Revised Statutes Ann § 36-2311 ). See also Macintosh (2015).
|Procedure||Animal Use and Welfare Laws in the United States||National Institutes of Health (NIH) Guidelines and Policy Development (funding requirements)|
|Neural cell transplants made by grafting human cells into a fetal or postnatal nonprimate vertebrate (e.g., mouse) brain||Review by institutional animal care and use committees (IACUC)||Proposal for additional oversight of research that shows a “substantial contribution or a substantial functional modification to the animal brain by the human cells”|
|Neural cell transplant made by grafting human cells into a fetal or postnatal nonhuman primate brain||Review by IACUC, with additional protections and oversight for nonhuman primates, including measures to promote psychological well-being||Proposal for additional oversight of research that shows a “substantial contribution or a substantial functional modification to the animal brain by the human cells”|
|Chimera made by inserting human cells into a nonprimate vertebrate (e.g., mouse) blastocyst||Review by IACUC
Likely forbidden in Arizona and Louisiana
Proposal for additional oversight of research that shows a “substantial contribution or a substantial functional modification to the animal brain by the human cells”
Breeding is forbidden where human cells may contribute to germline. (NIH Guidelines for Human Stem Cell Research)
|Chimera made by inserting human cells into a nonhuman primate blastocyst||Review by IACUC, with additional protections and oversight for nonhuman primates, including measures to promote psychological well-being
Forbidden in California; likely forbidden in Arizona and Louisiana.
|Forbidden (NIH, 2009)|
NOTE: Additional oversight may apply if the human cells are derived from embryonic stem cells (ESCs) rather than induced pluripotent stem cells (iPSCs) or somatic sources (see Table 4-1).
Review required, with more careful consideration for fetal transplantation “because the extent of human contribution the resulting animal may be higher” (NRC and IOM, 2010)
Specialized review when the degree of functional integration into the central nervous system may substantially alter the animal host; best practices for ensuring animal welfare (ISSCR, 2016)
Review required, with more careful consideration for fetal transplantation “because the extent of human contribution to the resulting animal may be higher” (NRC and IOM, 2010)
Specialized review when the degree of functional integration into the central nervous system may substantially alter the animal host; especially rigorous for nonhuman primates; best practices for ensuring animal welfare (ISSCR, 2016)
Additional review, with particular attention to the level of functional integration of human cells into the animal; should be considered only under circumstances in which no other experiment can provide the information needed; breeding should not be allowed if human cells may contribute to germline (NRC and IOM, 2010)
Specialized review when the degree of functional integration into the central nervous system may substantially alter the animal host or when human cells may contribute to gametes; best practices for ensuring animal welfare (ISSCR, 2016)
This type of research should not be conducted at this time (NRC and IOM, 2010)
Specialized review when the degree of functional integration into the central nervous system may substantially alter the animal host or when human cells may contribute to gametes; especially rigorous for nonhuman primates; best practices for ensuring animal welfare (ISSCR, 2016)
2009 NIH Guidelines for Human Stem Cell Research27 prohibit NIH from funding research that introduces human pluripotent stem cells (hPSCs) into nonhuman primate blastocysts (the state of California has a similar prohibition for research funded by the state28). It also prohibits funding of research that involves breeding of any research animal whereby human stem cells may contribute to its germline.
In 2015, citing potential ethical and animal welfare concerns and in preparation for additional policy making, NIH issued a moratorium on its funding of research that introduces hPSCs into pregastrulation embryos of any nonhuman vertebrate animal.29 This moratorium still allows neural cell transplants in which human stem cells are introduced into fetal or postnatal animal brains, but prohibits techniques that introduce human stem cells at early embryonic stages, including blastocyst chimerism and complementation, discussed in Chapter 2.
After imposing the moratorium and hosting a workshop on the topic in November 2015 (OSP, 2015), NIH issued a notice of proposed changes to its guidelines to include the establishment of an NIH steering committee that would provide additional oversight for neural cell transplants and human neural chimeras. NIH proposed that this committee could oversee research involving the introduction of human stem cells early in embryonic development in any vertebrate animal, as well as studies (excluding those in mice) in which human stem cells introduced at any developmental stage could result in “a substantial contribution or a substantial functional modification to the animal brain by the human cells” (OSP, 2016). Such a policy would provide additional oversight for neural cell transplants and human neural chimeras of all types. NIH sought public input on the proposed changes in 2016,30 but they have never been finalized. The moratorium remains in effect.
The 2010 National Academies Guidelines for Human Embryonic Stem Cell Research, adopted in 2005 and last amended in 2010, explicitly use a three-tiered approach (see the further discussion of such an approach in the next section). The guidelines do not permit the injection of human stem cells (derived from embryos or other sources) into nonhuman primate blastocysts or breeding of nonhuman animals in which such cells could potentially contribute to the germline.31 The guidelines require additional review for research that introduces human ESCs (hESCs) into nonhuman animals at any stage of development. An ESCRO committee should oversee such research that may result in functional integration of the human cells into the animal. The guidelines provide similar oversight for
28 California Institute for Regenerative Medicine, CIRM Medical and Ethical Standards Regulations, § 100030(c) (available at https://www.cirm.ca.gov/sites/default/files/files/board_meetings/CIRM_MES_regulations_Full_Revised_07_17_2013.pdf).
29 September 23, 2015. Notice Number: NOT-OD-15-158. See https://grants.nih.gov/grants/guide/notice-files/NOT-OD-15-158.html.
30 81 Fed. Reg. 51921. Request for Public Comment on the Proposed Changes to the NIH Guidelines for Human Stem Cell Research and the Proposed Scope of an NIH Steering Committee’s Consideration of Certain Human-Animal Chimera Research. August 5, 2016.
transplantation into nonhuman animals of hPSCs derived from sources other than human embryos, requiring additional ESCRO review for experiments “where there is a significant possibility that the implanted hPS cells could give rise to neural or gametic cells and tissues.”32 For research involving the use of human stem cells in primates or in cases in which human stem cells may give rise to neural tissues in any nonhuman animal, “particular attention should be paid to at least three factors: the extent to which the implanted cells colonize and integrate into the animal tissue; the degree of differentiation of the implanted cells; and the possible effects of the implanted cells on the function of the animal tissue.”33
The National Academies guidelines, in sections related to the use of hESC lines, make a distinction between grafting of such cells into adult animal brains (which the guidelines consider to require a lower level of review) and grafting them into fetal animal brains, which would require “more careful consideration because the extent of human contribution to the resulting animal may be higher.”34 The guidelines flag these issues for ethical consideration, but do not offer additional guidance for ensuring the welfare or well-being of chimeras or nonhuman animals with neural cell transplants.
The 2016 ISSCR Guidelines for Stem Cell Research and Clinical Translation address research involving transplantation of human cells into nonhuman animal brains or generation of human-animal chimeras. Although these guidelines do not explicitly follow the three-tiered approach described above, they provide similar guidance. They state that research may require specialized review if human cells have the potential for a high degree of integration into an animal’s central nervous system or if they may generate human gametes in nonhuman animal hosts. If the research involves nonhuman primates, this review should be “especially rigorous.” The ISSCR guidelines also recommend best practices for ensuring animal welfare if and when “the degree of functional integration of human cells is considerable enough to raise concerns that the nature of the animal host may be significantly altered.” These best practices include: “(a) establishment of baseline animal data; (b) ongoing data collection of deviations from the norms of species typical animals; (c) the use of small pilot studies to ascertain welfare changes in modified animals; and (d) ongoing monitoring and reporting to oversight committee authorized to decide if there is need to change protocols or remove animal subjects from research.”35 As of this writing, these guidelines are undergoing review and revision but have not yet been issued.
Box 4-1 presents scenarios illustrating how different committees might oversee research involving human neural organoids or transplants.
Over the past several years, a three-tiered approach has been proposed for the guidance of research in biotechnological areas that raise substantial ethical and regulatory concerns.
The first tier is research that can be reviewed and approved by existing oversight mechanisms because it presents no new ethical or regulatory concerns beyond those the current oversight system is charged with addressing. Most current research discussed in this report involving human organoids, human neural cell transplants, and chimeras involving nonhuman donors and nonprimate hosts falls into this category.
The second tier is research that can proceed after additional review and approval. Broadly speaking, such research raises additional ethical concerns that the current oversight system, such as IRBs and IACUCs, is not designed to address. The additional review that is required for this tier of research may be carried out through institutional or national committees. Research that falls into this tier might include neural transplants that render the host’s brain more “human-like,” particularly in nonhuman primates.
The third tier is research that should not be permitted at the present time. This category includes experiments that are currently forbidden under U.S. law, including the introduction of hESCs or iPSCs into the blastocyst of a nonhuman animal.
Several National Academies committees have recommended a three-tiered oversight structure for other types of innovative biomedical research—for example, human genome editing (NASEM, 2017a, pp. 181–194). Several other countries have also adopted this approach, as described in the next section, which includes an expanded description of policies in the United Kingdom.
Table 4-3 provides examples of experiments involving human neural organoids, transplants, or chimeras that fall into each of these tiers under the current U.S. regulatory framework: (1) research that can proceed under existing oversight mechanisms, (2) research that may require additional review, and (3) research that should not proceed at this time.
The committee could find no laws, policies, or guidance at the national level in any country addressing the creation of human neural organoids beyond those focused on broad categories of in vitro research that might include such organoids. However, several countries have policies that include provisions for the transplantation of human stem cells into nonhuman animals, and these policies show a range of approaches. The ISSCR guidelines, described above, are influential in much of the world and provide additional relevant guidance for scientists and institutions. Laws that provide protections for animals used in research are
|Green Level of Scrutiny: Research That Can Proceed Under Existing Oversight Mechanisms|
|Neural Organoids||Neural Cell Transplants||Neural Chimeras|
|Generation of human neural organoids from human patient-derived iPSCs for use to understand human brain formation, identify disease-related abnormalities, and screen drugs that reverse those abnormalities||Transplantation of human ESC- or iPSC-derived neural progenitors into the nervous system of wild-type mice and mice that model brain disease to assess whether the milieu affects their differentiation, connections, and function||Generation of chimeras in which human ESCs or iPSCs are implanted into the blastocyst of a nonhuman animal and maintained solely in vitro|
|Yellow Level of Scrutiny: Research That May Require Additional Review|
|Neural Organoids||Neural Cell Transplants||Neural Chimeras|
|Experiments using iPSCs to generate neural organoids when there is ambiguity about the human donor’s consent.||Transplantation of large numbers of human ESC- or iPSC-derived neural progenitors into the cortex of a neonatal macaque such that integration into circuits might lead to altered behavior||Transplantation of human cells into mouse blastocysts followed by implantation into the uterus of a host mouse.|
|Red Level of Scrutiny: Research That Should Not Proceed at This Time|
|Neural Organoids||Neural Cell Transplants||Neural Chimeras|
|Experiments using iPSCs to generate neural organoids that violate the terms of the human donor’s consent||Studies where human stem cells introduced into nonhuman primate embryos with the aim of populating the developing neural tube could result in generation of donor-derived gametes in the host||Transplantation of human cells into blastocysts of nonhuman primates followed by implantation into the uterus of a host|
common in the developed world, as discussed above, and add another layer of oversight for this type of research.
Several countries have developed official policy or guidance on the transfer of human cells into nonhuman animals that follows the three-tiered approach to oversight described in the preceding section, identifying research that can proceed under existing oversight mechanisms; research that may require additional review; and research that should be prohibited.
In 2011, the German National Ethics Council issued additional guidance applying the Embryo Protection Act of 1990 to address newer laboratory techniques, including the possibility of using human iPSCs in human neural cell
transplants (GEC, 2011). The Council adopted a three-tiered approach to research oversight, stating that neural cell transplants made by the transfer of human cells into mammals other than primates is ethically acceptable if the objective of the research is of overriding importance to medically benefit humanity, the generally applicable ethical requirements of animal welfare are satisfied, and the human cells are transferred after the embryonic stage. A second tier of research, including research involving the transplantation of human cells into nonhuman primate brains, should undergo rigorous review by a national-level committee. The Council recommended that a national-level committee already established for the use of animals in research be tasked with oversight of these types of studies, and that particularly rigorous review be applied to research that may result in changes in the capabilities of an animal that are relevant to its moral status. Studies involving transplantation of human stem cells into the brains of great apes fall into the third tier and should be prohibited. The Embryo Protection Act of 1990 had essentially already placed fusion of nonhuman animal embryos with human embryos into the third tier by prohibiting this research.36
The United Kingdom Home Office adopted guidance of this type in 2016 in response to a report from the UK Academy of Medical Sciences (Academy of Medical Sciences, 2011). The policy lists three categories of research: (1) experiments that do not present issues beyond those of the general use of animals in research and should be carried out under the normal regulatory structures that govern other types of animal research; (2) experiments that are permissible pending specialist review by the Animals in Science Committee, a national expert body; and (3) a narrow range of experiments that should not be licensed because of a lack of scientific justification or very strong ethical concerns. Experiments that fall into the second tier (which require national-level review) include “substantial modification of an animal’s brain that may make the brain function potentially more ‘human-like’, particularly in large animals; experiments that may lead to the generation or propagation of functional human germ cells in animals; experiments that could be expected to significantly alter the appearance or behaviour of animals, affecting those characteristics that are perceived to contribute most to distinguishing our species from our close evolutionary relatives; and experiments involving the addition of human genes or cells to nonhuman primates (NHPs).” Experiments in the third tier (which should be prohibited) include “allowing the development of an embryo, formed by pre-implantation mixing of NHP and human embryonic or pluripotent stem cells, beyond 14 days of development or the first signs of primitive streak development (whichever occurs first); unless there is persuasive evidence that the fate of the implanted (human) cells will not lead to ‘sensitive’ phenotypic changes in the developing fetus; transplantation of sufficient
36 German Embryo Protection Act (October 24, 1990). § 7(1) of the Act prohibits, among other things, combining embryos with different genetic information to form a cluster of cells, using at least one human embryo. See https://www.bundesgesundheitsministerium.de/fileadmin/Dateien/3_Downloads/Gesetze_und_Verordnungen/GuV/E/ESchG_EN_Fassung_Stand_10Dez2014_01.pdf.
human-derived neural cells into an NHP as to make it possible, in the judgement of the national expert body, that there could be substantial functional modification of the NHP brain, such as to engender ‘human-like’ behaviour. . . ; and breeding of animals that have, or may develop, human derived germ cells in their gonads, where this could lead to the production of human embryos or true hybrid embryos within an animal.”37 Canadian science-funding agencies issued a policy statement in 2018 that also follows this three-tiered approach. It states that grafting or transferring of hPSCs into a nonhuman animal after birth is permitted for certain applications,38 but requires approval from an institutional research ethics board (similar to an IRB) and the Stem Cell Oversight Committee, a national-level committee under the auspices of the Canadian Institutes of Health Research. Prohibited research includes studies in which hESCs, embryonic germ cells, iPSCs, or other cells that are likely to be pluripotent are combined with or grafted or transferred to a nonhuman embryo or fetus (CIHR et al., 2018).
In Japan, prior to 2019, researchers were forbidden to grow nonhuman animal embryos containing human cells beyond 14 days or to transplant human-animal chimeric embryos into a surrogate uterus. In March 2019, however, the Japanese Ministry of Science announced guidance allowing Japanese researchers to use blastocyst complementation to inject human iPSCs into a nonhuman animal embryo for basic research, to produce better models with which to study human development and disease, and to create potential donor organs. Although this guidance does not explicitly follow the three-tiered approach, it requires that researchers apply for approval from an institutional ethics committee and a national-level Japanese special committee for research ethics to conduct this type of research (Zimmer, 2019). The guidance neither explicitly allows nor prohibits the use of nonhuman primates, although research on great apes is not allowed in Japan.
The Swiss Federal Act on Assisted Reproduction,39 enacted in 1998, forbids the introduction of hESCs into nonhuman animal embryos, but does not specifically address the introduction of human iPSCs (presumably because this scientific development was not anticipated at the time of enactment), leading to some confusion about whether such an experiment would be allowed (SAMS, 2009; Shaw, 2014). The Swiss National Advisory Committee on Biomedical Ethics (NEK) issued a report in 2006 addressing broader research involving the transplantation of human cells into nonhuman animals (NeK, 2007). The report highlighted concerns about transplantation into the brain, in part because the possibility of altered perception or consciousness of the animal could not be excluded. The majority
37 UK Home Office, Guidance on the use of Human Material in Animals, Advice Note 01/16, January 2016 (available at https://www.gov.uk/government/publications/guidance-on-the-useof-human-material-in-animals).
38 These experiments are permitted provided that (1) they are designed to reconstitute a specific tissue or organ to derive a preclinical model or to demonstrate that the cells are pluripotent, and (2) these nonhuman animals grafted with human stem cells will not be used for reproductive purposes.
39 The Swiss Federal Reproductive Medicine Act of December 18, 1998, SR 810.11, AS 2000 3055.
of the members of the NEK opposed the creation or formation of partial human structures within animal hosts because of the concern that the human-animal chimera would develop a rudimentary form of the perception, sensibility, experience, or consciousness of humans. A minority of members supported limited authorization if one could control the development of the host organism.
Oversight of research involving neural cell transplants and human neural chimeras in China is unclear. In 2003, the Ministry of Science and Technology and the Ministry of Health enacted the Ethical Guidelines for Research on Human Embryonic Stem Cells, which includes some oversight at the national and institutional levels for these cells (Liao et al., 2007), but it is not clear whether this oversight includes neural cell transplant or human-animal chimera research. Certainly, research of this type is moving forward in China. A team of U.S., Spanish, and Chinese researchers produced the first human-monkey chimera at the Chinese Academy of Sciences’ Kunming Institute of Zoology in July 2019 (Lin, 2020).40 In this study, human cells were added to a monkey embryo and allowed to mature for about a week (Regalado, 2019).
Issues Regarding Consent
As discussed above, human biospecimens and data used in research are commonly “deidentified,” at which point the donors are no longer considered human subjects, and with the exception of ensuring that initial donation conditions are honored, Common Rule oversight will not apply. However, DNA sequencing techniques combined with data from other sources have increasingly allowed for the reidentification of biospecimens that do not have such explicit identifiers, as has occurred multiple times in criminal investigations and prosecutions (Ram et al., 2018). If such techniques become widespread or common, this situation will raise both practical and ethical concerns. As NIH leadership has recently written, “With increasingly sophisticated genomic sequencing technology, interoperable databases, and artificial intelligence/machine learning approaches, the concept of being able to ‘deidentify’ biospecimens for future research use—the critical regulatory delineation between needing consent or not—is rapidly becoming obsolete” (Wolinetz and Collins, 2020). In an effort to address concerns about reidentification, new methods are being devised that obscure tell-tale sequence variants without unduly compromising data required for the success of research (Gürsoy et al., 2020). Other new methods allow analysis by researchers requesting access to data while protecting the privacy of individuals whose genomes are in the dataset (see, e.g., Mott et al., 2020). On the other hand, this is a fast-moving
40 The U.S. researcher on the team, Juan Carlos Izpisua Belmonte, is a professor at the Salk Institute for Biological Studies in San Diego, CA.
field, and it remains uncertain whether new data protection methods will be able to keep up with novel methods for reidentification.41
Another consent issue concerns potential future research with biospecimens. Because it is impossible to identify all potential future uses of biospecimens to be deposited in a biobank at the time informed consent is obtained, some have suggested an approach that places greater emphasis on an ongoing good governance model for the biobank than on initial consent for future uses of the biospecimens. O’Doherty and colleagues (2011) outline four principles for biobank governance intended to both protect participant interests and promote effective translational health research: (1) recognition of research participants and publics as a collective body, (2) trustworthiness, (3) adaptive management to reflect dynamic technologies or changes in the nature or purpose of the biobank over time, and (4) fit between the nature of a particular biobank and the specific structural elements of governance adopted (O’Doherty et al., 2011, 367–374). These principles form the basis for an adaptive governance framework.
Boers and Bredenoord (2018) also propose addressing future uses of research biospecimens within a governance framework. Rather than creating an exhaustive list of potential future uses (such as the use of tissues to create neural organoids), participants consent to donating tissue to a biobank with an explicitly described governance model. They agree to a broad range of research uses, subject to privacy protections; a biobank governance structure that addresses consent procedures, management of data and samples, withdrawal of consent, property rights, communication with donors, and commercial interests; ongoing engagement with participants and the public; and fair sharing of research benefits. When possible, information on foreseeable research projects or procedures can be provided at the time of initial consent, particularly if certain procedures are foreseen that are known to be sensitive, such as whole-genome sequencing or human-animal chimera research (Sugarman and Bredenoord, 2019).
Another potential model for incorporating a governance framework into biobank practices is the nonprofit UK Biobank,42 which has an Ethics and Governance Framework and an Ethics Advisory Committee that advises the UK Biobank Board on ethical issues that arise during the maintenance, development, and use of the biobank’s resources, including identifying relevant ethical issues and providing guidance on policies with ethical dimensions. The consent form43 informs the donor of the biobank’s practices but does not describe specific research uses.
Many bioethicists and other observers have argued, however, that some research raises ethical issues that may warrant specific informed consent when
41 Data protection methods encompass other methods in addition to encryption, including those that slightly perturb datasets to decrease the risk of reidentification while preserving utility for secondary analyses.
donated tissues will be used for these types of studies. The National Academies Guidelines for Human Embryonic Stem Cell Research state that specific informed consent should be required when human stem cells are used for transplantation into nonhuman animals.44 The ISSCR guidelines also recommend that researchers inform participants when their tissues might be used in this way,45 and the state of California has a similar requirement for research funded by the state.46 An interdisciplinary group of brain researchers and ethicists stated in 2018:
Currently, researchers using pluripotent stem cells or brain tissues generally disclose their plans to donors in broad terms. Given how much people associate their experiences and sense of self with their brains, more transparency and assurances could be warranted. Donors might wish to deny the use of their stem cells for the creation of, say, human–animal chimaeras” (Farahany et al., 2018).
With regard to procurement of human biological materials for neural organoid research, Hyun and colleagues (2020) write that donors should be informed that neural organoids will be generated. According to these authors, when researchers generate neural organoids using iPSC lines derived from deidentified tissue samples procured from tissue banks, “It cannot be assumed that tissue donors have given their consent for their participation specifically in brain organoid research” (Hyun et al., 2020).
The NIH Clinical Center’s Department of Bioethics convened a workshop in 2015 for bioethics scholars on the topic of broad consent for research with biological samples (Grady et al., 2015). The workshop, which predated the final changes to the Common Rule, considered the ethical acceptability of broad consent for future research on stored biospecimens. Workshop participants concluded that broad consent is generally appropriate for use of biospecimens in repositories but may not be appropriate for exceptional circumstances. Examples of the latter included research proposing to create gametes from iPSCs or engaging certain donor groups, such as those with rare or highly stigmatized disorders or indigenous groups. Research on neural organoids or transplantation of human cells into nonhuman animals was not specifically discussed in this workshop.
If the acquisition of new capacities is suspected in animals used in research involving neural transplants or chimeras, additional training may be needed for
46 California Institute of Regenerative Medicine Regulations, Cal. Code Regs. Title 17 § 100100 (Informed Consent Requirements).
evaluators. Some of those responsible for oversight for research animals believe that plans could be developed for species-specific needs that would take into account previous experience with the domesticated species, the behavior of the wild population, the needs of similar species, and preference testing (i.e., tests to determine which conditions and environments the animals prefer). If warranted, an IACUC could authorize a pilot program or require veterinary evaluations. Ensuring the welfare of a laboratory animal includes ongoing monitoring after the research has been approved for behaviors (such as those related to activity, feeding, and socializing) and sometimes physiological parameters (such as blood pressure, heart rate, and cortisol levels) that are not typical of the individual or the species. Researchers work with the attending veterinarian to address any concerns—for example, by adjusting the animal’s diet or caging or changing the experimental protocol. In addition, as discussed below, IACUCs could gain additional expertise on animal welfare from animal ethologists and animal behavior scientists if needed.
Addition of Ad Hoc Expertise
The existing institutional oversight committees for human neural organoid, transplant, and chimera research have specific regulatory charges, such as protection of human subjects for IRBs and animal welfare for IACUCs. If these local committees lacked sufficient expertise to review research studies on the topics discussed in this report, they could add members with relevant expertise—for example, in stem cell research, neurobiology, species-specific behaviors and needs, and animal ethics or religious studies. These members could join on an ad hoc basis. If needed, experts from other institutions could participate in meetings via videoconference.
Further Discussion of Oversight as the Research Develops
As is clear from the previous chapter, the research discussed in this report may invoke much broader ethical concerns that do not fall within the expertise or scope of these existing committees. As research involving human neural organoids, transplants, and chimeras advances, there may be additional opportunities at the national level for discussion of ethical issues and oversight. For example, the Novel and Exceptional Technology and Research Advisory Committee (NExTRAC) is a potential U.S. forum for future discussions on the ethical and regulatory issues associated with these research models. A successor to the Recombinant DNA Advisory Committee (RAC), NExTRAC was established in 2019 as a federal advisory committee to the director of NIH. It is tasked with making recommendations on the scientific, safety, ethical, and social issues associated with areas of emerging biotechnology research, but does not review individual protocols. As the new NExTRAC framework is being developed to
evaluate emerging biotechnologies or applications,47 one NExTRAC priority will be to advise NIH on effective communication and outreach on emerging biotechnologies. Research involving human neural organoids, transplants, and chimeras might be an appropriate topic for NExTRAC consideration if requested by the NIH director. As an advisory committee, however, NExTRAC can only offer recommendations to NIH leadership, who then must decide whether to accept and implement them.
NIH has also used workshops (such as those mentioned above) and expert committees with narrower purview to gain helpful insight into complex topics. For example, the Neuroethics Subgroup of the BRAIN Initiative has provided guidance relevant to ethical issues in neuroscience.48 Such venues can provide timely and highly relevant perspectives. More broadly, the U.S. government has used multiple types of entities to provide insight on bioethical issues. Congress established two bioethics commissions: the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research (1974–1978) and the President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research (1980–1983). In addition, each U.S. president from 1996 to 2016 appointed a bioethics council or commission to study scientific issues with ethical dimensions. The National Bioethics Advisory Commission (1996–2001),49 the President’s Bioethics Council (2001–2009), and the Presidential Commission for the Study of Bioethical Issues (2009–2017) released reports on such issues as stem cell research (PCB, 2004), human cloning (PCB, 2002), human research subjects (PCSBI, 2011), and topics in neuroscience (PCSBI, 2015). Although these activities can be valuable, they are sometimes seen as guided in part by political influence because their members are appointed by the President. As mentioned throughout the present report, reports commissioned from the National Academies have also been influential in these discussions as offering consensus, peer-reviewed expert perspectives. Whether these mechanisms, separately or in combination, are useful for dealing with ethical issues that might be raised by these kinds of research in the future is beyond the scope of this report.