Computed tomography (CT) or computer-assisted tomography (CAT)

Diagnostic imaging method in which X-ray measurements obtained from many angles are combined into a single image. CT scans help physicians evaluate bone structures and bleeding within the skull and spine.

Contusion

A bruising injury. Spinal cord contusions result in a cavity or hole in the center of the spinal cord. Myelinated axons typically survive around the perimeter of the spinal cord, and the dura may even remain unbroken by the injury.

Corticospinal tracts

The nerve fibers that carry signals from the motor control areas of the brain’s cerebral cortex to the spinal cord.

Cyclic AMP (cAMP)

An adenosine-based mononucleotide that mediates hormonal effects and that acts as a second messenger.

Cytokines

Chemical messenger molecules by which immune cells communicate with one another and with other cells. Some nerve cells also use cytokines as messenger molecules.

Cytoskeleton

The internal scaffolding of cells. The cytoskeleton determines the cell shape, organizes structures within cells, and helps cells and growth cones of developing axons move.

Dendrites

The tree-like branches from nerve cell bodies that receive and integrate signals from other nerve cells at synapses.

Deoxyribonucleic acid (DNA)

Basic unit of heredity. DNA consists of a double helix containing ribose sugars, nucleic acids, phosphate groups, and hydrogen bonds.

Dermatome

Predefined regions of the skin that are innervated by nerve fibers and tested (via a pinprick or light touch) to determine sensory response.

Descending pathways

Nerve pathways that go down the spinal cord and that allow the brain to control the movement of the body below the head and autonomic function.

Dorsal

Relating to the back or posterior of an animal.

Excitotoxicity

Excessive release of neurotransmitters causing damage to nerve and glial cells. Excitotoxicity probably contributes to damage following nervous system trauma and stroke and may also contribute to some neurodegenerative diseases. Glutamate, the most prevalent neurotransmitter by which nerve cells excite (activate) one another, is often involved in excitotoxicity.

Extracellular matrix

The material that surrounds cells. Important regulatory molecules in the extracelluar matrix promote, inhibit, or guide the growth of axons.

F30 fellowship

Federally supported fellowship sponsored by the National Institutes of Health and given to predoctoral students seeking combined M.D. and Ph.D. degrees. These fellowships were created to increase the number of physician-researchers in the field of mental health,