neurotransmitter adenosine (ATP) - ANSWER The molecule that is the cell's energy source. The hydrolysis of ATP to produce adenosine diphosphate (ADP)
... [Show More] releases that fuels most of the biochemical reactions energy of the neuron. ADP is converted back to ATP in the mitochondria.
adenylyl cyclase - ANSWER An that catalyzes the enzyme conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP), a second messenger.
adrenal cortex - ANSWER The outer segment of the adrenal gland; releases cortisol when stimulated by the pituitary adrenocorticotropic hormone.
adrenal medulla - ANSWER The inner segment of the adrenal gland, innervated by preganglionic sympathetic fibers; releases epinephrine.
adrenaline - ANSWER A catecholamine neurotransmit- ter synthesized from norepinephrine; also called epinephrine.
adrenocorticotropic hormone (ACTH) - ANSWER A hor- mone released by the anterior pituitary in to corticotropin-releasing hormone; stimulates the response release of cortisol from the adrenal gland.
affective aggression - ANSWER A threatening or defensive form of aggression accompanied by vocalizations and a high level of ANS activity.
affective disorder - ANSWER A psychiatric condition charac- terized by disordered emotions; also called mood disorder. Examples are major depression and bipolar disorder.
affective neuroscience - ANSWER The study of the neural basis of mood and emotion.
afferent - ANSWER An axon coursing toward and innervating a given structure. See also efferent.
after-hyperpolarization - ANSWER The hyperpolarization that follows strong depolarization of the membrane; the last part of an action potential, also called undershoot.
agnosia - ANSWER The inability to recognize objects, even though simple sensory skills appear to be normal; most commonly caused by damage to posterior parietal areas of the brain.
agoraphobia - ANSWER A mental disorder characterized by severe anxiety about being in situations in which escape might be difficult or embarrassing.
alpha motor neuron - ANSWER A neuron that innervates the extrafusal fibers of skeletal muscle.
amacrine cell - ANSWER A neuron in the retina of the eye that projects neurites laterally in the inner plexiform layer.
amino acid - ANSWER A chemical building block of protein molecules, containing a central carbon atom, an amino group, a carboxyl group, and a variable R group.
Ammon's horn - ANSWER A layer of neurons in the hippocam- pus that sends axons into the fornix.
amnesia - ANSWER A severe loss of memory or the ability to learn. See also anterograde amnesia, retrograde amnesia.
AMPA receptor - ANSWER A subtype of glutamate receptor; a glutamate-gated ion channel that is permeable to Na+ and K+.
ampulla - ANSWER The bulge along a semicircular canal, which contains the hair cells that transduce rotation.
amygdala - ANSWER An almond-shaped nucleus in the anterior temporal lobe thought to be involved in emotion and certain types of learning and memory.
anabolism - ANSWER The biosynthesis of organic molecules from nutritive precursors; also called anabolic metabolism. See also catabolism.
analgesia - ANSWER The absence of normal sensations of pain. [Show Less]