-
Acetylcholine (Ach); Locations and Actions?
Locations: Neuromuscular junctions, most synapses of autonomic nervous system, retina, and many parts of the brain
Actions: Excites skeletal muscles, and has excitatory or inhibitory effects on smooth muscle and glands depending on location
-
Glutamate (excitatory amino acid); Locations and Actions?
Locations: Cerebral cortex and brainstem, retina
Actions: Accounts for about 75% of all excitatory synaptic transmission in the brain; involved in learning and memory
-
Aspartate (excitatory amino acid); Locations and Actions?
Locations: Spinal cord
Actions: Effects similar to those of glutamate
-
Glycine (inhibitory amino acid); Locations and Actions?
Locations: Inhibitory neurons of the brain, spinal cord, and retina; (most common in the spinal cord)
Actions: Inhibitory neurotransmitter
-
GABA (γ-aminobutyric acid)(inhibitory amino acid); Locations and Actions?
Locations: Thalamus, hypothalamus, cerebellum, occipital lobes of cerebrum, and retina; (most common inhibitory neurotransmitter in the brain)
Actions: Inhibitory neurotransmitter
-
Norepinephrine (monoamine/catecholamine); Locations and Actions?
Locations: Sympathetic nervous system, cerebral cortex, hypothalamus, brainstem, cerebellum, and spinal cord
Actions: Involved in dreaming, waking, and mood; excites cardiac muscle; can excite or inhibit smooth muscle and glands depending on location
-
Epinephrine (monoamine/catecholamine); Locations and Actions?
Locations: Hypothalamus, thalamus, spinal cord, and adrenal medulla
Actions: Effects similar to those of norepinephrine
-
Dopamine (monoamine/catecholamine); Locations and Actions?
Locations: Hypothalamus, limbic system, cerebral cortex, and retina; (highly concentrated in substantia nigra of midbrain)
Actions: Involved in elevation of mood and control of skeletal muscles
-
Serotonin (monoamine); Locations and Actions?
Locations: Hypothalamus, limbic system, cerebellum, retina, and spinal cord; also secreted by blood platelets and intestinal cells
Actions: Involved in sleepiness, alertness, thermoregulation, and mood
-
Histamine (monoamine); Locations and Actions?
Locations: Hypothalamus; also secreted by mast cells of connective tissue and basophils of the blood
Actions: Potent vasodilator, bronchoconstriction, bronchial smooth muscle contraction, separation of endothelial cells (responsible for hives), and pain and itching due to insect stings; the primary receptors involved in allergic rhinitis symptoms and motion sickness; sleep regulation; (actions depend on which histamine receptors (H1-H4) histamine binds)
-
Substance P (neuropeptide); Locations and Actions?
Locations: Basal nuclei, midbrain, hypothalamus, cerebral cortex, small intestine, and pain-receptor neurons
Actions: Mediates pain transmission
-
Enkephalins (neuropeptide); Locations and Actions?
Locations: Hypothalamus, limbic system, pituitary, pain pathways of spinal cord, and nerve endings of digestive tract
Actions: Act as analgesics by inhibiting substance P; inhibit intestinal motility; secretion increases sharply in women in labor
-
β-endorphin (neuropeptide); Locations and Actions?
Locations: Digestive tract, spinal cord, and many parts of the brain; also secreted as a hormone by the pituitary
Actions: Suppresses pain; reduces perception of fatigue and may produce "runner's high" in athletes
-
Cholecystokinin (CCK)(neuropeptide); Locations and Actions?
Locations: Cerebral cortex and small intestine
Actions: Suppresses appetite
|
|
