physiology notes: Neurophysiology Addendum

Addenda

MONOAMINES

Epinephrine, norepinephrine, dopamine and serotonin

Epinephrine, norepinephrine and dopamine are derived from tyrosine (catecholamine)

Serotonin is derived from tryptophan

Use second messengers: cAMP

Serotonin: in milk, turkey: affects mood and behavior; Appetite: Prozac blocks uptake

of serotonin

Dopamine: from substantia nigra (midbrain); coordination of skeletal movements;

Parkinson disease: deficiency; treated with L-dopa; may be due to nitric oxide

Produced by overactive microglia; dopamine in limbic system± emotions;

Schizophrenia associated with > amounts of dopamine receptors

Norepinephrine: arousal; associated with amphetamines

AMINO ACIDS

Glutamic acid and aspartic acid: excitatory: one type of glutamate receptor resembles

Angel dust

Glycine: inhibitory: strychnine poison blocks glycine receptors; cannot relax diaphragm

GABA: gamma-aminobutyric acid; inhibitory; most prevalent neurotransmitter in

Brain; deficiency= Huntington’s Disease

POLYPEPTIDES

Endogenous opioids; endorphins

Neuropeptide Y: inhibits glutamate preventing convulsions; most powerful stimulator of

Appetite; leptin from adipose tissue; inhibits neuropeptide Y release

NITRIC ACID

From L-arginine; dilation of blood vessels; may relate to learning and memory in brain;

Smooth muscle relaxation.

CARBON MONOXIDE; can promote olfactory adaptation