neurotransmitters Flashcards
excitatory (inhibitory in vagus nerve)
in CNS, neuromuscular junctions, parasympathetic NS
role - muscle contractions/cognition
removal- degraded by enzyme acetylcholineesterase
ass disorders/drugs - alzheimers - deficiency
botox blocks it
Acetylcholine (ACh)
amino acid
excitatory
CNS - most common excitatory neurotransmitter in brain
removal - re-uptake
Glutamate/aspartate
amino acid
inhibitory
CNS - most common inhibitory neurotransmitter
removal - re-uptake
Gamma-aminobutyric acid (GABA) & Glycine
type - catecholamine
produced by tyrosine
excitatory
sympathetic NS, motor neurons, brain & adrenal medulla
removal - reuptake or degradation by enzymes
adrenaline/noradrenaline
epinephrine/norepinephrine
2 enzymes which degrade adrenalin/noradrenalin
monoamine oxidase (MAO) catechol-oxygen-methyl transferase (COMT)
type - catecholamine
excitatory/inhibitory
brain (primarily substantial nigra)
removal reuptake or degradation by MAO & COMT
dopamine
ass disorders dopamine
parkinson’s disease
produced by tryptophan
brainstem, digestive tract, blood platelets, pineal gland
removal - reuptake or degradation by enzyme MAO
serotonin (5-hydroxytrptamine)
found in neurone & astrocytes catalyses breakdown of some neurotransmitters - serotonin epinephrine norepinephrine dopamine
monoamine oxidase enzyme (MAO)
catalyses breakdown of epinephrine norepinephrine dopamine not serotonin
catechol-oxygen-methyl tranferase
formed from arginine - on demand, not in advance & stored
highly reactive signalling molecule & free redical
combines with 02, H20 to form nitrites & nitrates
vasodilation
used for angina, lowering BP and erections in males
Nitric Oxide
small proteins acting as neurotransmitters and sometimes as hormones
neuropeptides
enkephalins
endorphins
dynorphins
& substance P are common
neuropeptides
