Neurotransmitters

Question 1

criteria for being classified as a NT

Answer 1

manufactured in neurons, released by neurons in response to activity, receptors, mechanism of termination (diffusion, degradation, reuptake)

Question 2

categories of NT

Answer 2

Amino Acids: glutamate, GABA, glycine; Amines: acetylcholine, dopamine, norepinephrine, epinephrine, seratonin; Peptides: much larger, genetically encoded; endocannabinoids; Gases: NO, CO; ATP

Question 3

peptide NT synthesis, storage, release, and elimination

Answer 3

synthesis of NT precursors and enzymes in nucleus, transport of enzymes and pre-preptide precursors down microtubule tracks, enzymes modify pre-peptides to produce peptide NT, peptide NT often released with small molecules NTs, peptide NT often singal via metabotropic receptors, NT diffuses away and is degraded by proteolytic enzymes

Question 4

small molecule NT synthesis, storage, release, and elimination

Answer 4

synthesis of enzymes (vesicular transporters, synthesizing enzymes, SNARE) in cell body, slow axonal transport of enzymes, synthesis and packaging of neurotransmitter at axon terminal, release and diffusion of NT, transport of precursors back into terminal (precursors recycled using membrane reuptake transporter)

Question 5

amino acid NT synthesis, storage, release, and elimination

Answer 5

Glu: flutamate transporter uses cotransport to bring 2 Na+ and Glu into the cell, protein pump uses ATP to pump H+ into vesicle, countertransport occurs as concentration gradient is used to power import of NT into vesicle as H+ rushes out
GABA: same process except glu -> GABA using GAD

Question 6

Ach synthesis, storage, release, and elimination

Answer 6

choline transporter pumps choline into cell, choline and acetyl CoA combine using the enzyme ChAT to form ACh, ACh transporter uses counter transport with H+ to get ACh into vesicle, AChE degrades ACh into choline and acetic acid

Question 7

catecholamine

Answer 7

tyrosine imported into cell, tyrosine -> DOPA by tyrosine hydroxylase -> dopamine by DOPA decarboxylase -> norepinephrine by DBH -> epinephrine by PNMT, brought into vesicle by VMAT

Question 8

serotonin

Answer 8

tryptophan -> 5-HTP by tryptophan hydroxylase -> serotonin by 5-HTP decarboxylase, brought into vesicle by VMAT, terminated by reuptake

Question 9

gas and endocannabinoid

Answer 9

don’t need to be stored or in vesicles because they go through the membrane, NEED MORE INFO

Question 10

ATP

Answer 10

????