Exam 2 metabolism of neurotransmitters Flashcards
What is the enzyme for synthesis of acetylcholine
Choline acetyltransferase
What is the enzyme for degradation of acetylcholine
acetylcholine esterase
What is the enzyme for synthesis of gulamate?
Glutaminase
Is glutamate generally inhibitory or excitatory?
excitatory
Is GABA typically inhibitory or excitatory?
Inhibitory
What is the enzyme for synthesis of GABA?
glutamic acid decarboxylase
What is the enzyme for glycine and what amino acid is its derivative?
Serine hydroxymethyltransferase; serine
What is the amino acid derivative of serotonin?
tryptophan
What does breakdown of biogenic amines (dopamine) result in?
homovanillic
What proteins do botox poisons act on?
vesicle docking proteins (SNARE)
What is faster at moving down an axon: peptide neurotransmitter or small-molecule neurotransmitter
Peptide NT
How does lidocaine work?
block Na+ channels
how does DOPA work in treating neurological issues?
Increases dopamine production
How do methamphetamines cause their effects?
increase the release of dopamine and serotonine
How does cocaine cause its effect?
prevents reuptake of dopamine
What are the different glutamate receptors? Excitatory or inhibitory?
AMPA, NMDA (excitatory) and metabotropic receptors (inhibitory)
What kind of channel is GABAa?
chloride channel, hyperpolarizes the cell
What kind of channel is GABAb?
metabotropic receptor, inhibits adenylyl cyclase, augments K channels
What neurotransmitter receptors do benzodiazapines target?
GABA receptors to cause sedation
What would be the effect of removing GABA influence?
increase the amount of action potentials causing muscles to fire rapidly
What is the effect of Glycine?
Inhibitory NT of the spinal cord and brainstem, allows Cl- inside the cell
What are the two dopamine receptors and what is their effects?
D1= stimulate motor unit, D2= inhibits motor unit
How does dopamine interacting with D2 receptors cause its effects?
suppresses GABA release
What are the functions of the dopamine pathway?
Reward, pleasure, fine tuning motor function
What is the effect of norepinephrine?
acts via alpha2 receptors to increase potassium conductance–> hyperpolarizes cell
What are the two serotonin receptors and their effects?
5HT2a is metabotropic and is inhibitory. 5HT3 is ionotropic and excitatory
What are the targets of SSRIs?
5HT2a receptors, creating an anti-depressant effect
What are the functions of the serotonin pathways?
Mood, memory processing, sleep, cognition
How do opioids work?
suppress pain by interacting with a u (mew) receptor, decreasing calcium and cAMP
What part of the CNS does opioids work on?
spinal cord
What are the main categories of neurotransmitter?
Biogenic amines (acetylcholine, GABA, glutamate, etc.) and Neuropeptides (opioid peptides, glucagon-related peptides)
What criteria is used to ID a neurotransmitter?
NT is present in presynaptic terminal, NT is released during AP, NT interacts with receptors, NT has an application that can be agonist or antagonist
What are key features of the NMDA receptor?
has 7 subunits, is a sodium channel (excitatory), can be activated by glutamate
What is an excitotoxin?
able to over excite the neuron and causes too much calcium and sodium to enter the cell leading to swelling with H2O and cell death
What is the major inhibitory NT of the brain?
GABA and glycine
How is GABA synthesized?
Glutamate –(glutamic acid decarboxylase and pyridoxal phsophate)–>GABA
what amino acid is the precursor to catecholamine biosynthesis?
tyrosine
how are catacholamines inactivated in the synapse?
inactivated via methylation and oxidation
what is the pathway of serotonin biosynthesis?
Tryptophan –(tryptophan hydroxylase)–> 5-HTP –(5-HTP decarboxylase)–> serotonin (5-HT)
What are the products of norepi and dopamine catabolism?
Norepinephrine breaks down into vanillylmandelic acid (VMA) and dopamine breaks down into homovanillic acid (HVA)
What is anandamide?
an endocannabinoid that is created in the post-synaptic neuron and transported retroactively to the pre-synaptic neuron (Retrograde messenger)
What is the rate limiting step of catacholamine synthesis?
Tyrosine hydroxylase
What is pathway of acetylcholine synthesis?
acetyl-CoA + choline –(choline acyltransferase)–> acetylcholine
What is pathway of acetylcholine degradation
Acetylcholine + H2O–(acetylcholine esterase)–>acetate + choline
What is pathway of opioid metabolism
Pre-propeptide is proteolyzed down into small peptides
