lecture 8 Flashcards
(49 cards)
2 classes of neurotransmitters
- small molecules can synthesize with precursors - peptides streams of amino acids require Golgi and ER to make
classes of small molecule NTs
acetylcholine amino acids purines catecholamines - dopamine, nor/epinephrine indoleamine- serotonin imidazoleamine- histamine
small molecules that aren’t in vesicles
endocannabinoids - lipid soluble
nitric oxide and carbon monoxide - gas
adenosine - made from ATP
peptide NT com position
around 3-30 amino acids long
how can you find a neutron releasing a specific NT
look for the enzyme that is used to make that transmitter because the neuron will only spend energy making that enzyme if it needs it
acetylcholineaseteras
Ach esterase - converts acetylcholine to acetate + choline
gets rid of Ach in synapse so receptor doesn’t keep responding which prevents desensitization
choline acetyl-transferase
ChAT - makes acetylcholine from acetyl CoA + choline
transport system to load vesicles
requires ATP to form a proton gradient by driving protons into vesicle
toxins that bind postsynaptic receptors
bungarotoxin- cobra - nACh antagonist
epibatidine- frog- n and m AChR
conotoxin- snail - block Glu and ACh receptors (N type)
arecoline - betel nut- m AChR agonist
key to normal N.S
balance between inhibition and excitation
many toxins take advantage of this
general structure of ligand gated receptor
5 subunits
why do each receptors require 2 Act molecules
increases the steepness of the relationship between concentration of ACh and release
larger difference between ACh increasing or decreasing in concentration
3 glutamate receptors
AMPA
NMDA
kainate
AMPA
Glu R1
Glu R2- calcium impermeable
Glu R3
Glu R3
all classes of ligand gated receptors (ionotropic)
AMPA, NDMA Kainate GABA Glycine nACh serotonin purines
myasthenia gravis
autoimmune disease that attacks nACh receptors in neuromuscular junctions which causes disorganization and weakness
treatment- ACh esterase inhibitor that keeps ACh around in synapse longer alleviation of symptoms
structure of metabotropic receptors
doesn’t have a pore- no ion movement
activates a G protein that goes on to produce cellular affects
classes of metabotropic receptors
glutamate, GABA dopamine NE, Epi histamine serotonin purines muscarinic
glutaminase
converts glutamine to glutamate
how is glutamate recycled
transferred from neuron to glia through excitatory amino acid transporters
enzyme - glutamine synthetase
NDMA receptors
both voltage and ligand gated receptor
NDMA receptor requirements
glycine - required modulator (co-ligand) 2 glutamates- to bind Mg- voltage dependant blocker during depolarization magnesium comes away and receptor becomes activated Ca- contribute to current
why does NMDA receptor current get smaller around -60mV
once the membrane potential passes -60 and starts to approach 0 the electrochemical gradient gets smaller (approaches reversal potential) and therefor so does the current
what happens to NDMA current when theres no magnesium
without magnesium the receptor doesn’t behave like a voltage dependant and there will be a linear relationship
