Neurotransmission Flashcards
type of ion involved in transmitting signal from one cell to the next
calcium
where are transmitter-gated ion channels found?
post-synaptic membrane
what happens to neurotransmitter once it activates transmitter-gated ion channels? (2 possibilities)
- uptake by pre-synaptic cell or glial cells
2. destruction by enzymes found in synaptic cleft
what mediates uptake of neurotransmitter by pre-synaptic cell?
sodium-dependent neurotransmitter symporters
two types of neurotransmitters
excitatory and inhibitory
ion channels opened by excitatory neurotransmitters
sodium and/or calcium
ion channels opened by inhibitory neurotransmitters
potassium and/or chlorine
how do inhibitory neurotrnsmitters work?
influx of potassium/chlorine makes it difficult for depolarization to occur
examples of excitatory neurotransmitters
acetylcholine (usually)
glutamate
serotonin
examples of inhibitory neurotransmitters
GABA (gamma-amino butyric acid)
glycine
describe the neuromuscular junction
between a motor neuron and a skeletal muscle cell
type of AAs lining the pore of the acetylcholine receptor
negative polar
function of acetylcholinesterase
hydrolyzes free acetylcholine in the neuromuscular junction to reduce its concentration
where are calcium-release channels found?
sarcoplasmic reticulum membrane
function of calcium-release channels
allow flow of calcium ions from SR lumen into cytosol
what causes myofibril contraction?
influx of calcium ions into cytosol (from SR lumen, via calcium-release channels)
what transporter facilitates myofibril contraction?
calcium-release channels in the sarcoplasmic reticulum membrane
condition for LTP
when a pre-synaptic cell fires (once or more) when the post-synaptic cell is already strongly depolarized
NMDA is doubly-gated: meaning?
NMDA receptors require 2 conditions for opening:
- glutamate must be bound
- membrane must be strongly depolarized
conditions for opening of NMDA receptors
- glutamate must be bound
2. membrane must be strongly depolarized
which receptor is critical for LTP?
NMDA receptors, a type of glutamate-gated ion channels
