Neurophysiology - L3 Flashcards
Electric Synapse (what they use, and description)
Uses Gap junction made of 6 peice connexin. Each side of axon will donate half the junction. They share the cytosol. Very fast and has low synaptic delay
seen in the heart
Chemical Synapse (general mechanism, what ion is absolutely needed)
Has a 1ms synaptic delay.
secretes NT to cross to the other side.
Use Calcium to go. It is the largest driving force, and all you really need to have a muscle response
Quantal Release
A packet of NT in a vesicle being released across the cleft
Endplate Potential
The normal post synaptic response from a large release of quantum
Mini EPP
The rise in potential on the post synapse caused by one packet of NT being released
SNARE Proteins (Name Them and function)
Various Proteins implicated in control of exocytosis
Synapsin - Attaches vesicle to cytoskelton near terminus
SynaptoBrevin - anchors vesicle to the terminus
Synaptotagmin- calcium activated switch causing fusion to in to the cleft
BoTox Affect
hydrolyzes synaptobrevin and causes muscle paralysis
Three ways Ach is taken out of the cleft
Diffusion
Choline Esterase
Sodium coupled transporters back to presynapse
Ionotropic Receptor
Receptor is the ion channel - 2 Ach needed.
Metabotropic Receptor
Is G protein coupled. The NT hits receptor activating the G protein. Which thus creates second messenger able to be modified and amplified
Ion Flow of Ionotropic Receptor
Both Na and K flow at the same rate
EPSP/IPSP
EPSP - anything that is causing the voltage to go toward the threshold
IPSP - anything that is causing the voltage to go away from the threshold
Axon Hillock
Location that makes the decision to fire an action potential. Done through temporal and spacial summation
Temporal and Spacial Summation
Temporal - AP close in time from the same source
Spacial - Many incoming action potentials from different places merging on the axon hillock
