Lecture 9: Synaptic Transition Flashcards
what is a synapse?
places where neurons communicate with each other
in diagrams they are usually depicted as one presynaptic neuron but in reality each neuron has many synapses
what are the two types of synapses?
- chemical
- electrical
chemical synapse
-uses neurotransmitters for signaling
-has a distinct cleft
-represents majority of synapses
electrical synapse
-uses electrical signals
-pre and post synaptic neurons are physically close (there is NO cleft)
-faster than chemical
know the diagram (AND THE ORDER) of the synaptic transition process
Order:
1. Action potential arrives at axon terminal
2. voltage gated Ca2+ channels open
3. Ca2+ enters the axon terminal
4. Ca2+signals to neurotransmitter vesicles
5. vesicles move to the membrane and dock
6. neurotransmitters are released via exocytosis
7. neurotransmitters bidn to ion channels
8. signal is initiatied in post-synaptic cell
know the diagram for the termination of synaptic transmission
:)
what are the 3 options for termination of synaptic transmission?
- reuptake
- enzymatic degradation
- diffusion
reuptake
an option for termination of synaptic transmission
-neurotransmitters are taken back up by the original presynaptic neuron
-pumps on presynaptic neuron and pumps on astrocytes
enzymatic degradation
an option for termination of synaptic transmission
neurotransmitters are thanos snapped from the synapse (not rlly but just pretend)
what is diffusion (in terms of neurotransmitters)
an option for termination of synaptic transmission
-neurotransmitters are reabsorbed back into the blood stream
what are the excitatory neurotransmitters?
-glutamate
-histamine
what are the inhibitory neurotransmitters?
-GABA
-Serotonin
what are the modulatory neurotransmitters?
Acetylcholine
norepinephrine
what do excitatory neurotransmitters do?
depolarize the post-synaptic cell
using Na+ channels
what do inhibitory neurotransmitters do?
hyperpolarize the cell
using Cl- channels and allowing positive ions out
