Synapses and Neurotransmitter Flashcards
What is a synapse?
Functional connection between a neuron and the cell signaling
Neuromuscular junction
relationship between an neuron and muscle
Synapse in the CNS
second post another neuron
Synapse in the PNS
second postmuscle or gland
Presynaptic neuron is
the neuron signaling another neuron
Postsynaptic
The second neuron being signalled
Electrical synapses use
Gap Junctions
Chemical Synapses
Use neurotransmitter
Where do electrical synapses occur
in smooth muscle, cardiac, between neurons of the brain and glial cells.
In chemical synapses release a neurotransmitter from
the terminal buttons
What are cell adhesion proteins
pre and post synaptic cells are held together
release of a neurotransmitter (ca+)
Docking
Fusion
Exocytosis
Ca++ and synaptic vesicle docking
vesicles are docked to the plasma membrane by SNARE proteins
When Ca++ enter cell it binds to
synaptotagmin
What does synaptotagmin complex
displaces part of the snare which fuses the vesicle to the membrane so exocitosis happens
What is another word for Neurotransmitter
Ligand
What is the action of the NT
to diffuse across the synapse where it binds to a specific receptor protein
Excitatory Postsynaptic Potential (depolarization)
Opening Na+ or Ca++ channels
Inhibitory Postsynaptic potetial (Hyperpolarization)
Opening K+ or Cl-
EpSP
closer to threshold (depolarizes)
IPSP
moves farther from threshold (hyperpolarizes)
What is a summation of EpSp and IpSPs
Wether a AP occurs
What is spatial summation
occurs due to convergence of signals into a single postsynaptic neuron
What is temporal summation
due to successive waves of NT release over a short period of time
What is convergence
several different presynaptic neurons (synapse on 1 postsynaptic neuron)
What is divergence
axons have many branches so one presynaptic neuron can form synapses w/ several post synaptic neurons
