Synaptic Transmission Flashcards
How can neuronal morphology be mapped?
using a golgi stain
What is an electrical synapse?
a synapse with no gap between the pre and post-synaptic terminals, action potential travels directly
What is a chemical synapse?
action potential travels by neurotransmitters being released from a presynaptic terminal and acting on postsynaptic receptors
What is an axodendritic synapse?
an axon connecting to a dendrite (most common)
What is an axosomatic synapse?
an axon connecting to a soma
What is an axoaxonic synapse?
an axon connecting to another axon
What are classical neurotransmitters?
amino acids; glutamate, GABA, glycine
monoamines; DA, NE, 5-HT
acetylcholine
What are non-classical neurotransmitters?
neuropeptides
gases
lipids
How are classical neurotransmitters synthesised?
dietary precursors cross the BBB where enzymes in the axon terminals synthesise them into neurotransmitters and pack them into vesicles
How are non-classical neurotransmitters synthesised?
neuropeptide transmitters are synthesised in the cell body
What are the 3 R’s of neurotransmitter storage?
readily releasable pool; docked to cell membrane, rapid release, rapid depletion
recycling pool; mobilised by moderate stimulation, fairly rapid release
reserve pool; mobilised by intense stimulation, slow release
What factors determine neurotransmitter release?
rate of cell firing
probability of neurotransmitter release
presence of auto receptors on axon terminals
What are the functions of auto receptors?
terminal; inhibit further neurotransmitter release
somatodendritic; slow the rate of cell firing
What happens during receptor binding?
NT rapidly diffuse across narrow synaptic cleft
binding to any receptors in the vicinity
often significant spillover into nearby synapses
What mechanisms are used during inactivation?
reuptake
enzyme degradation