Structure and Function - Week 4 Neurotransmission Flashcards
What is neurotransmission? (2)
Communication within the nervous system and of the nervous system with other systems
Describe synaptic transmission (3)
AP arrives at pre synaptic terminal
Triggers entry of Ca2+ through voltage gated Ca2+ channel
Causes synaptic vesicles to release neurotransmitters across synaptic cleft
Neurotransmitter diffuse and bind to post synaptic receptors causing a post synaptic response
What could the post synaptic responses be? (4)
Depolarization
Hyperpolarization
Changes to biochemical cascade
Change to gene expression
What are the two types of transmission? (2)
Transmission can be extra-synaptic and non-synaptic too (volume transmission).
Describe electrical synapse (3)
Allow physical connection to exist between neurons through gap junctions
Gap junctions - made of connexin subunits (called connexon channels) - allow ions and other substances to transfer between 2 cells
Describe characteristics of chemical synapses (4)
Slow, has gain, diverse postsynaptic response, unidirectional release
Describe characteristics of electrical synapses (4)
Fast, lack gain, limited postsynaptic response, mostly bidirectional
Give examples of how could you assess electrical coupling between two neurons? (2)
Dual electrode recording
Cell traces
What are the 3 components of chemical synapses (3)
Presynaptic terminal
Synaptic cleft
Postsynaptic terminal
What is a bouton? (2)
Another name for axon terminals
Terminal enlargements on the axon where it forms a synapse
What are the different synapse locations (4)
Axon to soma
Axon to dendrite / spine
Axon to axon
Dendrite to dendrite
Describe axo-dendritic synapse (3)
Axon to dendritic shaft or spine
Spines are protrusions that increase surface area
Often excitatory
Describe Axo-Somatic synapse (3)
Axon to soma (cell body)
If synapse is at the axon hillock, large influence on firing
Often inhibitory
Describe Axo-Axonic synapse (3)
Modulatory - can be excitatory or inhibitory
Increased calcium current in presynaptic terminal = increase in transmitter release
Decreased calcium current in presynaptic terminal = decrease in transmitter release
What are the different types of vesicles? (2)
Small clear core vesicles
Large dense core vesicles