2.5: Neurotransmitters & pharmacology Flashcards
What is synaptic transmission?
Information transfer across synapse requiring release of neurotransmitters and their interaction with postsynaptic receptors
List 4 characteristics of synaptic transmission
Rapid timescale
Diversity
Plasticity
Learning and memory
4 basic structures of neurones
Dendrites
Soma
Axon
Synaptic terminal
Purpose of spines present on surface of dendrites
Protein molecules that increase the surface area for information reception
What neuronal structure integrates all information coming into a neurone
Soma (cell body)
3 steps that occur when a dendrite of one neurone receives an electrical impulse form another neurone
Information reception at dendrites
Integration (occurs at soma)
Rapid transfer (AP) - impulse passed along axon towards synaptic terminals
What type of neurotransmission occurs at the synapse
Chemical neurotransmission
What structures is neurotransmission restricted to?
Synapses
3 things synapse consists of
Presynaptic nerve ending/terminal
Gap(synaptic cleft) ~ 20-100nm
Postsynaptic regions (dendrite or cell soma)
3 stages of synaptic transmission
Biosynthesis, packaging and release of neurotransmitter stored in vesicles
Receptor action- activation of post-synaptic receptors
Inactivation - NT inactivated once it’s activated receptors on post synaptic terminal
3 types of molecules that can be neurotransmitters + examples
Amino acids - glutamate, gamma-aminobutyric acid (GABA)
Amines - noradrenaline and dopamine
Neuropeptices -opioid peptides
Single-most important excitatory neurotransmitter in the brain
Glutamate
Single-most important inhibitory neurotransmitter in the brain
GABA
Where is glycine most active (2)
Is glycine excitatory or inhibitory?
Spinal cord and brain stem
Inhibitory
2 methods by which neurotransmitters are returned to the pre-synaptic terminal
Re-uptake via protein transport channel
Enzymatic degradation within synaptic cleft
What is the source of neurotransmitter
Synaptic vesicles
Outline process of neurotransmitter release
Membrane depolarisation lead to opening of Ca2+ channels
Ca2+ influx leading to docking of synaptic vesicles onto pre-synaptic membrane
Neurotransmitter released by exocytosis in synaptic cleft
Vesicle buds off and recycles forming new vesicles that can be reused
2 things required for neurotransmitter release
Calcium influx
Rapid transduction