What is the advantage of chemical transmission
Greater control of synaptic strength
What is the major stimulatory neurotransmitter
Glutamate
What is the major inhibitory neurotransmitter
GABA
What are the 3 components of a chemical synapse
Tripartite synapse
- presynaptic nerve
- postsynaptic cell
- astrocytes
GFAP
A protein specific to astrocytes
How are neurons and astrocytes positioned
- closely associated
- wrap around dendrites
How big are SSVs
50nm diameter
How do SSVs look under EMs
Electron lucent
Where are SSVs positioned
Membrane bound
What do SSVs contain
Classical neurotransmitters eg.
- GABA
- Glutamate
- Glycine
Where are SSVs loaded
At synapses
Why are SSVs loaded at axon terminals
Allows fast recycling
How big are LDCV
100nm
How do LDCVs look under EM
Electron dense
What do LDCV contain
- hormones
- neuropeptides
- neurotrophins
How are LDCVs filled
Loaded via the secretory pathway
Where are LDCV neuropeptides synthesised and modified
rER and Golgi Apparatus
What is packaged into LDCVs
Pro-peptides and modifying enzymes
Where are LDCVs primarily located
- PNS
- hypothalamus
- neurosecretory cells
- neuroendocrine cells
Neurosecretory cells
Secrete their products into the pituitary portal vessels
Neuroendocrine cells
Receive neuronal input and release hormones into the blood stream
What percentage of vesicles are LDCV
1~2% of vesicles
Are LDCVs released fast or slowly
Slow release
Where are LDCVs located
Can be inside or outside of the active zones
