NS II Synapses Flashcards
whats the difference between a chemical and an electrical synapse
-chemical synapses involve NTs that are released from the presynaptic cell and bind receptors to excite, inhibit or modify post-synaptic cell
-electrical synapses use channel proteins
what determines the function in a chemical synapse
the receptor NOT the NT
what are the 3 types of chemical synapses
-axosomatic
-axodendritic
-axoaxonal
where do axosomatic synapses terminate and what type of synapse is it
on neuronal cell bodies and tend to be inhibitory
where do axodendritic synapses terminate and what type of synapse is it
terminate on dendrites or dendritic spines and tend to be excitatory
where do axoaxonal synapses terminate and what do they do
on an axon close to synaptic terminals and modulate the release of NTs
what are the 4 presynaptic events
-AP arrives at the synaptic terminal and causes depolarization
- Ca2+ channels open
-Calcium enters synaptic terminal
-exocytosis of vesicles filled with NT
what determines the amount of NT released
the amount of calcium
what events contribute to synaptic delay
calcium entry for exocytosis, presynaptic NT release, diffusion in the synaptic cleft, and post synaptic receptor activation
what are the different classes of NTs
-small molecules
-neuropeptides
where does processing of small molecule NTs occur? neuropeptides?
small molecule: in the axon terminal
neuropeptides: cell body and transported down the axon
whats the main difference between small molecule NTs and neuropeptides
small molecule NTs are fast acting and acute, neuropeptides are slower, more potent and more prolonged
what would cause an EPSP
-opening Na+ channels
-closing K+ and/or Cl- channels
what would cause an IPSP
-opening Cl- channels
-increased K+ conductance
what is spatial summation
simultaneous EPSPs or IPSPs from multiple pre-synaptic neurons
