chapter 1 - structure of chemical synapses

Question 1

1.1. [structure of chemical synapses] Name or indicate structures on images of synapses

Answer 1

take out image and do that

Question 2

1.2. [structure of chemical synapses] How are synapses classified based on (a) type of NT, (b) postsynaptic receptors, postsynaptic responses, and (c) ultrastructural morphological features

Answer 2

a. chemical synapses can be excitatory (e.g. glutamate), inhibitory (e.g. gaba or glycine) or neuromodulatory (e.g. monoamines).
Furthermore, synaptic diversity is also based on their location (central vs peripheral) - for example the neuromuscular junction, the neuro-endocrine junction)
b. Excitatory synapses depolarize the post synapse (ampa and nmda receptors), while inhibitory synapses hyperpolarize it. As for neuromodulatory synapses they do not have ionotropic receptors, they induce biochemical changes in the postsynapse
c. The ultrastructural morphological features of synapses include: central synapse (where the axon of the presynapse contacts the dendrite of a postsynaptic neuron), type 1 (symmetrical) - usually excitatory and on dendrides and dendritic spines, type 2 (asymmetrical) usually inhibitory and on soma and axonal initial segment . On the presynapse plasma membrane we can find the active zone, a specialized region where vesicles are docked and primed for release, the AZ is aligned with the post synaptic density. The molecular composition of PSD includes: 1. neurotransmitter receptors 2. transsynaptic adhesion molecules 3. scaffolding molecules 4. signal transduction molecules.