E4 Chemical synaptic transmission

Title

Chemical synaptic transmission converts the presynaptic action potential (E2) into the postsynaptic neuron input through Ca2+-dependent neurotransmitter release, diffusion into the synaptic cleft, and activation of postsynaptic receptors. The influx of Ca2+ into the presynaptic terminal highly cooperatively controls the release probability and the number of vesicles released. The released neurotransmitter binds reversibly to postsynaptic receptors, whose occupancy follows two-state kinetics; In ionotropic receptors this union opens a channel whose resulting conductance is usually modeled with a biexponential form (rapid rise, slower decay), generating a postsynaptic current that depolarizes or hyperpolarizes the membrane according to the reversal potential of the channel. In the short term, synaptic efficacy can be facilitated or depressed depending on the recent history of presynaptic activity, a phenomenon captured by Tsodyks-Markram-type models of synaptic resources. The variables V_m, C_m, g, E and R_m reuse the E1-E3 notation.

ID:4262