Electrical Synaptic Transmission

Electrical synapse(ES) can be either unidirectional or bidirectional

Example of Unidirection ES: giant synapse in the cray fish abdominal nerve cord and ganglion
Presynaptic neuron: lateral giant fiber
postsynaptic neuron: gaint motor fiber

current pulse injection to presynaptic neuron--->AP in presynaptic neuron---> postsynaptic AP (almost synchronous)

반대로 postsynaptic neuron에 current injection---> no response in the presynaptic neuron
따라서 transmission is unidirectional (rectifying synapse)

current injection을 threshold보다 적게 줘서 depolarize: pre---> post로 current flow, post--X--> pre

대부분의 electrical synapse는 bidirectional current flow (nonrectifying synapse)

Electrical transmission allows for rapid and synchronous firing of interconnected cells

예: tail-flip escape response of glodfish: sensory neurons make electrical synapses with motor neurons---> fast escape behavior

marine snail Aplysia: group의 motor neurons: high threshold, when stimulated enough---> explosive sinchonous firing
어떤 어류의 saccadic eye movement에서도

transmission of developmental or regulatory signals between cells
Electrical synapse의 gap junction diameter가 크기 때문에 MW 1000 정도의 물질이동 가능 (cAMP, small peptides)