NROB60H3 Chapter Notes - Chapter 5: Secretion, Synaptic Vesicle, Inhibitory Postsynaptic Potential
Document Summary
The process of information transfer at a synapse is called synaptic transmission: electrical synapses are common in brains of invertebrates and vertebrates. Electrical synapses are relatively simple in structure and junction, and they allow the direct transfer of ionic current from one cell to the next: occur at gap junctions. When gap junctions interconnect neurons they can function as electrical synapses. The narrow gap (3nm) is spanned by clusters of special proteins called connexins. Six connexin subunits combine to form a channel called a connexon. Two connexions meet and combine to form a gap junction: this channel allows ions to pass directly from the cytoplasm of one. Most gap junctions allow ionic current to pass equally well in both directions cell to the cytoplasm of the other: electrical synapses are bidirectional. Because electrical current can pass through these channels, cells connected by gap junction are said to be electrically coupled. Transmission at electrical synapses is very fast.
