E5 Electrical synaptic transmission (gap junctions)

Title

Gap junctions form direct intercellular channels (connections) that allow the passive flow of ionic current between two electrically coupled neurons, without chemical mediation or the synaptic delay of E04. The current that flows between the two cells is proportional to the transjunction potential difference (junction voltage), and the gap junction conductance can be fixed or depend on the junction voltage itself, in which case it adopts a sigmoid shape that can produce rectification. Each coupled cell follows its own membrane equation (inherited from E01), but now also includes the gap junction current as a coupling term, of opposite sign in each cell due to charge conservation. The coupling coefficient quantifies what fraction of a voltage disturbance in one cell is passively transmitted to the neighboring cell.

ID:4263