GAP-JUNCTIONS AS ELECTRICAL SYNAPSES

Gap junctions are the morphological substrate of one class of electric al synapse. The history of the debate on electrical vs. chemical trans mission is instructive. One lesson is that Occam's razor sometimes cut s too deep; the nervous system does its operations in a number of diff erent ways and a unitarian approach can lead one astray. Electrical sy napses can do many things that chemical synapses can do, and do them j ust as slowly. More intriguing are the modulatory actions that chemica l synapses can have on electrical synapses. Voltage dependence provide s an important window on structure function relations of the connexins , even where the dependence may have no physiological role. The new mo lecular approaches will greatly advance our knowledge of where gap jun ctions occur and permit experimental manipulation with high specificit y.