ELECTROTONIC COUPLING BETWEEN NEUROSECRETORY-CELLS IN THE CRAYFISH EYESTALK

Electrical coupling is described among neurosecretory cells in the cra yfish X organ. By simultaneous impalements from pairs of neurons, only 30% were found to be coupled. All of them showed non-rectifying junct ions. In all cases, electrical coupling corresponded to dye-coupling, as explored with intracellular injection of Lucifer yellow to one of t he recorded cells. Some neurons were coupled to more than one neighbou r. From dye fills it was apparent that the coupling site could be loca ted far away from the cell body, immediately before the axonal branchi ngs in the neuropile. The input resistance of the coupled neurons was consistently lower (24 +/- 16 MOMEGA) than that of the non-coupled neu rons (58 +/- 18 MOMEGA). Synchronous synaptic activity was commonly re corded from coupled neurons, thus suggesting a functional significance of coupling in the integration of neurosecretory activity.