CELLULAR STUDIES OF PERIPHERAL NEURONS IN SIPHON SKIN OF APLYSIA-CALIFORNICA

To account for the similarity in the kinetics of habituation between the central and peripheral components of siphon withdrawal, we have tested the idea that each centrally located mechanoreceptor sensory neuron sends two branches to siphon motor neurons; one to centrally located siphon motor neurons and a collateral branch that remains in the periphery and innervates the peripheral siphon motor neurons. We have found a group of peripheral siphon motor neurons and tested the connection onto these cells by central mechanoreceptors. In addition, we have defined by various electrophysiological and morphological criteria two general classes of peripheral neurons that lie along the course of the siphon nerve.