Neural control of behavioral responses in the nudibranch mollusc Phestilla sibogae.

Abstract

The tropical aeoliacean nudibranch Phestilla sibogae, has a number of large and reidentifiable neurons in its centrally located cerebral-pedal-pleural ganglion complex. In studies involving nearly intact animal preparations, neurons were identified which control specific movements of the dorsal cerata, the oral veil tentacles, and the margins of the foot. Responses of neurons to mechanical vibrations in the environment, and responses to light not mediated by the eyes are described. Finally, a pair of large cerebral neurons are identified that are superficially similar in structure, location, and function to the metacerebral giants found in several other opisthobranchs. These neurons are electrically coupled and control stereotyped movements of the mouth. These anatomical and neurophysiological features, when coupled with the fact that the generation time of Phestilla (30 days) is comparable to that of Drosophila suggests that this nudibranch may prove useful in combined studies of neurophysiology, behavior and genetics.