NEUROPHYSIOLOGICAL ANALYSIS OF VISUO-VESTIBULAR CONDITIONING IN LYMNAEA STAGNALIS* SHORT COMMUNICATION

Lymnaea are capable of learning an association between light and rotation. The conditioning paradigm to produce this association and the unconditioned escape response are the same for both Lymnaea and Hermissenda, but the underlying neural mechanisms appear to differ between the two species due to differences in the organization and function of their visuo- and vestibular-sensory systems. The RPeD11 interneuron in Lymnaea controls withdrawal behavior. We analyzed the electrophysiologic characteristics of the RPeD11 and observed an increase in cell excitability; that is, spontaneous activity of the postsynaptic potential in the RpeD11 was increased in conditioned animals after learning acquisition.