Primary changes of voltage responses during retention of associative learning.

Publisher Website
Google Scholar
Abstract
Type B photoreceptors in the eyes of the nudibranch mollusk Hermissenda crassicornis receive synaptic input from a vestibular organ known as the statocyst. By virtue of this synaptic convergence between the visual and statocyst pathways, repetitive presentation of light paired (but not unpaired) with rotation is accompanied by cumulative depolarization and enhancement of a long-lasting depolarization (LLD) of the type B membrane following light stimuli. This repetitive paired presentation of light and rotation also specifically produces a long-lasting behavioral change, which can serve as a model for vertebrate associative learning. Type B cells were isolated physically and electrically from the Hermissenda circumesophageal nervous system during the retention period of the associative learning. Two types of neural changes intrinsic to the type B soma were retained for 1 and 2 days following associative training. In the dark, input resistance increased, particularly when measured with injection of positive-current pulses. During light the steady-state depolarization increased and was followed at light offset by an increased LLD. Among the features of these changes described are a marked voltage dependence as well as a relationship to intracellular Ca2+. Evidence is discussed for a sequence of biophysical steps responsible for these changes of voltage responses and their role in causing retention of the associatively learned behavior.

This publication has 0 references indexed in Scilit: