Elsevier

Neuroscience Letters

Volume 230, Issue 3, 25 July 1997, Pages 179-182
Neuroscience Letters

Enhancement of an inhibitory input to the feeding central pattern generator in Lymnaea stagnalis during conditioned taste-aversion learning

https://doi.org/10.1016/S0304-3940(97)00507-7Get rights and content

Abstract

To study the neuronal mechanism of a conditioned taste-aversion (CTA) learning in the pond snail Lymnaea stagnalis, we examined the synaptic connection between the neuron 1 medial (N1M) cell and the cerebral giant cell (CGC), the former is an interneuron in central pattern generator for the feeding response and the latter is a regulatory neuron to the central pattern generator. Inhibitory postsynaptic potential (IPSP) which was evoked in the N1M cell by activation of the CGC was larger and lasted longer in the conditioned animal than that in the control animal. The electrical properties of the cell body of CGC and the responses of the CGC to the chemosensory inputs were not changed during the CTA learning. These results, together with the previous report indicating the existence of excitatory projection from the N1M cell to the feeding motoneuron, suggest that enhanced IPSP in the N1M cell may underlie the suppression of feeding responses in the Lymnaea CTA learning.

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Acknowledgements

We thank Professor W.P.M. Geraerts at Vrije Universiteit Amsterdam for kindly providing Lymnaea stagnalis and Professor A.G.M. Bulloch at University of Calgary for critically reading the manuscript. This work was supported by Grants-in-Aid (No. 08680858 and No. 08271202) from the Ministry of Education, Science, Sports and Culture of Japan and a grant from The Kurata Foundation to E.I.

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