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Memory Trace in Feeding Neural Circuitry Underlying Conditioned Taste Aversion in Lymnaea

BACKGROUND: The pond snail Lymnaea stagnalis can maintain a conditioned taste aversion (CTA) as a long-term memory. Previous studies have shown that the inhibitory postsynaptic potential (IPSP) evoked in the neuron 1 medial (N1M) cell by activation of the cerebral giant cell (CGC) in taste aversion-...

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Autores principales: Ito, Etsuro, Otsuka, Emi, Hama, Noriyuki, Aonuma, Hitoshi, Okada, Ryuichi, Hatakeyama, Dai, Fujito, Yutaka, Kobayashi, Suguru
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3416747/
https://www.ncbi.nlm.nih.gov/pubmed/22900097
http://dx.doi.org/10.1371/journal.pone.0043151
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author Ito, Etsuro
Otsuka, Emi
Hama, Noriyuki
Aonuma, Hitoshi
Okada, Ryuichi
Hatakeyama, Dai
Fujito, Yutaka
Kobayashi, Suguru
author_facet Ito, Etsuro
Otsuka, Emi
Hama, Noriyuki
Aonuma, Hitoshi
Okada, Ryuichi
Hatakeyama, Dai
Fujito, Yutaka
Kobayashi, Suguru
author_sort Ito, Etsuro
collection PubMed
description BACKGROUND: The pond snail Lymnaea stagnalis can maintain a conditioned taste aversion (CTA) as a long-term memory. Previous studies have shown that the inhibitory postsynaptic potential (IPSP) evoked in the neuron 1 medial (N1M) cell by activation of the cerebral giant cell (CGC) in taste aversion-trained snails was larger and lasted longer than that in control snails. The N1M cell is one of the interneurons in the feeding central pattern generator (CPG), and the CGC is a key regulatory neuron for the feeding CPG. METHODOLOGY/PRINCIPLE FINDINGS: Previous studies have suggested that the neural circuit between the CGC and the N1M cell consists of two synaptic connections: (1) the excitatory connection from the CGC to the neuron 3 tonic (N3t) cell and (2) the inhibitory connection from the N3t cell to the N1M cell. However, because the N3t cell is too small to access consistently by electrophysiological methods, in the present study the synaptic inputs from the CGC to the N3t cell and those from the N3t cell to the N1M cell were monitored as the monosynaptic excitatory postsynaptic potential (EPSP) recorded in the large B1 and B3 motor neurons, respectively. The evoked monosynaptic EPSPs of the B1 motor neurons in the brains isolated from the taste aversion-trained snails were identical to those in the control snails, whereas the spontaneous monosynaptic EPSPs of the B3 motor neurons were significantly enlarged. CONCLUSION/SIGNIFICANCE: These results suggest that, after taste aversion training, the monosynaptic inputs from the N3t cell to the following neurons including the N1M cell are specifically facilitated. That is, one of the memory traces for taste aversion remains as an increase in neurotransmitter released from the N3t cell. We thus conclude that the N3t cell suppresses the N1M cell in the feeding CPG, in response to the conditioned stimulus in Lymnaea CTA.
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spelling pubmed-34167472012-08-16 Memory Trace in Feeding Neural Circuitry Underlying Conditioned Taste Aversion in Lymnaea Ito, Etsuro Otsuka, Emi Hama, Noriyuki Aonuma, Hitoshi Okada, Ryuichi Hatakeyama, Dai Fujito, Yutaka Kobayashi, Suguru PLoS One Research Article BACKGROUND: The pond snail Lymnaea stagnalis can maintain a conditioned taste aversion (CTA) as a long-term memory. Previous studies have shown that the inhibitory postsynaptic potential (IPSP) evoked in the neuron 1 medial (N1M) cell by activation of the cerebral giant cell (CGC) in taste aversion-trained snails was larger and lasted longer than that in control snails. The N1M cell is one of the interneurons in the feeding central pattern generator (CPG), and the CGC is a key regulatory neuron for the feeding CPG. METHODOLOGY/PRINCIPLE FINDINGS: Previous studies have suggested that the neural circuit between the CGC and the N1M cell consists of two synaptic connections: (1) the excitatory connection from the CGC to the neuron 3 tonic (N3t) cell and (2) the inhibitory connection from the N3t cell to the N1M cell. However, because the N3t cell is too small to access consistently by electrophysiological methods, in the present study the synaptic inputs from the CGC to the N3t cell and those from the N3t cell to the N1M cell were monitored as the monosynaptic excitatory postsynaptic potential (EPSP) recorded in the large B1 and B3 motor neurons, respectively. The evoked monosynaptic EPSPs of the B1 motor neurons in the brains isolated from the taste aversion-trained snails were identical to those in the control snails, whereas the spontaneous monosynaptic EPSPs of the B3 motor neurons were significantly enlarged. CONCLUSION/SIGNIFICANCE: These results suggest that, after taste aversion training, the monosynaptic inputs from the N3t cell to the following neurons including the N1M cell are specifically facilitated. That is, one of the memory traces for taste aversion remains as an increase in neurotransmitter released from the N3t cell. We thus conclude that the N3t cell suppresses the N1M cell in the feeding CPG, in response to the conditioned stimulus in Lymnaea CTA. Public Library of Science 2012-08-10 /pmc/articles/PMC3416747/ /pubmed/22900097 http://dx.doi.org/10.1371/journal.pone.0043151 Text en © 2012 Ito et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Ito, Etsuro
Otsuka, Emi
Hama, Noriyuki
Aonuma, Hitoshi
Okada, Ryuichi
Hatakeyama, Dai
Fujito, Yutaka
Kobayashi, Suguru
Memory Trace in Feeding Neural Circuitry Underlying Conditioned Taste Aversion in Lymnaea
title Memory Trace in Feeding Neural Circuitry Underlying Conditioned Taste Aversion in Lymnaea
title_full Memory Trace in Feeding Neural Circuitry Underlying Conditioned Taste Aversion in Lymnaea
title_fullStr Memory Trace in Feeding Neural Circuitry Underlying Conditioned Taste Aversion in Lymnaea
title_full_unstemmed Memory Trace in Feeding Neural Circuitry Underlying Conditioned Taste Aversion in Lymnaea
title_short Memory Trace in Feeding Neural Circuitry Underlying Conditioned Taste Aversion in Lymnaea
title_sort memory trace in feeding neural circuitry underlying conditioned taste aversion in lymnaea
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3416747/
https://www.ncbi.nlm.nih.gov/pubmed/22900097
http://dx.doi.org/10.1371/journal.pone.0043151
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