Cargando…

Ventral Tegmental Area Inactivation Suppresses the Expression of CA1 Long Term Potentiation in Anesthetized Rat

The hippocampus receives dopaminergic projections from the ventral tegmental area (VTA). Modulatory effect of dopamine on hippocampal long term potentiation (LTP) has been studied before, but there are conflicting results and some limitations in previous reports. Most of these studies show a signifi...

Descripción completa

Detalles Bibliográficos
Autores principales: Ghanbarian, Elham, Motamedi, Fereshteh
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3594179/
https://www.ncbi.nlm.nih.gov/pubmed/23536829
http://dx.doi.org/10.1371/journal.pone.0058844
_version_ 1782262297352208384
author Ghanbarian, Elham
Motamedi, Fereshteh
author_facet Ghanbarian, Elham
Motamedi, Fereshteh
author_sort Ghanbarian, Elham
collection PubMed
description The hippocampus receives dopaminergic projections from the ventral tegmental area (VTA). Modulatory effect of dopamine on hippocampal long term potentiation (LTP) has been studied before, but there are conflicting results and some limitations in previous reports. Most of these studies show a significant effect of dopamine on the late phase of LTP in CA1 area of the hippocampus, while few reports show an effect on the early phase. Moreover, they generally manipulated dopamine receptors in the hippocampus and there are few studies investigating influence of the VTA neural activity on hippocampal LTP in the intact brain. Besides, VTA neurons contain other neurotransmitters such as glutamate and GABA that may modify the net effect of dopamine. In this study we examined the effect of VTA reversible inactivation on the induction and maintenance of early LTP in the CA1 area of anesthetized rats, and also on different phases of learning of a passive avoidance (PA) task. We found that inactivation of the VTA by lidocaine had no effect on CA1 LTP induction and paired-pulse facilitation, but its inactivation immediately after tetanic stimulation transiently suppressed the expression of LTP. Blockade of the VTA 20 min after tetanic stimulation had no effect on the magnitude of LTP. Moreover, VTA inactivation immediately after training impaired memory in the passive avoidance task, while its blockade before or 20 min after training produced no memory deficit. It can be concluded that VTA activity has no effect on CA1 LTP induction and acquisition of PA task, but involves in the expression of LTP and PA memory consolidation.
format Online
Article
Text
id pubmed-3594179
institution National Center for Biotechnology Information
language English
publishDate 2013
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-35941792013-03-27 Ventral Tegmental Area Inactivation Suppresses the Expression of CA1 Long Term Potentiation in Anesthetized Rat Ghanbarian, Elham Motamedi, Fereshteh PLoS One Research Article The hippocampus receives dopaminergic projections from the ventral tegmental area (VTA). Modulatory effect of dopamine on hippocampal long term potentiation (LTP) has been studied before, but there are conflicting results and some limitations in previous reports. Most of these studies show a significant effect of dopamine on the late phase of LTP in CA1 area of the hippocampus, while few reports show an effect on the early phase. Moreover, they generally manipulated dopamine receptors in the hippocampus and there are few studies investigating influence of the VTA neural activity on hippocampal LTP in the intact brain. Besides, VTA neurons contain other neurotransmitters such as glutamate and GABA that may modify the net effect of dopamine. In this study we examined the effect of VTA reversible inactivation on the induction and maintenance of early LTP in the CA1 area of anesthetized rats, and also on different phases of learning of a passive avoidance (PA) task. We found that inactivation of the VTA by lidocaine had no effect on CA1 LTP induction and paired-pulse facilitation, but its inactivation immediately after tetanic stimulation transiently suppressed the expression of LTP. Blockade of the VTA 20 min after tetanic stimulation had no effect on the magnitude of LTP. Moreover, VTA inactivation immediately after training impaired memory in the passive avoidance task, while its blockade before or 20 min after training produced no memory deficit. It can be concluded that VTA activity has no effect on CA1 LTP induction and acquisition of PA task, but involves in the expression of LTP and PA memory consolidation. Public Library of Science 2013-03-11 /pmc/articles/PMC3594179/ /pubmed/23536829 http://dx.doi.org/10.1371/journal.pone.0058844 Text en © 2013 Ghanbarian, Motamedi 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
Ghanbarian, Elham
Motamedi, Fereshteh
Ventral Tegmental Area Inactivation Suppresses the Expression of CA1 Long Term Potentiation in Anesthetized Rat
title Ventral Tegmental Area Inactivation Suppresses the Expression of CA1 Long Term Potentiation in Anesthetized Rat
title_full Ventral Tegmental Area Inactivation Suppresses the Expression of CA1 Long Term Potentiation in Anesthetized Rat
title_fullStr Ventral Tegmental Area Inactivation Suppresses the Expression of CA1 Long Term Potentiation in Anesthetized Rat
title_full_unstemmed Ventral Tegmental Area Inactivation Suppresses the Expression of CA1 Long Term Potentiation in Anesthetized Rat
title_short Ventral Tegmental Area Inactivation Suppresses the Expression of CA1 Long Term Potentiation in Anesthetized Rat
title_sort ventral tegmental area inactivation suppresses the expression of ca1 long term potentiation in anesthetized rat
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3594179/
https://www.ncbi.nlm.nih.gov/pubmed/23536829
http://dx.doi.org/10.1371/journal.pone.0058844
work_keys_str_mv AT ghanbarianelham ventraltegmentalareainactivationsuppressestheexpressionofca1longtermpotentiationinanesthetizedrat
AT motamedifereshteh ventraltegmentalareainactivationsuppressestheexpressionofca1longtermpotentiationinanesthetizedrat