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Hippocampal cholinergic receptors and the mTOR participation in fear-motivated inhibitory avoidance extinction memory.
Rosa, Jessica; de Carvalho Myskiw, Jociane; Fiorenza, Natalia Gindri; Furini, Cristiane Regina Guerino; Sapiras, Gerson Guilherme; Izquierdo, Ivan.
Afiliação
  • Rosa J; Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; Department of Pharmacology, School of Medicine of Ribeirao Preto, University of Sao Paulo (USP), Bandeirantes 3900, 14049-900 
  • de Carvalho Myskiw J; Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Federal University of Rio de Jan
  • Fiorenza NG; Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; Oswaldo Cruz Foundation (FIOCRUZ), Branch Ceara, 60760-000 Eusebio, CE, Brazil.
  • Furini CRG; Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Federal University of Rio de Jan
  • Sapiras GG; Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; Clinical Hospital of Passo Fundo (HCPF), Tiradentes 295, 99010-260 Passo Fundo, RS, Brazil.
  • Izquierdo I; Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Federal University of Rio de Jan
Behav Brain Res ; 437: 114129, 2023 02 02.
Article em En | MEDLINE | ID: mdl-36179804
ABSTRACT
Evidence has demonstrated the hippocampal cholinergic system and the mammalian target of rapamycin (mTOR) participation during the memory formation of aversive events. This study assessed the role of these systems in the hippocampus for the extinction memory process by submitting male Wistar rats to fear-motivated step-down inhibitory avoidance (IA). The post-extinction session administration of the nicotinic and muscarinic cholinergic receptor antagonists, mecamylamine and scopolamine, respectively, both at doses of 2 µg/µl/side, and rapamycin, an mTOR inhibitor (0.02 µg/µl/side), into the CA1 region of the dorsal hippocampus, impaired the IA extinction memory. Furthermore, the nicotinic and muscarinic cholinergic receptor agonists, nicotine and muscarine, respectively, had a dose-dependent effect on the IA extinction memory when administered intra-CA1, immediately after the extinction session. Nicotine (0.6 µg/µl/side) and muscarine (0.02 µg/µl/side), respectively, had no effect, while the higher doses (6 and 2 µg/µl/side, respectively) impaired the IA extinction memory. Interestingly, the co-administration of muscarine at the lower dose blocked the impairment that was induced by rapamycin. This effect was not observed when nicotine at the lower dose was co-administered. These results have demonstrated the participation of the cholinergic receptors and mTOR in the hippocampus for IA extinction, and that the cholinergic agonists had a dose-dependent effect on the IA extinction memory. This study provides insights related to the behavioural aspects and the neurobiological properties underlying the early stage of fear-motivated IA extinction memory consolidation and suggests that there is hippocampal muscarinic receptor participation independent of mTOR in this memory process.
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Texto completo: 1 Base de dados: MEDLINE Assunto principal: Aprendizagem da Esquiva / Receptores Colinérgicos / Extinção Psicológica / Medo / Serina-Treonina Quinases TOR / Hipocampo / Memória Limite: Animals Idioma: En Ano de publicação: 2023 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Aprendizagem da Esquiva / Receptores Colinérgicos / Extinção Psicológica / Medo / Serina-Treonina Quinases TOR / Hipocampo / Memória Limite: Animals Idioma: En Ano de publicação: 2023 Tipo de documento: Article