Modification of adenosine modulation of acetylcholine release in the hippocampus of aged rats

Detalhes bibliográficos
Autor(a) principal: Rodrigues, Ricardo J.
Data de Publicação: 2008
Outros Autores: Canas, Paula M., Lopes, Luísa V., Oliveira, Catarina R., Cunha, Rodrigo A.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10316/4719
https://doi.org/10.1016/j.neurobiolaging.2007.03.025
Resumo: Adenosine is a neuromodulator acting through inhibitory A1 receptors (A1Rs) and facilitatory A2ARs. Since A2AR antagonists attenuate memory deficits in aged animals and memory deficits might involve a decreased cholinergic function, we investigated how aging affects the density and function of adenosine receptors in rat hippocampal cholinergic terminals. In young adult (2 months) rats, 64 and 36% of cholinergic terminals (immunopositive for vesicular ACh transporters) possessed A1Rs and A2ARs, respectively. In aged (24 months) rats, the percentage of cholinergic terminals with A1Rs was preserved, whereas that with A2ARs was larger (49%). In young adults adenosine only tonically inhibited ACh release through A1Rs, whereas in aged rats there was a greater A1R-mediated inhibition and a simultaneous A2AR-mediated facilitation of ACh release. Thus, the enhanced A2AR density and facilitation compensates for the greater tonic A1R modulation, preserving the global adenosine modulation of ACh release in aged rats. Furthermore, since A2AR antagonists inhibit ACh release, the beneficial effects of A2AR antagonists on memory in aged rats might not result from ACh release modulation.
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spelling Modification of adenosine modulation of acetylcholine release in the hippocampus of aged ratsAdenosineAcetylcholineNerve terminalsLocalizationDensityAdenosine is a neuromodulator acting through inhibitory A1 receptors (A1Rs) and facilitatory A2ARs. Since A2AR antagonists attenuate memory deficits in aged animals and memory deficits might involve a decreased cholinergic function, we investigated how aging affects the density and function of adenosine receptors in rat hippocampal cholinergic terminals. In young adult (2 months) rats, 64 and 36% of cholinergic terminals (immunopositive for vesicular ACh transporters) possessed A1Rs and A2ARs, respectively. In aged (24 months) rats, the percentage of cholinergic terminals with A1Rs was preserved, whereas that with A2ARs was larger (49%). In young adults adenosine only tonically inhibited ACh release through A1Rs, whereas in aged rats there was a greater A1R-mediated inhibition and a simultaneous A2AR-mediated facilitation of ACh release. Thus, the enhanced A2AR density and facilitation compensates for the greater tonic A1R modulation, preserving the global adenosine modulation of ACh release in aged rats. Furthermore, since A2AR antagonists inhibit ACh release, the beneficial effects of A2AR antagonists on memory in aged rats might not result from ACh release modulation.http://www.sciencedirect.com/science/article/B6T09-4NMTYT0-1/1/88b6c7dc830a530666753ca321c93da12008-09-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleaplication/PDFhttp://hdl.handle.net/10316/4719http://hdl.handle.net/10316/4719https://doi.org/10.1016/j.neurobiolaging.2007.03.025engNeurobiology of Aging. In Press, Corrected Proof:Rodrigues, Ricardo J.Canas, Paula M.Lopes, Luísa V.Oliveira, Catarina R.Cunha, Rodrigo A.info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2020-11-06T16:49:18Zoai:estudogeral.uc.pt:10316/4719Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:43:26.810994Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Modification of adenosine modulation of acetylcholine release in the hippocampus of aged rats
title Modification of adenosine modulation of acetylcholine release in the hippocampus of aged rats
spellingShingle Modification of adenosine modulation of acetylcholine release in the hippocampus of aged rats
Rodrigues, Ricardo J.
Adenosine
Acetylcholine
Nerve terminals
Localization
Density
title_short Modification of adenosine modulation of acetylcholine release in the hippocampus of aged rats
title_full Modification of adenosine modulation of acetylcholine release in the hippocampus of aged rats
title_fullStr Modification of adenosine modulation of acetylcholine release in the hippocampus of aged rats
title_full_unstemmed Modification of adenosine modulation of acetylcholine release in the hippocampus of aged rats
title_sort Modification of adenosine modulation of acetylcholine release in the hippocampus of aged rats
author Rodrigues, Ricardo J.
author_facet Rodrigues, Ricardo J.
Canas, Paula M.
Lopes, Luísa V.
Oliveira, Catarina R.
Cunha, Rodrigo A.
author_role author
author2 Canas, Paula M.
Lopes, Luísa V.
Oliveira, Catarina R.
Cunha, Rodrigo A.
author2_role author
author
author
author
dc.contributor.author.fl_str_mv Rodrigues, Ricardo J.
Canas, Paula M.
Lopes, Luísa V.
Oliveira, Catarina R.
Cunha, Rodrigo A.
dc.subject.por.fl_str_mv Adenosine
Acetylcholine
Nerve terminals
Localization
Density
topic Adenosine
Acetylcholine
Nerve terminals
Localization
Density
description Adenosine is a neuromodulator acting through inhibitory A1 receptors (A1Rs) and facilitatory A2ARs. Since A2AR antagonists attenuate memory deficits in aged animals and memory deficits might involve a decreased cholinergic function, we investigated how aging affects the density and function of adenosine receptors in rat hippocampal cholinergic terminals. In young adult (2 months) rats, 64 and 36% of cholinergic terminals (immunopositive for vesicular ACh transporters) possessed A1Rs and A2ARs, respectively. In aged (24 months) rats, the percentage of cholinergic terminals with A1Rs was preserved, whereas that with A2ARs was larger (49%). In young adults adenosine only tonically inhibited ACh release through A1Rs, whereas in aged rats there was a greater A1R-mediated inhibition and a simultaneous A2AR-mediated facilitation of ACh release. Thus, the enhanced A2AR density and facilitation compensates for the greater tonic A1R modulation, preserving the global adenosine modulation of ACh release in aged rats. Furthermore, since A2AR antagonists inhibit ACh release, the beneficial effects of A2AR antagonists on memory in aged rats might not result from ACh release modulation.
publishDate 2008
dc.date.none.fl_str_mv 2008-09-01
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10316/4719
http://hdl.handle.net/10316/4719
https://doi.org/10.1016/j.neurobiolaging.2007.03.025
url http://hdl.handle.net/10316/4719
https://doi.org/10.1016/j.neurobiolaging.2007.03.025
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Neurobiology of Aging. In Press, Corrected Proof:
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