Purinoceptors and synaptic plasticity

• Tipo: Artigo em Revista Científica Internacional
• Data: 1996

Autores

Ribeiro, JA (Autor) Outra; deMendonca, A (Autor) Outra; Paulo Correia de Sá (Autor) Outra; Cunha, RA (Autor) Outra; Sebastiao, AM (Autor) Outra

Revista

Título: Drug Development Research

Vol. 39

Páginas: 353-360

ISSN: 0272-4391

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 4 Citações

Scopus - 4 Citações

Outras Informações

ID Authenticus: P-001-DDW

DOI: 10.1002/(sici)1098-2299(199611/12)39:3/4<353::aid-ddr16>3.0.co;2-2

Abstract (EN): Adenosine is considered an important modulator of the nervous system acting at pre-, post-, and nonsynaptic levels. In models (e.g. the rat neuromuscular junction) where adenosine has only presynaptic (inhibitory, which are A(1)-receptor mediated; and excitatory, which are A(2A)-receptor mediated) effects, the action of adenosine on transmitter release depends on the intensity of stimulation. It is inhibitory with low frequencies of stimulation and excitatory with high frequencies of stimulation. This finding suggests that the presynaptic adenosine A(1)/A(2A) receptor activation balance depends on the pattern of stimulation. At the rat hippocampal slices, endogenous adenosine inhibits the neurophysiological basis of learning and memory: long-term potentiation (LTP), long-term depression (LTD), and depotentiation. Adenosine A(2A) agonists facilitate LTP. Because the adenosine analogue 2-chloroadenosine in low concentrations (100 nM) inhibits N-methyl-D-aspartate (NMDA) currents in pyramidal cells, it is likely that the inhibitory effects of adenosine on LTP and LTD/depotentiation are a consequence of its ability to inhibit NMDA currents. The modulatory actions of adenosine on synaptic plasticity support the role of this nucleoside in cognition, and therefore, A(1) antagonists and A(2A) agonists could be considered as potential cognitive enhancers. The adaptation of adenosine to activate presynaptic Al or A(2A) receptors at low or high frequencies of stimulation anticipates the potential interest of A(1) antagonists and A(2A) agonists as enhancers of neuromuscular transmission. (C) 1997 Wiley-Liss, Inc.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8