Nerve growth factor restores mRNA levels and the expression of neuropeptides in the suprachiasmatic nucleus of rats submitted to chronic ethanol treatment and withdrawal

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

Paula Barbosa, MM (Autor) Outra; Silva, SM (Autor) FMUP; Andrade, JP (Autor) FMUP; Cadete Leite, A (Autor) Outra; Madeira, MD (Autor) FMUP

Revista

Título: Journal of Neurocytology

Vol. 30

Páginas: 195-207

ISSN: 0300-4864

Editora: Kluwer Academic Publishers

Indexação

ISI Web of Knowledge - 21 Citações

Scopus - 21 Citações

Classificação Científica

FOS: Ciências médicas e da saúde > Medicina básica

Outras Informações

ID Authenticus: P-000-W9K

DOI: 10.1023/a:1012745606781

Abstract (EN): Chronic ethanol treatment and withdrawal from alcohol decrease the synthesis and expression of neuropeptides in the hypothalamic suprachiasmatic nucleus. Given the existing evidence that neurotrophins modulate the synthesis and expression of neurotransmitters/neuromodulators in the mature brain, we have hypothesized that such alterations might result from the reduced biological activity or brain content of neurotrophic factors. To test this possibility, nerve growth factor (NGF) was delivered intraventricularly, over a 4-week period, to rats submitted to ethanol treatment for 6 months and to withdrawn rats. Vasopressin (AVP) and vasoactive intestinal polypeptide (VIP), and the respective mRNAs were detected by immunocytochemistry and in situ hybridization histochemistry, and their levels estimated using stereological methods and densitometry. In ethanol-treated and withdrawn rats, NGF produced increases in the number of AVP- and VIP-immunostained neurons to values identical to those of controls. Corresponding variations were detected in AVP and VIP mRNA levels, which indicates that NGF restored the expression of AVP and VIP by enhancing neuropeptide synthesis. These findings show that NGF can correct the changes induced by chronic ethanol treatment and withdrawal in the gene expression and protein content of the neuropeptides synthesized by suprachiasmatic neurons. They also reveal that NGF plays an important role in the maintenance of the neurochemical phenotype of the suprachiasmatic nucleus in the adult rat. Because suprachiasmatic neurons do not express trkA, NGF might have exerted its effects either through direct signalling of suprachiasmatic neurons via p75(NTR) activation or, indirectly, by enhancing the activity of the cholinergic and/or glutamatergic afferents to the suprachiasmatic nucleus, or both.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 13