Basal forebrain neurons modulate the synthesis and expression of neuropeptides in the rat suprachiasmatic nucleus

• Type: Article in International Scientific Journal
• Date: 2004

Authors

Madeira, MD (Author) FMUP; Pereira, PA (Author) FMUP; Silva, SM (Author) FMUP; Cadete Leite, A (Author) Other; Paula Barbosa, MM (Author) Other

Journal

Title: Neuroscience

Vol. 125

Pages: 889-901

ISSN: 0306-4522

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 32 Citations

Scopus - 34 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-000-D9E

DOI: 10.1016/j.neuroscience.2004.03.005

Abstract (EN): We tested the hypothesis that efferents from the nucleus basalis magnocellularis (NBM) play a direct role in the regulation of neuropeptide synthesis and expression by neurons of the rat suprachiasmatic nucleus (SCN). Adult male rats in which the NBM was destroyed with quinolinic acid, either unilaterally or bilaterally, were compared with rats injected with physiological saline and with control rats. The estimators used to assess the effects of cholinergic deafferentation on the neuroanatomy and neurochemistry of the SCN were the total number of SCN neurons, the total number and somatic size of SCN neurons producing vasopressin (VP) and vasoactive intestinal polypeptide (VIP), and the respective mRNA levels. Bilateral destruction of the NBM did not produce cell death in the SCN, but caused a marked reduction in the number and somatic size of SCN neurons expressing VP and VIP, and in the mRNA levels of these peptides. The decrease in the number of VP- and VIP-producing neurons provoked by unilateral lesions was less striking than that resulting from bilateral lesions. It was, however, statistically significant in the ipsilateral hemisphere, but not in the contralateral hemisphere. The results show that the reduction of cholinergic inputs to the SCN impairs the synthesis, and thereby decreases the expression of neuropeptides by SCN neurons, and that the extent of the decline correlates with the amount of cholinergic afferents destroyed. This supports the notion that acetylcholine plays an important, and direct role in the regulation of the metabolic activity of SCN neurons.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13