STRUCTURAL REORGANIZATION IN THE SUPRAOPTIC NUCLEUS OF WITHDRAWN RATS FOLLOWING LONG-TERM ALCOHOL-CONSUMPTION

• Type: Article in International Scientific Journal
• Date: 1995

Authors

SOUSA, N (Author) Other; MADEIRA, MD (Author) FMUP; RUELA, C (Author) Other; PAULABARBOSA, MM (Author) Other

Journal

Title: Alcoholism: Clinical and Experimental Research

Vol. 19

Pages: 879-885

ISSN: 0145-6008

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 13 Citations

Scopus - 14 Citations

Scientific classification

FOS: Medical and Health sciences > Health sciences

Other information

Authenticus ID: P-001-GG3

DOI: 10.1111/j.1530-0277.1995.tb00962.x

Abstract (EN): We have recently shown in the supraoptic nucleus (SON) of the rat that prolonged ethanol consumption induces cell degeneration and enlargement of the surviving neurons and of their subcellular organelles. We analyzed the SON of withdrawn rats to evaluate whether it displays any evidence of morphological reorganization following abstinence from ethanol, inasmuch as in this condition the ethanol-induced changes in the plasma levels of neurohormones and plasma osmolality are no longer detectable. A group of 18-month-old withdrawn rats was compared with age-matched, pair-fed control and ethanol-treated rats. To differentiate between the effects of withdrawal and the effects of rehydration, a group of 18-month-old rehydrated rats was also included in this study and compared with age-matched, pair-fed control and dehydrated rats. We estimated the volume of SON, and the total number and mean volume of its neurons. The cross-sectional areas of the vasopressinergic and oxytocinergic populations were also evaluated. At the ultrastructural level, we determined the volumes and surface areas of the rough endoplasmic reticulum and Golgi apparatus, and the volumes of neurosecretory granules and nucleoli. In withdrawn animals, the total number of SON neurons was smaller than in controls, although the neuronal volume was greater. The number of SON neurons did not differ between withdrawn and ethanol-treated rats, despite the reduced volume of SON in the former animals. The decrease of SON volume correlated with and was caused by a reduction in the volume of SON neurons and in the size of the organelles involved in neurohormone synthesis. Thus, withdrawal from ethanol stops the ethanol-induced neuronal degeneration of the SON and partially reverses the ethanol-induced enlargement of SON neurons and their organelles. We suggest that the larger volume of SON neurons in withdrawn animals relative to controls represents a compensatory mechanism, triggered by the reduced number of neurons, to allow the maintenance of adequate levels of circulating neurohormones.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7