Stressor-induced alterations in serotonergic activity in an ... : NeuroReport (original) (raw)

Motivation, Emotion, Feeding, Drinking

Stressor-induced alterations in serotonergic activity in an animal model of depression

Connor, Thomas J.1,4; Song, Cai2; Leonard, Brian E.1; Anisman, Hymie2; Merali, Zul3

1Department of Pharmacology, National University of Ireland, Galway, Ireland

2Institute of Neuroscience, Carleton University, Ottawa, Ontario, Canada K1S 5B6

3School of Psychology and Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5

4Corresponding Author: Thomas J. Connor

ACKNOWLEDGEMENTS: This research was supported by a grant from the Medical Research Council of Canada to H.A. and Z.M. In addition, C.S. was supported by a fellowship from the Ontario Mental Health Foundation.

Received 12 November 1998; accepted 8 December 1998

Abstract

THE present study examined the effect of two neurogenic stressors (air puff and restraint) and a metabolic stressor (lipopolysaccharide; LPS 100 μg/kg, i.p.) on accumbal serotonergic neurotransmission in the olfactory bulbectomized (OB) rat model of depression. Both air puff and restraint stress caused greater increases in accumbal 5-HIAA in OB than in sham-operated rats. In contrast, bulbectomy resulted in a blunted serotonergic response to a challenge with LPS (a metabolic stressor). In addition, OB rats displayed significantly lower basal levels of 5-HIAA than sham-operated counterparts, a finding consistent with previous reports of the OB rat being a model of hyposerotonergic depression. The relevance of these findings to stressorprovoked depressive-like behaviors in the OB rat are discussed.