Influence of feeding status on neuronal activity in the hypothalamus during lipopolysaccharide-induced anorexia in rats

L. Gautron, R. Mingam, A. Moranis, C. Combe, S. Layé
Neuroscience. 2005-01-01; 134(3): 933-946
DOI: 10.1016/j.neuroscience.2005.03.063

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1. Neuroscience. 2005;134(3):933-46.

Influence of feeding status on neuronal activity in the hypothalamus during
lipopolysaccharide-induced anorexia in rats.

Gautron L(1), Mingam R, Moranis A, Combe C, Layé S.

Author information:
(1)Laboratoire des Régulations Neuroendocriniennes, EA 2972, Université Bordeaux
I, 33400 Talence, France.

Fasting attenuates disease-associated anorexia, but the mechanisms underlying
this effect are not well understood. In the present study, we investigated the
extent to which a 48 h fast alters hypothalamic neuronal activity in response to
the anorectic effects of lipopolysaccharide in rats. Male rats were fed ad
libitum or fasted, and were injected with i.p. saline or lipopolysaccharide (250
microg/kg). Immunohistochemistry for Fos protein was used to visualize neuronal
activity in response to lipopolysaccharide within selected hypothalamic feeding
regulatory nuclei. Additionally, food intake, body weight, plasma interleukin-1
and leptin levels, and the expression of mRNA for appetite-related neuropeptides
(neuropeptide Y, proopiomelanocortin and cocaine-amphetamine-regulated
transcript) were measured in a time-related manner. Our data show that the
pattern of lipopolysaccharide-induced Fos expression was similar in most
hypothalamic nuclei whatever the feeding status. However, we observed that
fasting significantly reduced lipopolysaccharide-induced Fos expression in the
paraventricular nucleus, in association with an attenuated
lipopolysaccharide-induced anorexia and body weight loss. Moreover,
lipopolysaccharide reduced fasting-induced Fos expression in the perifornical
area of the lateral hypothalamus. Lipopolysaccharide-induced circulating levels
of interleukin-1 were similar across feeding status. Finally, fasting, but not
lipopolysaccharide, affected circulating level of leptin and appetite-related
neuropeptides expression in the arcuate nucleus. Together, our data show that
fasting modulates lipopolysaccharide-induced anorexia and body weight loss in
association with neural changes in specific hypothalamic nuclei.

DOI: 10.1016/j.neuroscience.2005.03.063
PMID: 16039792 [Indexed for MEDLINE]

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