Effects of food deprivation on midbrain 5-HT(1A) autoreceptors in Lewis and SHR rats
Neuropharmacology. 1997-04-01; 36(4-5): 483-488
DOI: 10.1016/S0028-3908(97)00018-X
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Chaouloff F(1), Berton O, Aquerre S, Hay M, Mormede P.
Author information:
(1)INSERM CJF 94-05 INRA, Institut Francois Magendie, Bordeaux, France.
Food deprivation stimulates the activity of the hypothalamo-pituitary-adrenal
axis and brain serotonin (5-hydroxytryptamine, 5-HT) synthesis. Because midbrain
somato-dendritic 5-HT1A autoreceptors may obey homologous and heterologous (e.g.
by glucocorticoids) down-regulation, we have analyzed whether 24 hr of fasting
affects midbrain 5-HT1A receptor binding and sensitivity in Lewis and SHR rats
(i.e. strains that differ in behavioral/neuroendocrine responses to stressors).
Fasting affected neither [3H]8-hydroxy-2-(di-N-propylamino)tetralin
([3H]8-OH-DPAT) binding at 5-HT1A autoreceptors nor 8-OH-DPAT-induced inhibition
of midbrain 5-HT synthesis (an index of 5-HT1A autoreceptor sensitivity).
Because fasting increased 5-HT precursor (tryptophan) levels to similar extents
in the midbrains of saline- and 8-OH-DPAT-treated rats, we conclude that food
deprivation does not affect 5-HT1A autoreceptors. In turn, our results suggest
that the differential effects of 5-HT1A receptor agonists on food intake, in fed
and fasted rats may be independent from 5-HT1A autoreceptors.
DOI: 10.1016/s0028-3908(97)00018-x
PMID: 9225273