Effects of preshock experience on enhancement of rat brain noradrenaline turnover induced by psychological stress.
Pharmacol Biochem Behav
; 24(1): 115-9, 1986 Jan.
Article
em En
| MEDLINE
| ID: mdl-3945655
ABSTRACT
The present study examined alterations of brain noradrenaline (NA) turnover as a function of preshock and psychological stress treatments, by measuring contents of NA metabolite, 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPG-SO4), in discrete brain regions of male Wistar rats. Psychological stress induced by exposing to the sight, sound and odor of other rats being shocked produced higher levels of MHPG-SO4 in the hypothalamus, amygdala and locus coeruleus (LC) region, as well as higher levels of plasma corticosterone. Preshock experienced rats also showed marked increases of MHPG-SO4 levels in the same regions described above and elevated plasma corticosterone levels when placed but not shocked in the same environment in which the rats had previously received shocks. The effects of psychological stress on brain NA turnover were affected by the animal's shock history preferentially in the hypothalamus and amygdala. These results suggest that a purely psychological stressor caused acutely enhanced NA turnover in specific brain regions; regional NA activity appeared to be reinstated simply by reexposure to the environment previously associated with shock; preshock experience further intensified the enhancement of amygdaloid NA turnover evoked by psychological stress. An additional experiment, studying the aftereffects of preshock experience, clearly showed that these findings result from sensitization or conditioning to the environment previously paired with shock, and not merely from the aftereffects of the shock per se.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estresse Psicológico
/
Encéfalo
/
Norepinefrina
Limite:
Animals
Idioma:
En
Revista:
Pharmacol Biochem Behav
Ano de publicação:
1986
Tipo de documento:
Article