Life events-induced decrease of corticosteroid type I receptors is associated with reduced corticosterone feedback and enhanced vulnerability to amphetamine self-administration.
In this study, we attempted to find out whether a social stress-induced increase in the vulnerability to acquire amphetamine self-administration was associated with a change in number of hippocampal corticosteroid receptors. This was examined in two types of sex-mixed colonies of rats. Animals were maintained for 4 weeks in: (1) 'stable social condition', membership did not change after constitution of the colony; (2) 'unstable social condition', the males were changed daily in a random design. The animals living in the 'stable social' conditions had: (1) a lower number of hippocampal type I corticosteroid receptors; (2) a longer duration of the increase in plasma corticosterone after exposure to novelty; (3) a higher vulnerability to acquire amphetamine self-administration. These findings suggest that a decrease in hippocampal type I corticosteroid receptors may be one of the biological mechanisms responsible for the impaired corticosterone feedback control observed in vulnerable animals. These findings throw more light on the role of hypothalamo-pituitary-adrenal axis in the modulation of adaptive behavior. The availability of drugs which are specific for corticosteroid receptors could represent a new approach to the therapy of certain behavioral disturbances.
Maccari
S
S
Laboratoire de Psychobiologie des Comportements Adaptatifs, INSERM U259, Bordeaux, France.
Piazza
P V
PV
Deminière
J M
JM
Lemaire
V
V
Mormède
P
P
Simon
H
H
Angelucci
L
L
Le Moal
M
M
D000315:Adrenalectomy; D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D003345:Corticosterone / Q000502:physiology*; D004777:Environment; D005246:Feedback; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008297:Male; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D012646:Self Administration; D013315:Stress, Psychological / Q000378:metabolism / Q000523:psychology*
D011965:Receptors, Glucocorticoid; D000661:Amphetamine; D003345:Corticosterone