ISSN:
1432-2072
Keywords:
Adrenoceptor
;
Behaviour FG7142
;
Noradrenaline
;
Seizures
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract We have reported previously an increase in the number of β-adrenoceptors in mouse cerebral cortex 7 days after kindling of seizures by repeated once-daily administration of the benzodiazepine receptor inverse agonist, FG7142. In subsequent experiments, an even larger increase in β-adrenoceptor number was found 7 days after a single injection of this compound. The present experiments investigated whether FG7142-induced changes in adrenoceptor binding are also found in the rat and whether the effects of a single and repeated injections of this drug differ quantitatively. In view of the anxiogenic effects of FG7142, we have also tested for parallel changes in behaviours associated with anxiety and exploration. Nine days after a single injection of FG7142, the number of β-adrenoceptors in the cerebral cortex was greater than that found after repeated administration of this compound; this difference was statistically significant. There was no difference in β-adrenoceptor binding to tissues from chronically FG7142-treated and vehicle-injected animals and there were no changes in α2-adrenoceptor binding or noradrenaline levels after either a single or repeated FG7142 treatment. Neither single nor repeated FG7142 treatment modified spontaneous behaviour in either the elevated plus-maze test of anxiety or the holeboard test of exploration. The behavioural effects of yohimbine and clenbuterol in these tests were also unaffected by FG7142. We discuss the possibility that the difference in the effects of a single and repeated administration of FG7142 on β-adrenoceptor binding is related to the expression of kindled seizures.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00451698
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