ACTIVATION OF FOS IN MOUSE AMYGDALA BY LOCAL INFUSION OF NOREPINEPHRINE OR ATIPAMEZOLE

Norepinephrine (NE) is known to activate a number of immediate-early g enes (IEGs) in the brain which map be involved in prolonged changes in neuronal function. To investigate the function of these genes it woul d be useful to have a model system in which they are induced in specif ic populations of cells in specific brain regions without systemic dru g administration which can affect multiple sites. Tn the present paper we have shown that local infusions of NE or of the alpha(2)-adrenocep tor antagonist, atipamezole, in the mouse amygdala produces localized expression of fos. The expression of fos was blocked by a cocktail of an alpha(1)- (prazosin) and beta(1)-adrenoceptor (betaxolol) blocker b ut not by a selective 5-HT1A blocker (WAY100135). Prazosin and betaxol ol did not have a nonspecific reducing action on fos expression. It is concluded that localized expression of fos after NE infusion in the m ouse amygdala represents a model system for further studies of the rol e of IEG expression in central noradrenergic function. (C) 1997 Elsevi er Science B.V.