Evidence for beta1-adrenergic receptor involvement in amygdalar corticotropin-releasing factor gene expression: implications for cocaine withdrawal.

We previously showed that betaxolol, a selective beta(1)-adrenergic receptor antagonist, administered during early phases of cocaine abstinence, ameliorated withdrawal-induced anxiety and blocked increases in amygdalar beta(1)-adrenergic receptor expression in rats. Here, we report the efficacy of betaxolol in reducing increases in gene expression of amygdalar corticotropin-releasing factor (CRF), a peptide known to be involved in mediating 'anxiety-like' behaviors during initial phases of cocaine abstinence. We also demonstrate attenuation of an amygdalar beta(1)-adrenergic receptor-mediated cell-signaling pathway following this treatment.