Additive wake-promoting actions of medial basal forebrain noradrenergic alpha1- and beta-receptor stimulation.

The locus coeruleus-noradrenergic system exerts an activating influence on forebrain neuronal and behavioral activity states, in part through the actions of noradrenergic beta-receptors in the medial septal (MS) and medial preoptic (MPOA) areas. MPOA alpha1-receptors exert similar wake-promoting actions. The current study examines the influence of alpha1-receptors located within MS on sleep-wake state. In addition, the extent to which alpha1- and beta-receptors located within MS and MPOA interact in the modulation of behavioral state was investigated by examining the effects of individual or combined infusion of alpha1- and beta-agonists into these regions. Results show that alpha1-receptors located within MS exert wake-promoting actions. Within both MS and MPOA, additive wake-promoting actions were observed with alpha1- and beta-receptor stimulation, the sum of which contributes to the overall arousal state of the animal.