Effect of noradrenergic denervation of the amygdala upon recovery after sleep deprivation in the rat.

We previously showed that the noradrenergic locus coeruleus (NA-LC) was involved in the regulatory mechanisms of the paradoxical sleep rebound following a 10 h sleep deprivation by using a systemic injection of a specific neurotoxin, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4). Given that rebound mechanisms are mainly located in the forebrain, we planned to study the role of the forebrain structures receiving LC afferences. In this study we evaluated the involvement of noradrenergic afferences to the central nucleus of the amygdala in the sleep rebound by DSP-4 microinjections into the central nucleus of the rat amygdala. The results showed that during the first recovery day, the paradoxical sleep rebound is lower in DSP-4 treated rats (-67.28%). These findings indicate that the amygdala, through its NA afferents, contributes to the sleep rebound mechanisms.