Inhibition of satiety induced by activation of hypothalamic CB1 receptors

Abstract

The endocannabinoid system plays an important role in feeding behavior regulation, mainly via CB1 receptors (CB1R). The CB1R are expressed in the paraventricular hypothalamus (PVN) and it has been proposed that these receptors are mediators of the cannabinoid-induced hyperphagia; however, the behavioral mechanism has not been fully characterized. The aim of the present study was to assess the role of PVN CB1R on the expression of satiety using the behavioral satiety sequence analysis (BSS). Male Wistar rats were cannulated unilaterally in the right PVN, they were injected with the CB1R agonist, ACEA (0.25 micro g), and the BSS was evaluated during 2 hours. The BSS analysis showed that ACEA administration prevented the satiety expression and the CB1R antagonist, AM 251 (0.25 micro g), blocked the effect. The present results showed that the CB1R play a inhibitory role on satiety, which strongly suggest that the behavioral mechanism related to the cannabinoid-induced effects involves the inhibition of satiety expression.