Lack of hypophagia in CB1 null mice is associated to decreased hypothalamic POMC and CART expression.

BACKGROUND:

Cumulative data indicate that the endocannabinoid system plays a major role in feeding behaviour and energy balance. Genetic silencing of cannabinoid receptor type 1 (CB1) reduces body weight gain, independently of food intake.

METHODS:

In this work, we investigated whether hypothalamic neuropeptide expression pattern supports the absence of anorexigenic response observed under constitutive CB1 ablation, by using neuronal CB1 conditional null mice (CamK-CB1-KO) and whole body CB1 null mice (CB1-KO).

RESULTS:

Our data showed that both CB1 null models display a marked decrease in proopiomelanocortin (POMC) and CART expression in the arcuate nucleus of the hypothalamus (ARC).

CONCLUSIONS:

This evidence suggests that lack of hypophagia is associated with the suppression of ARC anorexigenic neuropeptides and that behavioral changes in food intake (or lack thereof) after constitutive CB1 ablation are likely mediated by impaired melanocortin and CART signaling in the hypothalamus.
© The Author 2014. Published by Oxford University Press on behalf of CINP.