WIKIMEDIA, ALLEN INSTITUTE FOR BRAIN SCIENCEBy increasing odor detection, cannabinoid type-1 (CB1) receptors in the olfactory bulb help mediate feeding behavior in fasted mice, according to a study published in Nature Neuroscience today (February 9). Researchers from the French Institute of Health and Medical Research (INSERM) and elsewhere have uncovered CB1 receptor-dependent mechanisms through which endocannabinoids and exogenous cannabinoids like THC, the active ingredient in marijuana, increase olfaction and subsequent fasting-induced food intake, and suggest that their work points to potential therapeutic targets for feeding behavior-related human diseases like anorexia and obesity.
“The study clearly establishes the relationship of food intake and olfactory processing and implicates the endocannabinoid system as a key player in this signaling pathway,” said Howard University College of Medicine’s Thomas Heinbockel, who has investigated the endocannabinoid system’s functions in the olfactory bulb, but was not involved in the work.
In 2010, INSERM’s Giovanni Marsicano and his colleagues showed that deletion of CB1 from cortical glutamatergic or GABAergic neurons had opposing effects on fasting-induced food intake in mice, implicating the endocannabinoid system in control of feeding behavior. For the present study, the researchers used pharmacological and genetic manipulations as well as an optogenetic approach to investigate connections between sensory input with central processing in the olfactory bulb and subsequent feeding behavior. They found that ...
