CB1 cannabinoid receptor in SF1-expressing neurons of the ventromedial hypothalamus determines metabolic responses to diet and leptin

Metabolic flexibility allows rapid adaptation to dietary change, however, little is known about the CNS mechanisms regulating this process. Neurons in the hypothalamic ventromedial nucleus (VMN) participate in energy balance and are the target of the metabolically relevant hormone leptin. Cannabinoid type(1) (CB1) receptors are expressed in VMN neurons, but the specific contribution of endocannabinoid signaling in this neuronal population to energy balance regulation is unknown. Here we demonstrate that VMN CB1 receptors regulate metabolic flexibility and actions of leptin. In chowfed mice, conditional deletion of CB1 in VMN neurons (expressing the steroidogenic factor 1, SF1) decreases adiposity by increasing sympathetic activity and lipolysis, and facilitates metabolic effects of leptin. Conversely, under highfat diet, lack of CB1 in VMN neurons produces leptin resistance, blunts peripheral use of lipid substrates and increases adiposity. Thus, CB1 receptors in VMN neurons provide a molecular switch adapting the organism to dietary change. (C) 2014 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY-NC-ND license (http.creativecommons.org/licenses/by-nc-nd/3.0/).