A lateral hypothalamus to basal forebrain neurocircuit promotes feeding by suppressing responses to anxiogenic environmental cues.

Abstract

Animals must consider competing information before deciding to eat: internal signals indicating the desirability of food and external signals indicating the risk involved in eating within a particular environment. The behaviors driven by the former are manifestations of hunger, and the latter, anxiety. The connection between pathologic anxiety and reduced eating in conditions like typical depression and anorexia is well known. Conversely, anti-anxiety drugs such as benzodiazepines increase appetite. Here, we show that GABAergic neurons in the diagonal band of Broca (DBB^GABA) are responsive to indications of risk and receive monosynaptic inhibitory input from lateral hypothalamus GABAergic neurons (LH^GABA). Activation of this circuit reduces anxiety and causes indiscriminate feeding. We also found that diazepam rapidly reduces DBB^GABA activity while inducing indiscriminate feeding. Our study reveals that the LH^GABA→DBB^GABA neurocircuit overrides anxiogenic environmental cues to allow feeding and that this pathway may underlie the link between eating and anxiety-related disorders.