GFRAL-expressing Neurons Suppress Food Intake via Aversive Pathways

The TGFß cytokine family member, GDF15, reduces food intake and body weight and represents a potential treatment for obesity. Because the brain stem-restricted expression pattern of its receptor, GDNF Family Receptor a–like (GFRAL), presents an exciting opportunity to understand mechanisms of action for area postrema neurons in food intake, we generated GfralCre and conditional GfralCreERT mice to visualize and manipulate GFRAL neurons. We found infection or pathophysiologic states (rather than meal ingestion) stimulate GFRAL neurons. TRAP-Seq analysis of GFRAL neurons revealed their expression of a wide range of neurotransmitters and neuropeptides. Artificially activating GfralCre-expressing neurons inhibited feeding, decreased gastric emptying, and promoted a conditioned taste aversion (CTA). GFRAL neurons most strongly innervate the parabrachial nucleus (PBN), where they target CGRP-expressing (CGRPPBN) neurons. Silencing CGRPPBN neurons abrogated the aversive and anorexic effects of GDF-15. These findings suggest that GFRAL neurons link non-meal-associated, pathophysiologic signals to suppress nutrient uptake and absorption. Overall design: 5 bead and 5 paired supernatant samples