Enteroendocrine cell types that drive food reward and aversion

Animals must learn through experience which foods are nutritious and should be consumed, and which are toxic and should be avoided. Enteroendocrine cells (EECs) are the principal chemosensors in the GI tract, but investigation of their role in behavior has been limited by the difficulty of selectively targeting these cells in vivo. Here we describe an intersectional genetic approach for manipulating EEC subtypes in behaving mice. We show that multiple EEC subtypes inhibit food intake but have different effects on learning. Conditioned flavor preference is driven by release of cholecystokinin whereas conditioned taste aversion is mediated by serotonin and substance P. These positive and negative valence signals are transmitted by vagal and spinal afferents, respectively. These findings establish a cellular basis for how chemosensing in the gut drives learning about food. Overall design: For Sample 1, we isolated Neurog3-Cre+ cells from the intestinal epithelium of mice by flow cytometry. We then processed single cells using the GemCode Single Cell Platform (10x Genomics) and sequeced single-cell cDNA libraries using an Illumina Highseq 4000. For Sample 2, we isolated CCK-Cre+ and CCK-Cre- cells from the intestinal epithelium of mice by flow cytometery. Half the mice were overnight fasted and the others were fasted and then allowed to refeed Ensure before sacrifice. Total RNA was prepared from CCK-Cre+ and CCK-Cre- cells from each mouse and then sequenced using an Illumina HiSeq 2500.