Investigating the NE outputs that are engaged by GLP-1 is important not only for understanding the negative side effects of obesity pharmacotherapies but also for revealing the LC circuits that contribute to anxiety and stress disorders as well as gastrointestinal dysfunctions observed in Alzheimer’s disease (110) and opioid withdrawal (111), both of which are believed to involve the LC. This evidence concerns the gene GCG and early-onset autosomal dominant Alzheimer disease.