PACAP-expressing neurons in the lateral habenula diminish negative emotional valence.

The lateral habenula (LHb) is a small, bilateral, epithalamic nucleus which processes aversive information. While primarily glutamatergic, LHb neurons express genes coding for many neuropeptides, such as Adcyap1 the gene encoding pituitary adenylate cyclase-activating polypeptide (PACAP), which itself has been associated with anxiety and stress disorders. Using Cre-dependent viral vectors, we targeted and characterized these neurons based on their anatomical projections and found that they projected to both the raphe and rostromedial tegmentum but only weakly to ventral tegmental area. Using RiboTag to capture ribosomal-associated mRNA from these neurons and reanalysis of existing single cell RNA sequencing data, we did not identify a unique molecular phenotype that characterized these PACAP-expressing neurons in LHb. In order to understand the function of these neurons, we conditionally expressed hM3 Dq DREADD selectively in LHb PACAP-expressing neurons and chemogenetically excited these neurons during behavioral testing in the open field test, contextual fear conditioning, sucrose preference, novelty suppressed feeding, and conditioned place preference. We found that Gq activation of these neurons produce behaviors opposite to what is expected from the LHb as a whole-they decreased anxiety-like and fear behavior and produced a conditioned place preference. In conclusion, PACAP-expressing neurons in LHb represents a molecularly diverse population of cells that oppose the actions of the remainder of LHb neurons by being rewarding or diminishing the negative consequences of aversive events.

Pancreatic cancer surveillance among high-risk populations: knowledge and intent.

Pancreatic cancer is the fourth most common cancer in both men and women in the United States. It has the lowest survival rate of all cancers, largely due to the presence of non-specific symptoms, leading to diagnosis at advanced stages. While the majority of cases of pancreatic cancer are sporadic, up to 10% may be associated with an inherited predisposition. Currently, there is no standard screening protocol for pancreatic cancer, although this will change in the future as technology improves. Additionally, there is little information regarding the perceptions and intent to screen for pancreatic cancer among those with an increased risk due to a hereditary cancer predisposition syndrome, which was the objective of this study. Focus groups and individual telephone interviews were conducted, with questions focused on knowledge about pancreatic cancer and screening, perceived motivators, and perceived barriers related to each of the screening techniques currently available. Participants were recruited from the High Risk Breast Cancer and Pancreatic Cancer Registries at Huntsman Cancer Institute. The findings of this study indicated that individuals from these high-risk groups have low knowledge levels of pancreatic cancer screening, despite their desire for this information. Motivation to undergo a particular screening technique is related to whether the test is recommended by a physician, cost, degree of invasiveness, and comfort level. This information is useful to genetics professionals who counsel at-risk individuals, physicians who formulate patient care plans, and translational researchers who are developing pancreatic screening methods.