Pituitary adenylate cyclase-activating polypeptide (PACAP) acts in the nucleus accumbens to reduce hedonic drive.

Obesity develops, in part, due to frequent overconsumption. Therefore, it is important to identify the regulatory mechanisms that promote eating beyond satiety. Previously, we have demonstrated that an acute microinjection of the neuropeptide PACAP into the nucleus accumbens (NAcc) attenuates palatable food consumption in satiated rats. To better understand the mechanism by which intra-NAcc PACAP selectively blocks palatable food intake, the current work employed a rodent taste reactivity paradigm to assess the impact of PACAP on the hedonic processing of a 1% sucrose solution. Our results revealed that bilateral intra-NAcc PACAP infusions significantly reduced appetitive orofacial responses to sucrose. Interestingly, the effect of PACAP on the expression of aversive responses to sucrose was dependent on the rostral-caudal placement of the microinjection. In a separate group of rats, PACAP was microinjected into the hypothalamus (a region of the brain in which PACAP does not attenuate palatable feeding). Here we found that PACAP had no effect on the hedonic perception of the sucrose solution. Taken together, this dataset indicates that PACAP acts in specific subregions of the NAcc to attenuate palatability-induced feeding by reducing the perceived hedonic value of palatable food.

Red ear syndrome: a case series and review of the literature.

BACKGROUND: Red Ear Syndrome is a burning sensation and erythema of the ear, associated with a various number of disorders including migraine, trigeminal neuralgia, autoimmune disorders etc. Theories for RES pathophysiology have developed from current understandings of comorbid conditions. Characterizing the underlying mechanism of RES is crucial for defining effective treatments. CASE PRESENTATION: Three caucasian patients, ages 15, 47, and 67 years, with migraine, one with erythromelalgia are reported in this manuscript. RES pathophysiology is not fully understood due to its variable clinical presentation and numerous comorbid conditions, making it difficult to identify effective treatments. CONCLUSION: RES seems to be largely treatment-resistant, and most options involve treating the associated disorders and minimizing pain. Further investigation of future cases should lead to a more comprehensive understanding of the fundamental cause of RES and, hopefully, successful treatments.