Critical role of lateral habenula circuits in the control of stress-induced palatable food consumption.

Chronic stress fuels the consumption of palatable food and can enhance obesity development. While stress- and feeding-controlling pathways have been identified, how stress-induced feeding is orchestrated remains unknown. Here, we identify lateral habenula (LHb) Npy1r-expressing neurons as the critical node for promoting hedonic feeding under stress, since lack of Npy1r in these neurons alleviates the obesifying effects caused by combined stress and high fat feeding (HFDS) in mice. Mechanistically, this is due to a circuit originating from central amygdala NPY neurons, with the upregulation of NPY induced by HFDS initiating a dual inhibitory effect via Npy1r signaling onto LHb and lateral hypothalamus neurons, thereby reducing the homeostatic satiety effect through action on the downstream ventral tegmental area. Together, these results identify LHb-Npy1r neurons as a critical node to adapt the response to chronic stress by driving palatable food intake in an attempt to overcome the negative valence of stress.

Low Prevalence of Amalgam-Associated Lichenoid Lesions in the Oral Cavity: A Prospective Study.

INTRODUCTION: Amalgam has been the restoration of choice for years, but its popularity has declined due to concerns about aesthetics, mercury toxicity and lichenoid lesions associated with it. Lichenoid reaction is considered to be a delayed hypersensitivity type of reaction and it has been associated with dental materials in general and amalgam in particular. MATERIALS AND METHODOLOGY: Two thousand patients having at least one amalgam restoration were examined for signs of lichenoid lesions when visiting the OPD of Conservative Dentistry and Endodontics at the Nair Hospital Dental College in Mumbai, India. Indirect spatial correlation to the amalgam restoration and the same were recorded. Descriptive analysis was used. RESULTS: Three (0.15%) out of 2000 patients with amalgam-associated lichenoid lesions showed complete resolution of lesions after the replacement of the restorations. CONCLUSION: Amalgam associated lichenoid lesions have a low prevalence and should not be a contraindication to its use in routine restorative dental practice. Patch tests and biopsies have questionable diagnostic and prognostic value. Identification of the lesions should be made after the elimination of all other causative factors for the presenting symptoms. A close spatial association of the lesion to amalgam and the regression of symptoms after its removal should be considered as confirming the diagnosis.

Lack of neuropeptide FF signalling in mice leads to reduced repetitive behavior, altered drinking behavior, and fuel type selection.

Although best known for their involvement in modulating nociception, Neuropeptide FF (NPFF) group peptides have been suggested to fulfil a variety of biological functions such as feeding, anxiety behaviors and thermogenesis. However, evidence supporting these functions of NPFF is mostly pharmacological, leaving the physiological relevance unaddressed. Here we examined the physiological impact of lack of NPFF signalling in both genders using a Npff-/- mouse model. NPFF expression in the mouse is restricted to the spinal cord and brainstem while its cognate receptor NPFFR2 has wider distribution throughout the brain. Both male and female Npff-/- mice showed reduced repetitive behaviors evidenced in the marble burying test and self-grooming test. A decrease in anxiety-related behaviors in the Npff-/- mice was also observe in the open field test and to a lesser degree in an elevated plus maze test. Moreover, both male and female Npff-/- mice exhibited increased water intake resulting from increases in drinking size, rather than number of drinking events. During a fasting-refeeding challenge, Npff-/- mice of both genders displayed alterations in reparatory exchange ratio that reflect a greater fuel type flexibility. Npff-/- mice were otherwise wild-type-like regarding body weight, body composition, feeding behaviors, locomotion or energy expenditure. Together, these findings reveal the important physiological roles of NPFF signalling in the regulation of anxiety-related and repetitive behaviors, fluid homeostasis and oxidative fuel selection, highlighting the therapeutical potential of the NPFF system in a number of behavioral and metabolic disorders.

Perceptions of the Students and Faculty of a Dental College Towards Student Evaluation of Teaching (SET): A Cross-sectional Study.

Introduction Student evaluation of teaching (SET) has been in use in some parts of the world for almost a century now. Though India has the highest number of dental colleges in the world, very few colleges employ SET as a tool for improving teaching. The present study was designed to investigate the attitudes of the faculty and students of a dental institute in India, and the differences, if any, that exist between the two major stakeholders. Materials and methods Two validated questionnaires for faculty and students about the various aspects of SET were given to consenting participants and the results of the same were statistically analyzed.  Results Forty-six faculty and 198 students participated in the study. The average age of the students was 21 years while that of the faculty was 37 years. The majority of the faculty thought of SET as a useful educational tool and were open to their teaching being evaluated, though they were divided about SET being used for appraisals. Most students wanted SET to be implemented in their institute and thought that it will improve the teaching being rendered to them. Discussion On most aspects, like the when, how often, its mode of administration, and the format of SET, there was an agreement amongst the students and faculty. They differed significantly on the visibility of SET results, where most faculty felt that the results of SET should only be known to the faculty. This can be attributed to apprehensions among the faculty about SET. Conclusion The present study concludes that SET is perceived as a useful tool by the students and faculty of the studied institution.