The RET gene encodes RET protein, which triggers intracellular signaling pathways for enteric neurogenesis, and RET mutation results in Hirschsprung's disease.

Enteric neurons and ganglia are derived from vagal and sacral neural crest cells, which undergo migration from the neural tube to the gut wall. In the gut wall, they first undergo rostrocaudal migration followed by migration from the superficial to deep layers. After migration, they proliferate and differentiate into the enteric plexus. Expression of the Rearranged During Transfection (RET) gene and its protein RET plays a crucial role in the formation of enteric neurons. This review describes the molecular mechanism by which the RET gene and the RET protein influence the development of enteric neurons. Vagal neural crest cells give rise to enteric neurons and glia of the foregut and midgut while sacral neural crest cells give rise to neurons of the hindgut. Interaction of RET protein with its ligands (glial cell derived neurotrophic factor (GDNF), neurturin (NRTN), and artemin (ARTN)) and its co-receptors (GDNF receptor alpha proteins (GFRα1-4)) activates the Phosphoinositide-3-kinase-protein kinase B (PI3K-PKB/AKT), RAS mitogen-activated protein kinase (RAS/MAPK) and phospholipase Cγ (PLCγ) signaling pathways, which control the survival, migration, proliferation, differentiation, and maturation of the vagal and sacral neural crest cells into enteric neurons. Abnormalities of the RET gene result in Hirschsprung's disease.

Knowledge, Attitude and Practice of Self-Medication Among Basic Science Undergraduate Medical Students in a Medical School in Western Nepal.

INTRODUCTION: Studies have shown self-medication to be common among medical students. These studies are however, few in Nepal. The present study assessed knowledge, attitude, and practice of self-medication among second and fourth semesters' undergraduate medical students and studied differences in knowledge and attitude (if any) among different subgroups of the respondents. MATERIALS AND METHODS: A cross-sectional survey was conducted using a questionnaire among basic science medical students of Manipal College of Medical Sciences, Nepal. Semester of study, gender, age, nationality, and the profession of their parents were noted. Students' knowledge and attitude about self-medication was studied by noting their degree of agreement with a set of 40 statements using a Likert-type scale. The average scores and frequency of occurrence of particular behaviors among different categories of respondents were compared using appropriate statistical tests. RESULTS: Two hundred and seventy-six of the 295 (93.6%) students participated. The mean (SD) knowledge, attitude, and total scores were 74.54 (6.92), 67.18 (5.68), and 141.73 (10.76) with maximum possible scores 100, 100 and 200, respectively. There was no significant difference in scores according to respondents' gender, age, and the profession of their parents. However, the mean knowledge, attitude and total scores were significantly different among students of different nationalities. Mean scores of fourth semester students were significantly higher compared to second semester students. There were differences in knowledge and total scores among students of different nationalities. Eighty two percent of respondents had self-medicated during the one year period preceding the study; 149 respondents (54%) shared that previous experience with the medicine was one of the information sources for self-medication. Prevalence of self-medication among respondents according to semester of study, gender, age, and profession of the parents was not significantly different. The use of self-medication was more common among Sri Lankan respondents compared to Nepalese. Painkillers (73.2%), antipyretics (68.8%), and antimicrobials (56.2%) were most commonly used for self-medication. CONCLUSION: Students' knowledge and attitude about self-medication is good. The prevalence of self-medication among medical students was high.