Daily temporal profile of melatonin synthesis in the pineal gland and extra-pineal tissues of the subterranean rodent Ctenomys coludo

• Grant number: 24/19412-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Gisele Akemi Oda
• Grantee: Lara Barbara Nekrasius
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 22/16225-0 - Daily and Seasonal temporal organization, from behavioral to molecular levels, in subterranean rodents Ctenomys famosus, AP.R

Abstract

Daily biological rhythms are generated internally and are synchronized mainly by the light/dark cycle of the environment, allowing physiological and behavioral anticipation of daily environmental challenges. In mammals, the central oscillator, or structure that regulates daily rhythms, is situated in the suprachiasmatic nuclei (SCN) of the hypothalamus. One of the main rhythms regulated by the NSQs is the production of melatonin by the pineal gland. This hormone acts as a dark marker, regulating daily physiological processes such as the sleep-wake cycle and annual processes such as reproduction. Although its production by the pineal gland is well established, melatonin is also synthesized in other tissues, where it performs autocrine functions, regulating local tissue function and promoting protective and antioxidant actions. This project aims to expand the chronobiological study of subterranean rodents of the species Ctenomys coludo, characterizing for the first time the daily temporal profile of melatonin in the pineal and extra-pineal tissues, in different seasons of the year. This will be done using ELISA assays and high-performance liquid chromatography (HPLC). The expected results include the characterization of the rhythmic patterns of melatonin in the different tissues and the analysis of seasonal variations. These data could provide new insights into the regulation of circadian and circannual rhythms in subterranean animals and their adaptations to environments with low light exposure.