Influence of the offspring sex on the energetic balance and neurons immunoreactive to the melanin concentrating hormone in the medial preoptic area of lactating rats

• Grant number: 22/04171-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2022
• End date: September 30, 2023
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Principal Investigator: Jackson Cioni Bittencourt
• Grantee: Larissa Aveiro do Carmo
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 16/02224-1 - The existence of neurogenesis during the lactation period, AP.TEM

Abstract

The MCH (melanin-concentrating hormone) is a peptidergic system composed by neuropeptides andmany receptors subtypes, this peptide is found in the ventromedial part of medial preoptic area(vmMPOA) acts like a modulator of motivated behaviors, among then, maternal behavior. It was noted that the quantity of this neuromodulator/neuropeptide has a directly proportional relationship to the number of pups in the litter. The present study has the objective to observe if exists an influence of the sex of the offspring on the amount of MCH-ir in the vmMPOA. Five experimental groups of mothers, thatmust be primiparous lactating, with a determined number of pups of each sex, being six females on each (n = 6). The control group will consist of five males and five females, one group will have only male pups, and another will only have female pups, and still have two intermediate groups with seven pups of a determinate sex and three pups of the other. On the 19th day of lactation, through a transcardiac perfusion, the brain will be dissected and sliced. After identifying the area of interest, MCH-ir neurons will be stained by peroxidase immunohistochemistry, quantified and the data obtained will be submitted to a statistical analysis. Based on reference literature the hypothesis to be tested is that litter sex influences the amount of MCH-ir in the medial pre-optic area, once the care and attention that puppies of each sex are different.