Action of the melanin-concentrating hormone on neurons of the medial preoptic area in the lactation phase of Sprague-Dawley rats

• Grant number: 13/03694-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2013
• End date: July 31, 2014
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Jackson Cioni Bittencourt
• Grantee: Giovanne Baroni Diniz
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 10/52068-0 - The putative envolvement of melanin-concentrating hormone in the control of lactation, AP.TEM

Abstract

The Melanin Concentrating Hormone (MCH) is an important neuropeptide, capable of performing a series of different roles in the organism, especially those related to homeostasis and motivated behavior. The lactation phase involves a series of physiological and behavioral changes that allow the females to nurture and raise their offspring, being a critical period for the species maintenance. The presence of MCH immunoreactivity in neurons of the Medial Preoptic Area (MPOA), a hypothalamic region related to the activation and maintenance of sexual and maternal behavior, exclusively during the lactation phase, indicates a possible role for this neuropeptide on the regulation of the actions displayed by the females during this period. Even if the existent literature indicates a relation between MCH and the lactation phase mediated by the MPOA, there is no data that links functionally the MCH and the regulation of maternal behavior. This way, this work aims to correlate the ending of the pre-pro-MCH messenger RNA expression (ppMCH mRNA) in MPOA neurons and the terminus of the maternal activities characteristics to the lactating females. To that end, pregnant rats will have cannulas surgically implanted on the MPOA, and on the 5th day of lactation the experimental group will receive an injection of anti-MCH antibody (which shall suppress MCH action) and the control group will receive a physiological solution injection (NaCl, 0.9%). An analysis of their behavior will be conducted where actions influenced by MCH shall be observed reduced in the experimental group. (AU)