The reproductive experience can make a mother more resistant to pain? Molecular aspects, physiological and behavioral aspects of nociception in rats: role of delta opioid receptor

• Grant number: 12/06988-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2012
• Effective date (End): June 30, 2013
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Principal Investigator: Elizabeth Teodorov
• Grantee: Luana Carvalho Cezar
• Host Institution: Centro de Matemática, Computação e Cognição (CMCC). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil

Abstract

It is the popular belief that a mother undergoes any sacrifice to ensure the survival of her child, whether human or animal species. We also know that motherhood makes the mother more aggressive with strangers and that his pain threshold seems to reach very high levels, since this can be subjected to cold, heat, and intense hunger since your child anything to suffer. Thus it is assumed that the woman/female has an input to be maternal, particularly when there is the presence of the child/offspring and that there is an endogenous analgesic mechanism activated when the female is in this situation. The emergence and maintenance of so-called maternal behavior (CM) are controlled by the interaction of environmental, biochemical, hormonal, and neural. Analyzing districts of rodent brain involved in modulation of the MC as the medial preoptic area (MPOA) came also to other regions such as the periaqueductal gray (PAG), an important region involved in reproduction, food intake, nociception, and aggressive due to high density of opioid receptors, and striatal and hypothalamic as a whole. There are few studies that focus on the role and molecular biology of the subtypes of opioid receptors (known as mu, kappa, and delta) as well as they could modulate nociception in lactating rats, starting from the principle that an experienced mother has a higher threshold for pain and this could increase with multiparity. This project aims to investigate whether rats nulliparous, prim parous, or multiparous have molecular alterations in the expression of delta-opioid receptors in the PAG, hypothalamus, and striatum, as well as sensitivity to pain and patterns of sex hormones. The hypothesis for the study is that the expression of genes coding for these regions in the brain opioid receptors and their protein products could be modulated by maternal experience with implications on nociceptive processes essential for the survival of the species, plus possible modulation of this scenario by the action of reproductive hormones.(AU)