Changes in maternal behavior of Wistar rat dams separated from their offspring on postnatal days 3 or 11

• Grant number: 19/05661-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2019
• End date: August 31, 2021
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Principal Investigator: Deborah Suchecki
• Grantee: Carolina Eun Ji Kim
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Maternal behavior (MB) is essential for the development and survival of puppies. The MB is more intense after birth and gradually decreases with the maturation of the puppies. This behavior is stimulated by hormonal factors (estrogen, progesterone, oxytocin, and prolactin) and mainly by the demand of puppies that emit ultrasonic vocalizations and perform body movements to attract the mother's attention. During maternal deprivation (MD), puppies are separated from their mothers for 24 hours, without food and with only maintaining body temperature. This event makes puppies extremely demanding when reunited with their mothers. In a previous study, we observed that maternal deprivation increases the frequency of breastfeeding and anogenital licking, especially in the first hour after the reunion. In addition, these changes are dependent on the pups' age that they were deprived. However, in this study behaviors before MB was not evaluated and there was no comparison with the non-private control group to understand how and how much these behaviors were modified by MD. Thus, the main objective of this study will be to evaluate the MB, qualitative (breastfeeding types and the location of licking the pup behavior - whether in the anogenital region or the body) and quantitatively (frequency of these behaviors) during pup development before and after maternal deprivation on postnatal days 3 or 11. Therefore, 30 mothers will be evaluated, divided into 3 groups (10 mothers per group): 1. Control, not separate from pups (CTL), 2. Separated in the postpartum day 3 (SEP3), 3. Separated postpartum day 11 (SEP11). The MB will be evaluated on postpartum days 2 (PP2 - the day before MD), PP4 (immediately after MD on day 3), PP10 (the day before MD) and PP12 (immediately after MD on day 11). There will be 4 sessions on each observation day, lasting 1 hour and recording the behaviors expressed by the mothers every 3 minutes, totaling 20 observations per session. These behaviors will be compared to those of CTL mothers, on the same days and time of evaluation. Data will be analyzed for normality and depending on the distribution will be used parametric or nonparametric statistical analysis, comparing the groups throughout the development.