Maternal deprivation during early infancy in rats increases oxytocin immunoreactivity in females and corticosterone reactivity to a social test in both sexes without changing emotional behaviour

Author(s)

Ceschim, Viviane C. ^[1] ; Sumaran, Paula ^[1] ; Borges, Andrea A. ^[1] ; Girardi, Carlos Eduardo N. ^[1] ; Suchecki, Deborah ^[1]

Affiliation

^[1] Univ Fed Sao Paulo, Dept Psychobiol, Rua Napoleao Barros 925, BR-04023062 Sao Paulo - Brazil

• Document type: Journal article
• Source: Hormones and Behavior; v. 129, MAR 2021.
• Web of Science Citations: 0

Abstract

Impairment of social behaviour is a hallmark of emotional disorders, with increased avoidance of social contact. In rats, the 24 h maternal deprivation (DEP) paradigm is used to understand the impact of extreme neglect on neurodevelopment. Due to the distinct immediate effects of DEP on postnatal days (PND) 3 (DEP3) or 11 (DEP11), in the present study we investigated the long-term effects of DEP at these ages on anxiety-like behaviour, by recording the visits and time spent in the centre part of the open-field, social investigation of a confined, same-sex, unfamiliar animal, basal and post-social test corticosterone plasma levels and the immunoreactivity to oxytocin in the paraventricular (PVN) and supraoptic nuclei of the hypothalamus (SON). Whole litters were distributed into control (CTL), DEP3 or DEP11 groups and behavioural tests and biological samples were collected between PNDs 40 and 45 in males and females. There were no differences in the exploration of the central part of the open field or on the time investigating the unfamiliar rat. However, the percent increase in post-test corticosterone secretion from baseline was greater for both DEP3 male and female subgroups than their CTL and DEP11 counterparts. DEP3 females showed more oxytocin staining than DEP11 counterparts in magnocellular neurons of the SON and PVN. These results suggest that DEP at the ages chosen does not alter social investigation, although it results in distinct neurobiological outcomes, depending on the developmental phase when it is imposed. (AU)

• FAPESP's process: 14/13454-2 - Participation of vasopressin and oxytocin in the long-term behavioral effects of neonatal stress in Wistar rats
• Grantee: Carlos Eduardo Neves Girardi
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 08/07448-9 - Effects of 24-h maternal deprivation on the emotional memory and social behaviour of adult rats
• Grantee: Viviane Côrtes Ceschim
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 15/26364-4 - Neurobiologic mechanisms involved in the long-term emotional effects of maternal deprivation
• Grantee: Deborah Suchecki
• Support Opportunities: Regular Research Grants