Differential Effects of Short- and Long-Term Early Maternal Separation on Subsequent Maternal Behavior in Rats

Abstract

Female Sprague-Dawley pups were separated from mothers every other day for 8 hr (long-term separation/LTS), 4 hr (short-term separation/STS), or 0 hr (no separation/NS) from postnatal day 2-20. In adulthood, they were mated and tested for maternal behaviors during two lactations. It was expected that females separated from mothers as pups would show deficits in maternal behavior as adults. Contrary to expectations, LTS showed better nest building and grouped young faster during both lactations. LTS were first to display aggression and displayed more aggression during the second lactation. Notably, while some measures decreased from first to second lactation in NS and STS, LTS maintained levels of maternal care. These results suggest that extended periods of maternal separation may exaggerate some aspects of maternal behavior.

Neonatal interventions differently affect maternal care quality and have sexually dimorphic developmental effects on corticosterone secretion

“…In accordance, behavioral stability has been observed across consecutive litters of the same dam (Champagne et al, 2003). However, as demonstrated here and in other studies (Bodensteiner et al, 2012; Macrí et al, 2004; Pryce et al, 2001; Reis et al, 2014), dams adapt their behavior to meet pups’ demands (Pereira and Ferreira, 2016) and to the environmental conditions. Some adaptations seem to persist to subsequent maternal experiences, even if the source of stress is removed (Wong et al, 2011), implying that a learning component also exists in maternal care (Scanlan et al, 2006).…”

“…* represents statistically significant difference between MS and NH groups; # represents statistically significant difference compared to NH and MS groups, in the same observation cycle; $ represents statistically significant difference compared to NH and H groups, in the same observation cycle. p Values are presented in subsection 3.1. in other studies (Bodensteiner et al, 2012;Macrí et al, 2004;Pryce et al, 2001;Reis et al, 2014), dams adapt their behavior to meet pups' demands (Pereira and Ferreira, 2016) and to the environmental conditions. Some adaptations seem to persist to subsequent maternal experiences, even if the source of stress is removed (Wong et al, 2011), implying that a learning component also exists in maternal care (Scanlan et al, 2006).…”

“…In rodents, removing pups from the nest, either for brief (handling) or long periods (maternal separation), increases the frequency of pup-directed behaviors by dams (Bodensteiner et al, 2012;Macrí et al, 2004;Pryce et al, 2001), although some studies present opposite results (Aguggia et al, 2013;Boccia et al, 2007;Reis et al, 2014). It has been proposed that the long-term consequences neonatal interventions have on the offspring, particularly concerning the adaptive programming of the HPA axis by early handling in rodents, result from the changes that this intervention induces on the dams behavior (Cirulli et al, 2003;Denenberg, 1999;Kuhn and Schanberg, 1998;Liu et al, 1997;Meaney et al, 1985).…”

Comportamento Materno: Uma Revisão Da Inter-Relação Com A Toxicologia Do Desenvolvimento Em Roedores

“…Na preparação para o parto, as fêmeas apresentam aumento na agressividade em relação a intrusos e confeccionam o ninho para acolher os filhotes (MAYER; ROSENBLATT, 1984;BRIDGES, 2015). Os roedores utilizam suas bocas como principal instrumento para o comportamento materno, uma vez que, as fêmeas limpam os filhotes à medida que vão nascendo, ingerem os sacos amnióticos junto das placentas e recolhem os filhotes para dentro do ninho (LONSTEIN; LÉVY; FLEMING, 2015).…”

“…Em ratas, os cuidados maternos podem ser agrupados didaticamente em duas categorias: os diretos e os indiretos. Os diretos são aqueles dirigidos aos filhotes, como por exemplo a busca, o agrupamento, ficar sobre os filhotes aquecendoos e alimentando-os, enquanto os indiretos são a agressividade voltada a intrusos e a construção do ninho (NUMAN, 1994;BRIDGES, 2015). Numan (1994) descreveu alguns parâmetros típicos do comportamento materno em ratas, como a busca e o agrupamento dos filhotes, a postura de amamentação, em que a coluna vertebral fica arqueada facilitando a amamentação (cifose fisiológica ou crouching), e o comportamento maternal total, caracterizado pela cifose fisiológica sobre os filhotes em amamentação.…”