Development and expression of maternal behavior in naïve female C57BL/6 mice

Abstract

Naïve female mice are usually described as spontaneously maternal. We investigated how many exposures to pups (15 min vs. 1 hr) were needed to induce full maternal behavior (FMB) in 20-22, 30-35, 60-65-days-old naïve female mice (C57BL/6), and how cohabitation with the parturient mother and newborn siblings facilitated juvenile maternal behavior (MB). Only 20% of the adults displayed FMB immediately after the first exposure to pups. Incomplete MB was present in 11%, 20%, and 30% of juveniles, adolescents and adults, respectively. Three-sixty minute exposures to pups induced FMB in all adult subjects. All naïve juveniles that were not exposed to their siblings and maternal fluids failed to show maternal behavior. In contrast, more than half of the juveniles present at their homecage during delivery of a second litter showed incomplete MB (34.5%) or FMB (21.5%) when tested individually housed in a novel cage. This study suggests that most adult female mice are not spontaneously maternal but gradually sensitized. Besides, naïve juveniles could be inhibited or not motivated to show MB, but display adult-like behavior toward pups if previously exposed to newborn siblings and maternal fluids.

Are age and sex differences in brain oxytocin receptors related to maternal and infanticidal behavior in naïve mice?

“…As previously described and discussed in detail in Alsina-Llanes et al (2015), the higher incidence of maternal behavior found in adult compared to juvenile female mice agreed with previous studies (Gandelman, 1973a,b;Noirot, 1969Noirot, , 1972. However, the small percentage of full maternal animals (20%) found on the first exposure to pups in our study disagreed with several previous studies (70 to 100%; Calamandrei and Keverne, 1994;Gandelman, 1973a;Gandelman and vom Saal, 1975;Leussis, et al, 2008;Noirot, 1969Noirot, , 1972Stolzenberg and Rissman, 2011).…”

“…Several factors have been proposed in the literature to explain age and sex differences in parental and infanticidal behavior (Alsina-Llanes et al, 2015;Kuroda et al, 2011;McCarthy and vom Saal, 1986;Svare and Mann, 1981). In the current study we investigated whether the oxytocinergic system could be related to age and sex differences in parental or infanticidal behavior in naïve mice.…”

“…Adult females and males are commonly described as spontaneously maternal or infanticidal respectively (Calamandrei and Keverne, 1994;Gandelman, 1973a,b;Gandelman and vom Saal, 1975;Leussis et al, 2008;Noirot, 1969Noirot, , 1972Stolzenberg and Rissman, 2011;Svare, and Mann, 1981). However, other authors have found that at least half of the females did not show maternal behavior, and a small percentage of naïve adult males showed paternal behavior (Alsina-Llanes et al, 2015;Brown et al, 1996;Hamaguchi-Hamadaa et al, 2004;Kennedy and Elwood, 1988;Kuroda et al, 2011;Lucas et al, 1998;McCarthy and vom Saal, 1986;Pedersen et al, 2006). In the case of young females and males, the literature suggested that they showed lower incidence of maternal or infanticidal behavior respectively (Gandelman, 1973a,b;McCarthy and vom Saal, 1986;Noirot, 1972).…”

Cocaína durante la gestación y conducta materna postparto en ratones

“…Por esta razón, desde el nacimiento empieza la relación interpersonal más importante, en la cual la madre provee a los neonatos de los cuidados necesarios para sobrevivir y madurar (Alsina-Llanes, Brun & Olazábal, 2015;Wickham, Senthilselvan, Wild, Hoglund & Colman, 2015), y, al mismo tiempo, regula las respuestas emocionales que favorecen el adecuado crecimiento y desarrollo cognitivo (atención, memoria, aprendizaje, etc. ) de los recién nacidos (Kristal, 2009).…”

“…Específicamente, se han identificado diferentes pautas conductuales de la madre en el postparto, tales como la construcción del nido, arquear la espalda para dar calor y facilitar la lactancia, el lamido, el aseo o la recuperación de las crías para regresarlas al nido; además de comer y beber para el auto-mantenimiento de la madre y de las crías, el auto-aseo para eliminar posibles elementos nocivos, y facilitar la locomoción o desplazamiento y el descanso (Alsina-Llanes et al, 2015;Angoa-Perez & Kuhn, 2015;Champagne et al, 2003;Kristal, 2009;Silverman, 1978;Wang & Storm, 2011). De esta amplia gama de conductas es importante mencionar que las que implican el contacto físico entre madre y crías, como el lamido, la lactancia, el calor y el regreso al nido, entre otras, tienen un fuerte impacto en el apego y la regulación del vínculo en los roedores (Angoa-Perez & Kuhn, 2015;Champagne et al, 2003;Hertenstein, Verkamp, Kerestes, & Holmes, 2006;Pereira & Ferreira, 2015).…”