Paternal Deprivation and Female Biparental Family Rearing Induce Dendritic and Synaptic Changes in Octodon degus: II. Nucleus Accumbens

Abstract

While the majority of studies on the importance of parental caregiving on offspring behavioral and brain development focus on the role of the mother, the paternal contribution is still an understudied topic. We investigated if growing up without paternal care affects dendritic and synaptic development in the nucleus accumbens of male and female offspring, and if replacement of the father by a female caregiver “compensates” the impact of paternal deprivation. We compared a) biparental rearing by father and mother b) mono-parental care by a single mother and c) biparental rearing by two female caregivers. Quantitative analysis of medium-sized neurons in the nucleus accumbens revealed that growing up without father resulted in reduced spine number in both male and female offspring in the core region, whereas spine frequency was only reduced in females. In the shell region reduced spine frequency was only found in males growing up in a monoparental environment. Replacement of the father by a female caregiver did not “protect” against the effects of paternal deprivation, indicating a critical impact of paternal care behavior on the development and maturation of neuronal networks in the nucleus accumbens.

Shaping the development of complex social behavior

“…Similarly, male, but not female, biparentally reared degu show higher spine frequency on basal dendrites in the ventral medial prefrontal cortex (mPFC) compared to singly reared animals 162 . Indeed, PD in degu has been shown to have widespread effects on the number of neurons throughout the lifespan in many brain regions, including the NAc, amygdala, and hippocampus 162–164 . In mandarin voles and California mice, PD leads to reductions in the survival of new cells in the dentate gyrus of females 105,165 .…”

“…162 Indeed, PD in degu has been shown to have widespread effects on the number of neurons throughout the lifespan in many brain regions, including the NAc, amygdala, and hippocampus. [162][163][164] In mandarin voles and California mice, PD leads to reductions in the survival of new cells in the dentate gyrus of females. 105,165 PD in California mice has also been shown to lead to reductions in the volume of the dentate gyrus in both sexes and the density of microglia cells.…”