Hormonal and structural transformations in the caregiver's brain: Examining themes in parental neurobiology.

When becoming a parent, caregivers undergo complex, and sometimes permanent, neurobiological alterations, and this area of neurobiology has been extensively studied for decades. Due to ethical concerns and experimental limitations, the first parental neurobiology experiments were exclusively performed using rodent animal model systems, such as mice, rats, and voles. More recent technological advancements, such as the functional MRI (fMRI) scan, have become widely adopted and led to great insight into the impact of parenting on human neurobiology. In this thematic literature review, we present key studies that provide insight into the relationship of pregnancy and parturition on maternal caregiving behavior and the relationship of postpartum on all parents. First, we examine the relationship of endocrine hormones such as estrogen, progesterone, oxytocin, and testosterone with the neurobiological development of a parent. Next, we describe the significant transformation of subcortical maternal circuit components that occur during pregnancy, and the changes in the volume of grey and white matter generated during the postpartum. These brain structure alterations contribute to the development of parental nurturing behaviors.