Preoptic Inputs and Mechanisms that Regulate Maternal Responsiveness

Abstract

The preoptic area is a well-established centre for the control of maternal behaviour. An intact medial preoptic area (MPOA) is required for maternal responsiveness as lesion of the area abolishes maternal behaviours. Whereas hormonal changes in the peripartum period contribute to the initiation of maternal responsiveness, inputs from pups are required for its maintenance. Neurones are activated in different parts of the MPOA in response to pup exposure. In the present review, we summarize the potential inputs to the MPOA of rodent dams from the litter that can activate MPOA neurones. The roles of potential indirect effects through increased prolactin levels, as well as neuronal inputs to the preoptic area are described. Recent results on the pathway mediating the effects of suckling to the MPOA suggest that neurones containing the neuropeptide tuberoinfundibular peptide of 39 residues in the posterior thalamus are candidates to convey the suckling information to the MPOA.Although the molecular mechanism through which these inputs alter MPOA neurones to support the maintenance of maternal responding is not yet known, altered gene expression is a likely candidate. Here, we summarize gene expression changes in the MPOA that have been linked to maternal behaviour and explore the idea that chromatin remodelling during motherinfant interactions mediates the long-term alterations in gene expression that sustain maternal responding.

The neurobiology of mammalian parenting and the biosocial context of human caregiving

“…Rodent studies on the maternal brain -originating with Rosenblatt's studies (Rosenblatt and Lehrman, 1963;Rosenblatt, 2003;Rosenblatt et al, 1994), addressed the critical role of the medial pre-optic area (MPOA) in the hypothalamus for the initiation of maternal behavior. Primed by the hormones of pregnancy and triggered by the increase in oxytocin and prolactin during parturition, the MPOA projects to the mesolimbic dopamine circuits, including VTA and NAcc, which increases maternal motivation to care for infants and places incentive value on stimuli from the child (Dobolyi et al, 2014;Numan and Stolzenberg, 2009;Shahrokh et al, 2010). The MPOA also projects to the amygdala, which increases maternal vigilance for infant safety (Been and Petrulis, 2012;Sheehan et al, 2001).…”

Interactions between prolactin and kisspeptin to control reproduction

“…In addition, prolactin is also known as an important factor that mediates adaptive responses related to maternal behaviors. In this case, the effects of prolactin on maternal care depend on neurons distributed in the preoptic area (29). In rodents, maternal care can be analyzed by evaluating the latency of the animal to exhibit behaviors, such as retrieving pups to the nest, grouping them and crouching over them for a set amount of time.…”

Neuronal serotonin in the regulation of maternal behavior in rodents

“…The medial preoptic area (MPOA) is a well-established centre for the control of maternal behavior [25] . It expresses receptors of hormones that enhance parental behaviors and neurons in this area activate when a mouse or rat takes care of her pups [4] .…”

“…An intact MPOA is required for maternal responsiveness because lesions of this area disrupt maternal behaviors such as pup retrieval, nest building, nursing and maternal aggression [26] . Neurons in different parts of the MPOA are activated with pup exposure [25] and stimulation of this brain area is sufficient to activate maternal responses [26] . Different subregions or neuron populations within the MPOA may influence differently specific aspects of maternal behavior [4] .…”