Figure 12.

Model depicting key neural and neuroendocrine relationships associated with experience-enhanced maternal care. Key modifications occur within the MPOA and NA as a function of prior maternal experience which result in enhanced responsiveness to pups. These changes include increased expression of the PRL-R, STAT5B and ESR1 1b promoter within the MPOA that result in increased activity and responsiveness of the ESR1 system which in turn increases the saliency of sensory stimuli. Likewise, there appears to be an increase in the social reward value of stimuli from young mediated by the NA oxytocinergic and dopaminergic systems. It is hypothesized that this change in social reward results in part from an increase in serotoninergic activity on oxytocin neurons in the NA. Interestingly, the activity within these systems in the MPOA and NA are both affected by suckling stimuli via the suckling afferent pathway (Tindal & Knaggs, 1977). Suckling stimuli are processed through the dorsal raphe by serotonergic inputs to the NA (Dölen et al., 2013) and indirectly through suckling afferents via a thalamic relay to the MPOA (Cservenak et al., 2010) that also increase prolactin release. Together, it is postulated that these experience-induced changes in neurochemical sensitivity render the maternal neural network more sensitive to neurotropic stimulation of maternal care by the lactogenic and estrogen receptor systems.