Prolactin is a hormone which drives many neural adaptations during pregnancy and lactation, including the suppression of behavioural and endocrine stress responses. This adaptation benefits the mother and protects the child from excessive stress during the perinatal period. Corticotropin-releasing hormone (CRH) neurons control the neuroendocrine stress response. Prolactin inhibits the output of this neural network, however, CRH neurons do not express prolactin receptors, indicating that prolactin signalling must be relayed from upstream neural populations. The medial preoptic area (MPOA) has one of the highest densities of prolactin receptors in the brain and also sends direct projections to CRH neurons. This current project will determine how prolactin sensitive neurons in the MPOA control CRH neurons and hence stress responses during pregnancy and lactation. This will give important insight into a form of neural plasticity essential for safeguarding the health of mother and child during the perinatal period.