Dysphoric milk ejection reflex to nipple/areolar stimulation, thoughts of the baby or of breastfeeding, or overfull breasts, travels through both brain and bloodstream, causing emotional changes in the brain and the release of milk in the breast. Prolactin, released in a gradual wave that peaks after the beginning of a feeding, is responsible for continued milk production. Dopamine inhibits the release of prolactin, so dopamine levels must drop in order for prolactin levels to rise. Some speculate that the necessary dopamine drop is similar to (and timed with) the oxytocin spike – a sort of negative image – but that in D-MER mothers it
Refractory period (physiology) the amount of time it takes for an excitable membrane to be ready for a second stimulus once it returns to its resting state following an excitation. It most commonly refers to electrically excitable muscle cells or neurons. Absolute refractory period corresponds to depolarization and repolarization, whereas relative refractory period corresponds to hyperpolarization. After initiation of an action potential, the refractory period is defined two ways: The absolute refractory period coincides with nearly the entire duration of the action potential. In neurons, it is caused by the inactivation of the Na channels that originally opened to depolarize the membrane. These