Effects of lesions of the nucleus accumbens on lactation and postpartum behavior

Abstract

An attempt was made, using the lesion technique, to confirm results of electric stimulation studies which indicate that the nucleus accumbens (NA) can exercise a facilitatory influence on oxytocin secretion and the milk ejection reflex. Since little is known about the NA, despite its large size, we also investigated other possible functions as well, especially those related to reproduction, lactation, and maternal behavior. Lesions including the dorsomedial NA were followed by heightened emotionality and impaired lactational performance, attributable in some instances to oxytocin deficiency and in others to a possible prolactin insufficiency. Poor lactational performance was accompanied by the absence of maternal behavior. Lesions made in the posterior hypothalamus reversed the latter but not the former, indicating that: (1) inferior maternal behavior was not attributable to hormonal deficiencies underlying poor lactational performance but to the generally excitable state of the animals, and (2) the hormonal deficiencies were direct consequences of the lesion and not secondarily produced by chronic sympathetic activation. © 1975, Psychonomic Society, Inc.. All rights reserved.