Recording and neural circuit-based manipulation of the maternal oxytocin pulses in mice

Abstract

SummaryFor mammals, successful parturition and breastfeeding are critical to the survival of offspring. Pulsatile release of the hormone oxytocin mediates uterine contraction during parturition and milk ejection during lactation. These oxytocin pulses are generated by unique activity patterns of the central neuroendocrine oxytocin neurons located in the paraventricular and supraoptic hypothalamus. However, the maternal activities of oxytocin neurons remain elusive because most classical electrophysiological studies in anesthetized rats have lacked the genetically defined cell identity of oxytocin neurons. We herein introduce viral genetic approaches in mice to characterize the maternal pulsatile activities of oxytocin neurons by fiber-photometry-based chronic in vivo Ca2+ imaging. We also demonstrate the pharmaco-genetic manipulation of oxytocin pulses during lactation via activating a prominent pre-synaptic structure of oxytocin neurons defined by retrograde trans-synaptic tracing. Collectively, our study opens a new avenue for the neuroscience of maternal neuroendocrine functions.