Gene Expression in Oxytocin Neurons During Lactation

Summy-Long博士正在利用她的职业发展奖学习最先进的分子技术，这将使她能够独立研究大细胞神经分泌细胞中的基因表达。大细胞神经元合成加压素和催产素，前者是一种调节液体平衡和血压的肽，后者是哺乳期释放的一种肽，用于在哺乳和分娩时启动乳汁排出，以收缩子宫。催产素能神经元作为大细胞系统的一部分，在妊娠中期开始可塑性，并持续到哺乳期。这种可塑性表现在新的可逆突触的形成上，涉及神经元的生长和适应。虽然形态变化和电生理活动已被很好地理解，但在细胞水平上对这些适应性变化的控制的知识是基本的。Summy-Long博士将研究原癌基因，尤其是c-fos，在哺乳期经历可塑性的催产素能神经元中所起的作用。这些研究为进一步探索原癌基因在神经元中的表达方式和时间提供了基础。这项研究对生殖神经内分泌学和癌症都有意义，因为了解生理变化期间正常细胞中原癌基因的表达可能会为这种调节如何变得异常提供线索。

Dr. Summy-Long is using her Career Advancement Award to learn the state of the art molecular techniques which will allow her to investigate independently gene expression in magnocellular neurosecretory cells. Magnocellular neurons synthesize vasopressin, a peptide that regulates fluid balance and blood pressure, and oxytocin, a peptide released during lactation to initiate milk let-down in response to suckling and at parturition to contract the uterus. The oxytocinergic neurons as part of the magnocellular system undergo plasticity beginning during pregnancy at mid-gestation and lasting through lactation. This plasticity is expressed in the formation of new and reversible synapses involving growth and adaption of neurons. Although the morphological changes and electrophysiological activity are well understood, knowledge of the control of these adaptive changes at the cellular level is rudimentary. Dr. Summy-Long will examine the role that proto-oncogenes, especially c-fos, play in oxytocinergic neurons that undergo plasticity during lactation. These studies provide a foundation for probing further how and when proto-oncogenes are expressed in neurons. The research has implications for reproductive neuroendocrinology as well as for cancer, since understanding proto-oncogene expression in normal cells during changes in physiology may provide clues as to how this regulation becomes aberrant.