Individual differences in maternal behavior in the rat

描述（由申请人提供）：母体行为的变化调节神经系统的发育，所述神经系统介导大鼠对应激的行为和内分泌反应的表达（参见Liu等人，Science，1997; Caldji等人，1998 PNAS），以及母性行为（弗朗西斯等人，1999）。最近的研究结果（弗朗西斯等人，1999年）表明，这些影响提供了一个例子，从一代到下一代的性状的行为传递。下一个问题是关于母性行为中这些个体差异的起源。 我们在这些研究中的主要目标是了解环境刺激，父母行为的个体差异和对压力的行为和内分泌反应的发展之间存在的关系的神经生物学基础。推动这项研究的假设试图从神经系统的发展方面解释这些环境效应，这些神经系统是恐惧的基础，也是父母照顾的中介。这里提出的实验旨在解决这一假设的三个主要原则：1）母性行为的个体差异是通过行为传播模式遗传的，2）母性护理的变化与介导母性行为表达的神经系统的个体差异有关，3）这些系统的关键特征涉及雌激素-催产素相互作用，进而调节多巴胺活性。具体来说，我们建议，产妇护理的发展影响雌激素受体基因的表达在内侧视前区，增加敏感性，该结构的催产素，并提供了一个基础，随后催产素诱导的多巴胺释放增加在延髓核。

DESCRIPTION (provided by applicant): Variations in maternal behavior regulate the development of neural systems that mediate the expression of behavioral and endocrine responses to stress in the rat (see Liu et al., Science, 1997; Caldji et al., 1998 PNAS), as well as maternal behavior (Francis et al, 1999). Recent findings (Francis et al, 1999) suggest that these effects provide an example of the behavioral transmission of traits from one generation to the next. The next question concerns the origins of these individual differences in maternal behavior. Our primary goal in these studies is to understand the neurobiological basis for the relationships that exist between environmental stimuli, individual differences in parental behavior and the development of behavioral and endocrine responses to stress. The hypothesis which drives this grant attempts to explain these environmental effects in terms of the development of neural systems underlying fearfulness as well as those which mediate parental care. The experiments proposed here are designed to address the three principle tenets of this hypothesis: 1) that individual differences in maternal behavior are inherited via a behavioral mode of transmission, 2) that variations in maternal care are associated with individual differences in neural systems that mediate the expression of maternal behavior, and 3) that the critical features of these systems involve estrogen-oxytocin interactions which, in turn, regulate dopamine activity. Specifically we propose that maternal care influences the development of estrogen receptor gene expression in the medial preoptic area, increasing the sensitivity of this structure to oxytocin and providing a basis for subsequent oxytocin-induced increases in dopamine release in the nucleus accumbens.