Individual differences in maternal behavior in the rat

描述(由申请人提供)：母性行为的变化调节神经系统的发展，神经系统调节大鼠对压力的行为和内分泌反应的表达(参见Liu等人，1997年；Caldji等人，1998年PNAS)，以及母性行为(Francis等人，1999)。最近的发现(Francis等人，1999)表明，这些影响提供了一个特征从一代到下一代的行为传递的例子。下一个问题是关于母亲行为的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以及对压力的行为和内分泌反应的发展之间存在关系的神经生物学基础。驱动这项拨款的假说试图从恐惧的神经系统以及调节父母照顾的神经系统的发展角度来解释这些环境影响。这里提出的实验旨在解决这一假说的三个主要原则：1)母体行为的个体差异是通过行为传递模式遗传的；2)母体护理的差异与调节母体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-催产素的相互作用，而雌激素-催产素相互作用反过来又调节多巴胺活动。具体地说，我们认为母爱影响视前内侧区域雌激素受体基因表达的发展，增加了该结构对催产素的敏感性，并为随后催产素诱导伏隔核多巴胺释放的增加提供了基础。

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.