CONTROL OF NEUROTRANSMITTER PHENOTYPE IN THE EMBRYO

在我的实验室进行的研究已经证明了在大鼠中存在 胚胎细胞群-位于肠间充质和 几个颅感觉神经节和背根神经节， 表达儿茶酚胺（CA）表型的方面（14-19）。 细胞 发育中的肠道，例如，具有酪氨酸羟化酶（T-OH）、多巴胺 B-羟化酶、CA荧光和特异性高亲和力摄取 CA的过程。 此外，他们对母亲的高血压有反应。 糖皮质激素（17，18）和神经生长因子（NGF，21，177） 随着T-OH水平的增加和CA性状的延长表达。 利用这些短暂的CA人群，我们计划调查因素 控制神经递质表型的维持（或损失） 表情 具体而言，该计划是1）研究体内和 体外糖皮质激素对肠细胞作用的位点，2）确定 通过药理学延长CA在肠道中的瞬时CA细胞的命运 性状和其他NT的同时检测已知存在于 3）确定瞬时神经递质的功能 在胚胎肠中的表达，4）决定肠的容量 间充质支持CA性状，和5）检查短暂的T-OH阳性 颅感觉神经节中的细胞的表型命运和 在体内和体外对激素和环境因素的反应。

Studies performed in my laboratory have documented the existence in rat embryos of cell populations -- located in intestinal mesenchyme and in several cranial sensory and dorsal root ganglia -- which transiently express aspects of the catecholamine (CA) phenotype (14-19). Cells in developing gut, e.g., possess tyrosine hydroxylase (T-OH), dopamine B-hydroxylase, CA fluorescence, and a specific, high-affinity uptake process for CA's. In addition, they respond to elevated maternal glucocorticoid hormones (17, 18) and nerve growth factor (NGF, 21, 177) with increased levels of T-OH and a prolonged expression of CA traits. Utilizing these transiently CA populations we plan to investigate factors which control the maintenance (or loss) or neurotransmitter phenotypic expression. Specifically, the plan is to 1) investigate both in vivo and in vitro the site of glucocorticoid action on gut cells, 2) determine the fate of transiently CA cells in gut by pharmacological prolongation of CA traits and simultaneous detection of other NT's known to be present in adult gut, 3) determine the function of transient neurotransmitter expression in embryonic intestine, 4) determine the capacity of intestinal mesenchyme to support CA traits, and 5) examine transiently T-OH-positive cells in cranial sensory ganglia with respect to phenotypic fate and response to hormonal and environmental factors both in vivo and in vitro.