鸡后根神经节多巴胺细胞在体及体外培养中的免疫细胞化学观察

应用免疫细胞化学PAP法,研究了鸡胚和雏鸡后根神经节细胞内多巴胺递质的表现与胚胎发育过程中的变化,并在细胞培养条件下研究了周围靶组织——皮肤对后根节细胞胚胎发育的影响。鸡后根节细胞内多巴胺的免疫反应最先出现于E_(10),只占后根节细胞的0.8%,E_(18)时达5.6%,出壳后雏鸡为8.6%。在鸡后根节内,多巴胺免疫反应阳性细胞主要为较大的A类细胞,和极少较小的B类细胞。免疫反应阳性的周围神经末梢位于皮肤和交感干内。当取自E_9的鸡胚后根节细胞经7天培养后,部分神经细胞出现多巴胺免疫反应阳性;而取自E_6的鸡胚后根节细胞虽经10天培养后仍为免疫反应阴性;然而,将取自E_6后根节细胞与皮肤组织联合培养10天后,少量神经细胞及轴突出现多巴胺免疫阳性反应。作者认为:鸡后根节多巴胺细胞在胚胎时期的发育有赖于周围靶组织的作用。

EXPRESSION OF DOPAMINE IMMUNOREACTIVITY BY CHICK DORSAL ROOT GANGLIA IN VIVO AND IN VITRO

The expression of dopamine by primary sensory neurons and their peripheral projections was studied in the chick dorsal root ganglion (DRG) by means of immunocyto-chemical procedures in vivo and in vitro. Within the chick lumbo-sacral dorsal root ganglion cells, dopamine immunoreactivity was first expressed by 0.8% of cells at E10 and reached a percentage of 5.6 on E18. After hatching, 8.6% of cells, belonging to both the A and B classes of sensory neurons exhibited a clear immunostaining. According to the immunostaining of nerve terminals located in various peripheral target tissues, these immunoreactive neurons were responsible, at least in part, for the sensory innervation of the skin and paravertebral ganglia. In the DRG cells cultured from chick embryo E9, after the formation of sensory connections with peripheral targets, some sensory neurons were immunostained by dopamine antiserum after 7 days of culture. However, the DRG cells cultured from E6, prior to the formation of specific connection with peripheral target tissues were devoid of any dopamine immunoreactive neurons after 10 days of culture. Moreover, when the E6 DRG cells were co-cultured with skin tissues for 10 days, some of the DRG cells were immunostained by dopamine antiserum, and some connections of terminal fibers of sensory neurons with skin tissue were observed occasionally. In conclusion, the initiation of dopamine expression by chick DRG cells seems to be dependent on skin peripheral target tissues.