Choi H K, Won L, Roback J D, Wainer B H, Heller A
Department of Pharmacological and Physiological Sciences, University of Chicago 60637.
Proc Natl Acad Sci U S A. 1992 Oct 1;89(19):8943-7. doi: 10.1073/pnas.89.19.8943.
MN9D is an immortalized dopamine-containing neuronal hybrid cell line. When MN9D cells were coaggregated with primary embryonic cells of optic tectum, a brain region that does not receive a dopaminergic innervation, there was a marked reduction in their dopamine content, tyrosine hydroxylase immunoreactivity, and tyrosine hydroxylase mRNA. Similar reductions in dopamine content were produced by coaggregation with cells from embryonic thalamus, another brain region devoid of dopaminergic innervation. Coaggregation of MN9D cells with dopaminoceptive cells from the corpus striatum or the cortex did not have a demonstrable stimulatory effect on the dopamine content of MN9D cells. The decrease in MN9D dopamine content produced by optic tectum cells was not reversed by addition of corpus striatum cells. Thus, the MN9D hybrid cells are able to respond to an inhibitory factor(s) from cells derived from brain areas that are not targets for dopaminergic neurons. Catecholamine-producing PC12 cells did not respond in a similar manner, suggesting that the response of MN9D cells is a function of their mesencephalic origin. Given the selective response of MN9D cells to different brain cell populations, this hybrid cell line should facilitate investigations of cell-cell interactions in the central nervous system that may be involved in the expression of neurotransmitter phenotype and establishment of specific neuronal connections.
MN9D是一种永生化的含多巴胺神经元杂交细胞系。当MN9D细胞与视顶盖的原代胚胎细胞（视顶盖是一个不接受多巴胺能神经支配的脑区）共聚集时，其多巴胺含量、酪氨酸羟化酶免疫反应性和酪氨酸羟化酶mRNA均显著降低。与来自胚胎丘脑（另一个没有多巴胺能神经支配的脑区）的细胞共聚集也会使多巴胺含量产生类似的降低。MN9D细胞与纹状体或皮质的多巴胺感受性细胞共聚集，对MN9D细胞的多巴胺含量没有明显的刺激作用。视顶盖细胞导致的MN9D多巴胺含量降低，不会因添加纹状体细胞而逆转。因此，MN9D杂交细胞能够对来自非多巴胺能神经元靶脑区的细胞产生的抑制因子作出反应。产生儿茶酚胺的PC12细胞没有类似的反应，这表明MN9D细胞的反应是其中脑起源的一种功能。鉴于MN9D细胞对不同脑细胞群体的选择性反应，这种杂交细胞系应有助于研究中枢神经系统中可能参与神经递质表型表达和特定神经元连接建立的细胞间相互作用。
