Jaeger C, Gonzalo Ruiz A, Llinás R
Department of Physiology and Biophysics, New York University Medical Center, NY 10016.
Brain Res Bull. 1989 Jun;22(6):981-91. doi: 10.1016/0361-9230(89)90010-5.
Morphological methods were used to study the plasticity of target-deprived mammalian dopaminergic (DA) neurons. Slices of substantia nigra (SN) were taken from the midbrain of rats aged one to twelve days, and cultured for one to two weeks. Localization of tyrosine hydroxylase (TH) was used to examine the distribution and shapes of DA neurons. Histochemical staining for acetylcholinesterase (AChE) was carried out to estimate both survival and biosynthesis of SN neurons. We found that some DA neurons can survive in vitro without their usual target neurons. This was demonstrated by injecting rhodamine-conjugated microspheres (RD) into the caudate putamen, a SN target area, at 6 to 8 days prior to culturing. RD-labeled cells survived in SN cultures and some of them were doubly labeled with AChE. TH neurons had different shapes and their axon terminals formed close contacts with adjacent nondopaminergic neurons. These findings suggest that a subset of DA neurons may switch targets, but the majority of them require target interactions with the caudate putamen for survival in vitro.
采用形态学方法研究了靶剥夺的哺乳动物多巴胺能（DA）神经元的可塑性。从1至12日龄大鼠的中脑取出黑质（SN）切片，并培养1至2周。利用酪氨酸羟化酶（TH）的定位来检查DA神经元的分布和形态。进行乙酰胆碱酯酶（AChE）的组织化学染色以评估SN神经元的存活和生物合成。我们发现一些DA神经元在没有其通常的靶神经元的情况下能够在体外存活。这通过在培养前6至8天将罗丹明偶联微球（RD）注入尾状壳核（一个SN靶区）来证明。RD标记的细胞在SN培养物中存活，其中一些细胞被AChE双重标记。TH神经元具有不同的形态，并且它们的轴突终末与相邻的非多巴胺能神经元形成紧密接触。这些发现表明一部分DA神经元可能会转换靶标，但它们中的大多数在体外存活需要与尾状壳核进行靶标相互作用。
