Goldman-Rakic P S, Leranth C, Williams S M, Mons N, Geffard M
Section of Neuroanatomy, Yale School of Medicine, New Haven, CT 06510.
Proc Natl Acad Sci U S A. 1989 Nov;86(22):9015-9. doi: 10.1073/pnas.86.22.9015.
Dopamine (DA)-containing projections to the cerebral cortex are considered to play an important role in cognitive processes. Using a recently developed monoclonal antiserum directed against DA and an antibody directed against tyrosine hydroxylase in combination with Golgi impregnation and electron microscopy, we have observed that DA and tyrosine hydroxylase afferents establish symmetric membrane specializations with the soma, dendritic shafts, and spines of identified pyramidal cells in the prefrontal, cingulate, and motor cortex of primates. The axospinous contacts invariably formed part of a synaptic complex in which the dendritic spine of a pyramidal neuron was the target of both a DA-positive symmetric and an unlabeled asymmetric bouton. This arrangement allows direct DA modulation of the overall excitability of cortical projection neurons by altering local spine responses to excitatory inputs.
向大脑皮层投射的含多巴胺（DA）纤维被认为在认知过程中起重要作用。利用最近研制出的针对多巴胺的单克隆抗血清和针对酪氨酸羟化酶的抗体，结合高尔基染色法和电子显微镜技术，我们观察到，在灵长类动物的前额叶、扣带回和运动皮层中，多巴胺能和酪氨酸羟化酶阳性传入纤维与已鉴定的锥体细胞的胞体、树突干和树突棘形成了对称性的膜特化结构。轴突-树突棘接触总是形成突触复合体的一部分，在该复合体中，锥体细胞的树突棘是多巴胺阳性对称终末和未标记的不对称终末的共同靶点。这种结构使得多巴胺能够通过改变局部树突棘对兴奋性输入的反应，直接调节皮层投射神经元的整体兴奋性。
