Sesack S R, Bressler C N, Lewis D A
Department of Neuroscience, University of Pittsburgh, PA 15260, USA.
Neurosci Lett. 1995 Nov 10;200(1):9-12. doi: 10.1016/0304-3940(95)12076-g.
Dopamine terminals in the monkey prefrontal cortex (PFC) synaptically target the distal dendrites of both pyramidal cells and GABA interneurons. We sought to determine whether the latter input includes the innervation of interneurons that utilize calretinin (CalR) as a calcium-binding protein. Sections through prefrontal area 9 of cynomolgus monkeys were processed by immunoperoxidase for tyrosine hydroxylase (TH) to label dopamine varicosities and by pre-embedding immunogold for CalR. Electron microscopic examination of layers 1-3 revealed numerous TH-immunoreactive (TH-ir) terminals, but few were located in the vicinity of CalR-ir dendrites. Although close appositions were sometimes detected between these labeled processes, no synaptic inputs from TH-ir terminals to CalR-ir dendrites were observed. However, in adjacent sections from the same animals, TH-ir terminals were observed to synapse on GABA-ir dendrites. These findings suggest that dopamine afferents to the monkey PFC target the subclasses of GABA interneurons that do not contain CalR.
猴子前额叶皮质（PFC）中的多巴胺终末通过突触作用于锥体细胞和GABA能中间神经元的远端树突。我们试图确定后者的输入是否包括对利用钙视网膜蛋白（CalR）作为钙结合蛋白的中间神经元的支配。对食蟹猴前额叶9区的切片进行免疫过氧化物酶处理以标记多巴胺膨体，并用预包埋免疫金法标记CalR。对1-3层进行电子显微镜检查发现大量酪氨酸羟化酶免疫反应性（TH-ir）终末，但很少位于CalR-ir树突附近。虽然有时在这些标记的突起之间检测到紧密并列，但未观察到TH-ir终末到CalR-ir树突的突触输入。然而，在同一动物的相邻切片中，观察到TH-ir终末与GABA-ir树突形成突触。这些发现表明，猴子PFC的多巴胺传入纤维靶向不包含CalR的GABA能中间神经元亚类。
