Pyramidal neuron local axon terminals in monkey prefrontal cortex: Differential targeting of subclasses of GABA neurons
Pyramidal neuron local axon terminals in monkey prefrontal cortex: Differential targeting of subclasses of GABA neurons
复制标题
DOI：
10.1093/cercor/13.5.452
复制
发表时间：
2003-05-01
期刊：
影响因子：
3.7
通讯作者：
Lewis, DA
中科院分区：
文献类型：
--
作者：
Melchitzky, DS;Lewis, DA
在猴的前额叶皮质(PFC)，类似于50%的锥体神经元的局部轴突终末与GABA神经元的树突形成突触。GABA神经元的亚类可以通过存在不同的钙结合蛋白来区分。例如，在猴PFC中，含有小白蛋白(PV)的细胞占GABA神经元的25%，主要分布在3b-4层，而在第2-3a层密度最大的含有Calretinin(CR)的细胞占GABA神经元的50%。因此，为了确定猴PFC区9区锥体神经元局部轴突侧支的树突靶点的细胞类别和板层特异性，我们对顺行示踪剂标记的局部轴突终末、生物素标记的葡聚糖胺以及PV或CR的树突免疫反应(IR)进行了超微结构分析。在3b层，大多数局部轴突终末以PV-IR树突干为靶点，而CR-IR树突干为少见靶点。这种不同的靶向也存在于第2-3a层，尽管它不那么明显。此外，PV-IR树突的兴奋性输入密度显著高于CR-IR树突。这些结果表明，对锥体神经元有强烈抑制作用的含PV中间神经元，选择性地被猴PFC颗粒上锥体神经元兴奋性局部轴突终末靶向。这些联系可能为工作记忆中锥体神经元和快速放电的GABA神经元的协调活动提供了解剖学基础。
In monkey prefrontal cortex (PFC), similar to50% of the local axon terminals of pyramidal neurons form synapses with the dendritic shafts of GABA neurons. Subclasses of GABA neurons can be distinguished by the presence of different calcium-binding proteins. For example, in monkey PFC, parvalbumin (PV)-containing cells comprise similar to25% of GABA neurons and are predominantly located in layers 3b-4, whereas calretinin (CR)-containing cells, which are present in greatest density in layers 2-3a, constitute 50% of GABA neurons. Consequently, in order to determine the cell class and laminar specificity of the dendritic targets of pyramidal neuron local axon collaterals in monkey PFC area 9, we conducted ultrastructural analyses of local axon terminals labeled with the anterograde tracer, biotinylated dextran amine, and dendrites immunoreactive (IR) for PV or CR. In layer 3b, the majority of the local axon terminals targeted PV-IR dendritic shafts, whereas CR-IR dendritic shafts were targeted infrequently. This differential targeting was also present in layers 2-3a, although it was less pronounced. In addition, PV-IR dendrites had a significantly greater density of excitatory inputs than did CR-IR dendrites. These findings indicate that PV-containing interneurons, which have a potent inhibitory effect on pyramidal neurons, are selectively targeted by the excitatory local axon terminals of supragranular pyramidal neurons in monkey PFC. These connections may provide the anatomical substrate for the coordinated activity of pyramidal neurons and fast-spiking GABA neurons during working memory.