Connection analysis of corticostriatal cells

为了揭示向纹状体产生皮质输出的皮质内回路，我们确定了额叶皮质中具有许多皮质纹状体细胞的神经元类型，1.投射到纹状体的锥体细胞的形态学和生理学鉴定：荧光逆行标记发现投射到脑桥核的锥体细胞[皮质桥脑（corticopontine，CPn）细胞]和对侧纹状体[交叉皮质纹状体（CCS）细胞]是不同的群体，在初始阶段的双重放电反应去极化被发现只在CPn细胞。非锥体细胞亚型的客观鉴定及形态定量分析：从神经元放电和轴突的角度定量鉴定了非锥体细胞亚型 ...更多信息 并对它们的轴突分支和突触终扣的形成以及树突的分支和棘的分布进行了定量分析。分支间距离和突触终接距离是独立确定的，并且每个亚型都有这些方法的独特组合。根据索马胞体发出的一级树突数、树突的延伸方向、平均分支长度和棘密度，将非锥体细胞分为3种树突型。棘密度以Martinotti细胞最高。3.锥体细胞与非锥体细胞之间的突触联系我们采用配对记录法，对锥体细胞与非锥体细胞之间的突触联系进行了研究。比较了从快速尖峰或CCS细胞到CCS细胞的突触电流。在兴奋性连接中，电流幅值依赖于接触部位的数目，而在抑制性连接中，电流幅值强烈依赖于接触部位。少

To reveal the intracortical circuitry of generating cortical outputs to the striatum, we identified neuron types in the frontal cortex with many corticostriatal cells, and analyzed their morphologies and synaptic connections quantitatively.1.Morphological and physiological identification of pyramidal cells projecting the striatum.By fluorescent retrograde labeling we found that pyramidal cells projecting to the pontine nuclei [corticopontine (CPn) cells] and the contralateral striatum [crossed corticostriatal (CCS) cells] were separate populations, and that doublet firing at the initial phase in response to depolarization was found only in CPn cells. The apical tufts developed more in CPn cells than CCS cells, but the tuft structures were variable among CCS cells, dependent on the soma location.2.Objective identification of nonpyramidal cell subtypes and quantitative analysis of their morphologies.We identified nonpyramidal cells subtypes quantitatively from the firing and axonal arbor … More izing patterns, and analyzed their axonal branching and synaptic bouton formation as well as the dendritic branching and spine distribution quantitatively. The inter-branch and synaptic bouton distances were determined independently, and each subtypes had a unique combination of these means. Nonpyramidal cells were divided into three dendritic patterns by the primary dendrite number issuing from a soma, their extending direction, mean branch length and spine density. The spine density was highest in Martinotti cells. Composition of morphological spine types was also different among subtypes.3.Synaptic connections among identified pyramidal and nonpyramidal cell subtypes.We investigated the synaptic connections patterns among cells identified as above, using paired recording in vitro slice preparation and morphological reconstruction of intracellular stained cells. The synaptic currents from fast-spiking or CCS cells to CCS cells were compared. The current amplitude was dependent on the number of contact sites in excitatory connections, but strongly dependent on the contact locations in inhibitory connections. Less