Thejomayen D M, Matsubara J A
Department of Ophthalmology, University of British Columbia, Vancouver, Canada.
Cereb Cortex. 1993 Sep-Oct;3(5):442-53. doi: 10.1093/cercor/3.5.442.
The intrinsic, horizontally projecting neurons in visual cortex are organized into discrete clusters, or patches. While earlier studies focused on the organization of the patches and their relationship to functional properties, such as orientation tuning and binocularity, little is known about the detailed morphology of the neurons in these patches. We retrogradely labeled patches of local, intracortical neurons (local patch neurons) by in vivo injections of fluorescent dextrans into area 18, then iontophoresed Lucifer yellow into prelabeled cells in lightly fixed cortical slices, and examined the dendritic morphology of local patch neurons in layer 2/3 of area 18 by confocal laser scanning microscopy. Most of the neurons we examined were spiny pyramidal neurons, including modified pyramids, small to moderately large standard pyramids, and star pyramids. Smooth, multipolar cells of the basket and bipolar cell types were also present. The basal dendritic trees of more than 60% of the local patch pyramidal neurons in layer 2/3 displayed mediolaterally elongated dendritic fields. This finding appears to be specific for pyramidal neurons, as our sample of smooth, multipolar neurons did not show this trend.
视觉皮层中内在的水平投射神经元被组织成离散的簇或斑块。虽然早期研究聚焦于这些斑块的组织及其与功能特性（如方向调谐和双眼视）的关系，但对于这些斑块中神经元的详细形态却知之甚少。我们通过在活体中将荧光葡聚糖注射到18区，逆行标记局部皮质内神经元的斑块（局部斑块神经元），然后在轻度固定的皮质切片中对预先标记的细胞进行离子电泳注入路西法黄，并通过共聚焦激光扫描显微镜检查18区第2/3层局部斑块神经元的树突形态。我们检查的大多数神经元是有棘锥体神经元，包括改良锥体神经元、小到中等大小的标准锥体神经元和星形锥体神经元。也存在篮状细胞和双极细胞类型的平滑多极细胞。第2/3层中超过60%的局部斑块锥体神经元的基底树突显示出沿内外侧拉长的树突野。这一发现似乎是锥体神经元特有的，因为我们的平滑多极神经元样本未显示出这种趋势。
