Laboratoire de Neurobiologie et Diversité Cellulaire, CNRS UMR7637, Ecole Supérieure de Physique et de Chimie Industrielles, 75005 Paris, France.
Cereb Cortex. 2013 Feb;23(2):423-41. doi: 10.1093/cercor/bhs032. Epub 2012 Feb 22.
Neocortical layer VI modulates the thalamocortical transfer of information and has a significant impact on sensory processing. This function implicates local γ-aminobutyric acidergic (GABAergic) interneurons that have only been partly described at the present time. Here, we characterized 85 layer VI GABAergic interneurons in acute slices of mouse somatosensory barrel cortex, using whole-cell current-clamp recordings, single-cell reverse transcription-polymerase chain reaction, and biocytin labeling followed by Neurolucida reconstructions. Unsupervised clustering based on electrophysiological molecular and morphological properties disclosed 4 types of interneurons. The 2 major classes were fast-spiking cells transcribing parvalbumin (PV) (51%) and adapting interneurons transcribing somatostatin (SOM) (26%). The third population (18%) transcribed neuropeptide Y (NPY) and appeared very similar to neurogliaform cells. The last class (5%) was constituted by well-segregated GABAergic interneurons transcribing vasoactive intestinal peptide (VIP). Using transgenic mice expressing GFP under the control of the glutamic acid decarboxylase 67k (GAD67) promoter, we investigated the densities of GABAergic cells immunolabeled against PV, SOM, VIP, and NPY through the depth of layer VI. This analysis revealed that PV and NPY translating interneurons concentrate in the upper and lower parts of layer VI, respectively. This study provides an extensive characterization of the properties of layer VI interneurons.
新皮层 VI 层调节丘脑皮质信息传递，对感觉处理有重要影响。这种功能暗示了局部γ-氨基丁酸能（GABAergic）中间神经元的存在，目前这些中间神经元只得到了部分描述。在这里，我们使用全细胞膜片钳记录、单细胞逆转录聚合酶链反应（reverse transcription-polymerase chain reaction，RT-PCR）和生物素标记后进行神经Lucida 重建，对急性小鼠体感皮层脑片的 85 个 VI 层 GABAergic 中间神经元进行了特征描述。基于电生理、分子和形态特性的无监督聚类揭示了 4 种中间神经元类型。主要的 2 类是转录 parvalbumin（PV）的快速放电细胞（51%）和转录 somatostatin（SOM）的适应中间神经元（26%）。第三类（18%）转录神经肽 Y（NPY），与神经胶质样细胞非常相似。最后一类（5%）由分化良好的转录血管活性肠肽（vasoactive intestinal peptide，VIP）的 GABAergic 中间神经元组成。我们使用表达 GFP 的转基因小鼠，该 GFP 由谷氨酸脱羧酶 67k（glutamic acid decarboxylase 67k，GAD67）启动子控制，通过 VI 层的深度研究了针对 PV、SOM、VIP 和 NPY 免疫标记的 GABAergic 细胞的密度。该分析表明，PV 和 NPY 翻译中间神经元分别集中在 VI 层的上部和下部。这项研究提供了对 VI 层中间神经元特性的广泛描述。
