Naegele J R, Arimatsu Y, Schwartz P, Barnstable C J
Laboratory of Neurobiology, Rockefeller University, New York, New York 10021.
J Neurosci. 1988 Jan;8(1):79-89. doi: 10.1523/JNEUROSCI.08-01-00079.1988.
VC1.1 is a monoclonal antibody generated against cat area 17, which selectively outlines subsets of cortical neurons (Arimatsu et al., 1987). This study was conducted to determine the ultrastructural distribution of the VC1.1 antigen and to identify the particular subclasses of cortical neurons that were labeled. In the light microscope, VC1.1 delineated the surfaces of neurons located mainly in layer IV but also in other layers. The staining surrounded neuronal cell bodies and dendrites in a periodic or meshwork pattern but did not label axons. VC1.1-labeled neurons were morphologically heterogeneous and included multipolar, bipolar, and bitufted classes. In the electron microscope, VC1.1 immunoreactivity surrounded presynaptic membranes of terminal boutons and intersynaptic sections of postsynaptic membranes, but was not present within terminal boutons or synaptic clefts. Both asymmetric and symmetric synapses were immunoreactive. Labeling was also observed intracellularly on VC1.1-outlined neurons, associated with perisynaptic portions of plasma membranes. Tract-tracing methods were used in conjunction with immunocytochemistry to determine whether VC1.1 identified projection neurons, local circuit neurons, or a combination of both types. Layer V and VI corticogeniculate and corticotectal projection neurons were retrogradely labeled with rhodamine fluorescent latex microspheres. In a large sample of retrogradely labeled neurons, none were VC1.1-positive, suggesting that VC1.1 stained a population of local circuit neurons. Additional immunocytochemical double-labeling studies with an antiserum to GABA and VC1.1, revealed that VC1.1-positive neurons were immunoreactive to GABA. These were a major subset of the GABAergic neurons in area 17 and tended to have medium to large cell bodies. It is concluded that VC1.1 identifies a new, immunologically distinct subset of GABAergic neurons in area 17. The restricted distribution of this antigen on perisynaptic portions of GABA-containing cells and surrounding terminal boutons onto these cells suggests that this antigen may play an important role in inhibitory cortical circuits.
VC1.1是一种针对猫17区产生的单克隆抗体，它能选择性勾勒出皮质神经元的亚群（有松等人，1987年）。本研究旨在确定VC1.1抗原的超微结构分布，并识别被标记的皮质神经元的特定亚类。在光学显微镜下，VC1.1勾勒出主要位于第IV层但也存在于其他层的神经元表面。染色以周期性或网状模式围绕神经元胞体和树突，但不标记轴突。VC1.1标记的神经元在形态上具有异质性，包括多极、双极和双簇状类型。在电子显微镜下，VC1.1免疫反应性围绕终末小体的突触前膜和突触后膜的突触间部分，但不存在于终末小体或突触间隙内。不对称和对称突触均具有免疫反应性。在VC1.1勾勒出轮廓的神经元内也观察到标记，与质膜的突触周围部分相关。使用示踪方法结合免疫细胞化学来确定VC1.1识别的是投射神经元、局部回路神经元还是这两种类型的组合。用罗丹明荧光乳胶微球逆行标记第V层和第VI层的皮质膝状体和皮质顶盖投射神经元。在大量逆行标记的神经元样本中，没有一个是VC1.1阳性的，这表明VC1.1标记的是一群局部回路神经元。用抗GABA血清和VC1.1进行的额外免疫细胞化学双重标记研究表明，VC1.1阳性神经元对GABA具有免疫反应性。这些是17区GABA能神经元的主要亚群，往往具有中等至大的细胞体。得出的结论是，VC1.1识别出17区中一个新的、在免疫上不同的GABA能神经元亚群。该抗原在含GABA细胞的突触周围部分以及围绕这些细胞的终末小体上的局限性分布表明，该抗原可能在抑制性皮质回路中起重要作用。
