Oliver D L, Winer J A, Beckius G E, Saint Marie R L
Department of Anatomy, University of Connecticut Health Center, Farmington 06030-3405.
J Comp Neurol. 1994 Feb 1;340(1):27-42. doi: 10.1002/cne.903400104.
The goal of the present study was to provide a comprehensive and quantitative description of neurons immunoreactive for gamma-aminobutyric acid (GABA) in the inferior colliculus (IC) of the cat. Neurons were investigated with two different antisera and two different incubation methods. Free-floating frozen or vibratome-cut sections were incubated either with an antiserum to glutamic acid decarboxylase (GAD) or to GABA conjugated to protein with glutaraldehyde. Additional 1.5-microns-thick sections were incubated with the GABA antiserum after embedding and removal of the plastic. Quantitative data were obtained from much of this material. Despite the use of these different antisera and reaction methods, the results obtained were remarkably similar. The results show that GAD- or GABA-positive neurons represent a significant population of cells in the central nucleus of the IC, up to 20% of the neurons. Most of these neurons have large or medium-sized perikarya. In contrast, immunonegative neurons are medium-sized or small. Many GABA-positive neurons had proximal dendrites or somata oriented in parallel to the fibrodendritic laminae of the central nucleus and are presumed to be disc-shaped neurons. Other have an orthogonal orientation and are presumed to be stellate cells. Large GABA-positive neurons form two groups, those with many axosomatic endings and those with few. Collectively, these observations suggest that there are several types of GABAergic neuron in the central nucleus and, by extension, that these may participate in many types of inhibitory circuits.
本研究的目的是对猫下丘（IC）中γ-氨基丁酸（GABA）免疫反应性神经元进行全面定量描述。使用两种不同的抗血清和两种不同的孵育方法对神经元进行研究。游离漂浮的冰冻切片或振动切片机切割的切片，分别用抗谷氨酸脱羧酶（GAD）抗血清或戊二醛结合蛋白的GABA抗血清孵育。另外，将包埋并去除塑料后的1.5微米厚切片用GABA抗血清孵育。从大量此类材料中获得了定量数据。尽管使用了这些不同的抗血清和反应方法，但所得结果非常相似。结果表明，GAD或GABA阳性神经元在IC中央核中占相当大的细胞群体，高达神经元总数的20%。这些神经元大多具有大或中等大小的胞体。相比之下，免疫阴性神经元为中等大小或小。许多GABA阳性神经元的近端树突或胞体与中央核的纤维树突板平行排列，推测为盘状神经元。其他神经元则呈正交排列，推测为星状细胞。大型GABA阳性神经元形成两组，一组有许多轴体终末，另一组则很少。总体而言，这些观察结果表明，中央核中有几种类型的GABA能神经元，进而表明它们可能参与多种类型的抑制性回路。
