McDonald A J, Mascagni F
Department of Cell Biology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208, USA.
Neuroscience. 2001;105(3):681-93. doi: 10.1016/s0306-4522(01)00214-7.
The basolateral amygdala contains subpopulations of non-pyramidal neurons that express the calcium-binding proteins parvalbumin, calbindin-D28k (calbindin) or calretinin. Although little is known about the exact functions of these proteins, they have provided useful markers of specific neuronal subpopulations in studies of the neuronal circuitry of the cerebral cortex and other brain regions. The purpose of the present study was to investigate whether basolateral amygdalar non-pyramidal neurons containing parvalbumin, calbindin, or calretinin exhibit immunoreactivity for GABA, and to determine if calretinin is colocalized with parvalbumin or calbindin in the rat basolateral amygdala. Pyramidal neurons were distinguished from non-pyramidal neurons on the basis of staining intensity. Using immunofluorescence confocal laser scanning microscopy, as well as the 'mirror technique' on immunoperoxidase-stained sections, it was found that there was virtually no colocalization of calretinin with parvalbumin or calbindin, but that the great majority of basolateral amygdalar non-pyramidal neurons containing parvalbumin, calbindin, or calretinin exhibited GABA immunoreactivity. Calbindin-positive neurons constituted almost 60% of the GABA-containing population in both subdivisions of the basolateral nucleus and more than 40% of the GABA-containing population in the lateral nucleus. Parvalbumin-positive neurons constituted 19-43% of GABA-immunoreactive neurons in the basolateral amygdala, depending on the nucleus. Calretinin-positive non-pyramidal neurons constituted about 20% of the GABA-positive neuronal population in each nucleus of the basolateral amygdala. These findings indicate that non-pyramidal neurons containing parvalbumin, calbindin, or calretinin comprise the majority of GABA-containing neurons in the basolateral amygdala, and that the calretinin subpopulation is distinct from non-pyramidal subpopulations containing parvalbumin and calbindin. These separate neuronal populations may play unique roles in the inhibitory circuitry of the amygdala.
基底外侧杏仁核包含表达钙结合蛋白小白蛋白、钙结合蛋白-D28k（钙结合蛋白）或钙视网膜蛋白的非锥体神经元亚群。尽管对这些蛋白的确切功能了解甚少，但它们在大脑皮层和其他脑区神经回路的研究中为特定神经元亚群提供了有用的标记物。本研究的目的是调查含有小白蛋白、钙结合蛋白或钙视网膜蛋白的基底外侧杏仁核非锥体神经元是否表现出GABA免疫反应性，并确定钙视网膜蛋白在大鼠基底外侧杏仁核中是否与小白蛋白或钙结合蛋白共定位。根据染色强度将锥体神经元与非锥体神经元区分开来。使用免疫荧光共聚焦激光扫描显微镜以及免疫过氧化物酶染色切片上的“镜像技术”，发现钙视网膜蛋白与小白蛋白或钙结合蛋白几乎没有共定位，但绝大多数含有小白蛋白、钙结合蛋白或钙视网膜蛋白的基底外侧杏仁核非锥体神经元表现出GABA免疫反应性。在基底外侧核的两个亚区中，钙结合蛋白阳性神经元占含GABA群体的近60%，在外侧核中占含GABA群体的40%以上。小白蛋白阳性神经元占基底外侧杏仁核中GABA免疫反应性神经元的19%-43%，具体比例取决于核区。钙视网膜蛋白阳性非锥体神经元在基底外侧杏仁核的每个核区中约占GABA阳性神经元群体的20%。这些发现表明，含有小白蛋白、钙结合蛋白或钙视网膜蛋白的非锥体神经元构成了基底外侧杏仁核中含GABA神经元的大多数，并且钙视网膜蛋白亚群与含有小白蛋白和钙结合蛋白的非锥体亚群不同。这些独立的神经元群体可能在杏仁核的抑制性回路中发挥独特作用。
