Jinno Shozo, Kosaka Toshio
Kyushu University, Department of Anatomy & Neurobiology, Graduate School of Medical Sciences, 3-1-1 Maidashi, Migashi-ku, 812-8582 Fukuoka, Japan.
J Comp Neurol. 2002 Jul 15;449(1):1-25. doi: 10.1002/cne.10251.
We examined the expression of calcium binding proteins parvalbumin (PV), calretinin (CR), and calbindin D28K (CB), and neuronal nitric oxide synthase (nNOS) in gamma-aminobutyric acid (GABA)ergic neurons of the mouse hippocampus, with particular reference to areal and dorsoventral differences. First, we estimated the colocalization of the calcium binding proteins and nNOS. GABAergic neurons containing both PV and nNOS, i.e., PV-immunoreactive (-IR)/nNOS-IR neurons, were rare in Ammon's horn but frequent in the dentate gyrus (DG). CR-IR/nNOS-IR neurons and CB-IR/nNOS-IR neurons were frequent in Ammon's horn but rare in the DG. In the entire hippocampus, the percentage of CR-IR neurons containing nNOS was significantly higher at the ventral level (44.3%) than at the dorsal level (17.0%). The percentage of CB-IR neurons containing nNOS was also significantly higher at the ventral level (42.3%) than at the dorsal level (29.3%). Next, we estimated the numerical densities (NDs) of calcium binding protein-containing GABAergic neurons. The ND of PV-IR neurons was comparable at the dorsal (1.16 x 10(3)/mm(3)) and ventral levels (1.23 x 10(3)/mm(3)), respectively. The ND of CR-IR neurons was less at the dorsal level (0.52 x 10(3)/mm(3)) than at the ventral level (0.64 x 10(3)/mm(3)). The ND of CB-IR neurons was also less at the dorsal level (0.91 x 10(3)/mm(3)) than at the ventral level (1.57 x 10(3)/mm(3)). Overall, approximately half of the GABAergic neurons contained one of the three calcium binding proteins (45% at the dorsal level and 47% at the ventral level). These data establish a baseline for examining potential roles of GABAergic neurons in hippocampal network activity in mice.
我们研究了钙结合蛋白小白蛋白（PV）、钙视网膜蛋白（CR）和钙结合蛋白D28K（CB）以及神经元型一氧化氮合酶（nNOS）在小鼠海马体γ-氨基丁酸（GABA）能神经元中的表达，特别关注区域和背腹差异。首先，我们估计了钙结合蛋白与nNOS的共定位情况。同时含有PV和nNOS的GABA能神经元，即PV免疫反应性（-IR）/nNOS-IR神经元，在海马角中很少见，但在齿状回（DG）中很常见。CR-IR/nNOS-IR神经元和CB-IR/nNOS-IR神经元在海马角中很常见，但在DG中很少见。在整个海马体中，含有nNOS的CR-IR神经元的百分比在腹侧水平（44.3%）显著高于背侧水平（17.0%）。含有nNOS的CB-IR神经元的百分比在腹侧水平（42.3%）也显著高于背侧水平（29.3%）。接下来，我们估计了含有钙结合蛋白的GABA能神经元的数值密度（NDs）。PV-IR神经元的ND在背侧（1.16×10³/mm³）和腹侧水平（1.23×10³/mm³）分别相当。CR-IR神经元的ND在背侧水平（0.52×10³/mm³）低于腹侧水平（0.64×10³/mm³）。CB-IR神经元的ND在背侧水平（0.91×10³/mm³）也低于腹侧水平（1.57×10³/mm³）。总体而言，大约一半的GABA能神经元含有三种钙结合蛋白中的一种（背侧水平为45%，腹侧水平为47%）。这些数据为研究GABA能神经元在小鼠海马体网络活动中的潜在作用奠定了基础。
