Analyses on the juxtaglomerular neurons of the olfactory bulb : 2 types of periglomerular cells

嗅球球旁神经元的分析：两种类型的球周细胞

基本信息

批准号：
20500309
负责人：
KOSAKA Katsuko
金额：
$ 2.91万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2010
项目状态：
已结题

项目摘要

In the olfactory bulb, the first center of the olfaction, the glomerulus is considered as a functional unit and thus to be important in the olfactory information processing. In the present study we examined following three points. (1) Do the periglomerular cells, type 1 and type 2, have axons? We applied multiple fluorescent immunostaining using antibodies of chemical markers for type 1 and 2 periglomerular cells as well as for axon initial segments, such as AnkyrinG, Nav, and βIV-spectrin. The confocal laser scanning observations revealed that large type of tyrosine hydroxylase (TH) positive GABAergic juxtaglomerular neurons, nitric oxide synthase (NOS) positive external tufted cells and short-axon cells expressing NOS, calbindin and parvalbumin (PV). However, most of Analyses on the juxtaglomerular neurons of the olfactory bulb : 2 types of periglomerular cells periglomerular cells did not show the chemically identified axon initial segments, indicating those periglomerular cells are … More anaxonic. (2) As well known TH positive GABAergic juxtaglomerular neurons are one of major groups of neurons generated even in adult period. On the other hand, there two types of TH positive neurons, large and small ones, and as we previously revealed the large type of TH positive neurons show long extending axonal processes to distant glomeruli making the inhibitory association system. In the present study we determined when both types of TH positive neurons are born and whether adult-generated TH positive neurons include both types. BrdU were injected at various developmental stages; prenatal period (E13, E17), neonate (P3) and juvenile or adult (P4w or 8w). This analysis revealed that both large and small TH positive neurons generated during prenatal and neonate periods. But only small type of TH positive neurons are adult-generated neurons. (3) We found particular axon initial segment-like or node of Ranvier-like sites "hot spots" on the dendritic segments of anaxonic PV positive GABAergic neurons in the external plexiform layer. These hot spots expressed chemical markers for axon initial segments and furthermore showed the ultrastructural feature characteristic to axon initial segment, membrane undercoating. Thus these hot spots are supposed to be the spike generating sites. Less

在嗅球（嗅觉的第一个中心）中，肾小球被认为是一个功能单位，因此在嗅觉信息处理中很重要。在本研究中，我们检查了以下三点（1）做肾小球周围细胞，类型。 1 型和 2 型，有轴突吗？我们使用化学标记物的抗体对 1 型和 2 型肾小球周围细胞以及轴突初始片段进行多重荧光免疫染色，例如AnkyrinG、Nav 和 βIV-血影蛋白共聚焦激光扫描观察显示，大类型酪氨酸羟化酶 (TH) 阳性 GABA 能球旁神经元、一氧化氮合酶 (NOS) 阳性外部簇状细胞和表达 NOS、钙结合蛋白和小清蛋白的短轴突细胞。 (PV) 然而，大多数对嗅球近球神经元的分析：2肾小球周围细胞的类型肾小球周围细胞没有显示出化学鉴定的轴突初始片段，表明这些肾小球周围细胞是轴突的 (2) 众所周知，TH 阳性 GABA 肾小球旁神经元是即使在成年期也会产生的主要神经元群体之一。另一方面，有两种类型的 TH 阳性神经元，大的和小的，正如我们之前揭示的，大类型的 TH 阳性神经元显示出长的轴突延伸到远处在本研究中，我们确定了两种类型的 TH 阳性神经元的出生时间以及成人产生的 TH 阳性神经元是否在不同的发育阶段（E13、E17）被注射。新生儿 (P3) 和青少年或成人 (P4w 或 8w) 该分析表明，在产前和新生儿期均产生了大和小的 TH 阳性神经元，但只有小型 TH 阳性神经元。 (3)我们在外部丛状层中轴突PV阳性GABA能神经元的树突节上发现了特定的轴突初始节段或Ranvier样节点“热点”，这些热点表达了轴突初始节段的化学标记。显示出轴突初始段、膜底涂层的超微结构特征，因此这些热点应该是尖峰产生位点。