GABAergic phenotype of periglomerular cells in the rodent olfactory bulb
GABAergic phenotype of periglomerular cells in the rodent olfactory bulb
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DOI：
10.1002/cne.21356
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发表时间：
2007-06-20
影响因子：
2.5
通讯作者：
Sassoe-Pognetto, M.
中科院分区：
文献类型：
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作者：
Panzanelli, P.;Fritschy, J. M.;Sassoe-Pognetto, M.
在啮齿类动物嗅球中的肾小球周围细胞在解剖学和神经化学上是异质的。在这里，我们研究了主要类型的PG细胞是否使用γ -氨基丁酸（GABA）作为神经递质。除了表达酪氨酸羟化酶（TH）、钙结合蛋白D-28k （CB）和calretinin （CR）的三种已知PG细胞亚型外，我们还发现了一种含有GABA(a)受体α 5亚基的新型PG细胞群。与之前在大鼠中的研究一致，我们发现th阳性细胞也被标记有针对GABA的抗体，而表达CB或α 5亚基的PG细胞则是GABA阴性。使用GAD67-GFP敲入小鼠，我们发现所有PG细胞亚型都表达GAD67-GFP。Calretinin标记绿色荧光蛋白（GFP）阳性细胞的主要部分（44%），其次是TH (16%)， CB（14%）和α 5亚基（13%）。这些神经元群之间没有重叠，约占gad67 - gfp阳性细胞的85%。然后，我们证明了标记TH、CB或CR的PG细胞建立了表达谷氨酸脱羧酶（GAD）或囊泡抑制性氨基酸转运蛋白（VGAT）的树突突触，而与它们对GABA的免疫反应性无关。此外，CB-、CR-和th阳性树突与含有α 1或α 3亚基（在二尖瓣细胞和簇状细胞中发现）和α 2亚基（在PG细胞中表达）的GABA(A)受体簇相对应。总之，这些发现表明PG细胞的所有主要亚型都是gaba能细胞。此外，他们表明PG细胞向主要神经元的树突提供gabaergy输入，并与其他gabaergy中间神经元相互连接，这些中间神经元很可能是其他PG细胞。
Periglomerular (PG) cells in the rodent olfactory bulb are heterogeneous anatomically and neurochemically. Here we investigated whether major classes of PG cells use gamma-aminobutyric acid (GABA) as a neurotransmitter. In addition to three known subtypes of PG cells expressing tyrosine hydroxylase (TH), calbindin D-28k (CB), and calretinin (CR), we identified a novel PG cell population containing the GABA(A) receptor alpha 5 subunit. Consistent with previous studies in the rat, we found that TH-positive cells were also labeled with antibodies against GABA, whereas PG cells expressing CB or the alpha 5 subunit were GABA-negative. Using GAD67-GFP knockin mice, we found that all PG cell subtypes expressed GAD67-GFP. Calretinin labeled the major fraction (44%) of green fluorescent protein (GFP)-positive cells, followed by TH (16%), CB (14%), and the alpha 5 subunit (13%). There was no overlap between these neuronal populations, which accounted for approximate to 85% of GAD67-GFP-positive cells. We then demonstrated that PG cells labeled for TH, CB, or CR established dendrodendritic synapses expressing glutamic acid decarboxylase (GAD) or the vesicular inhibitory amino acid transporter, VGAT, irrespective of their immunoreactivity for GABA. In addition, CB-, CR-, and TH-positive dendrites were apposed to GABA(A) receptor clusters containing the alpha 1 or alpha 3 subunits, which are found in mitral and tufted cells, and the alpha 2 subunit, which is expressed by PG cells. Together, these findings indicate that all major subtypes of PG cells are GABAergic. In addition, they show that PG cells provide GABAergic input to the dendrites of principal neurons and are interconnected with other GABAergic interneurons, which most likely are other PG cells.