ODOR-INDUCED INCREASES IN C-FOS MESSENGER-RNA EXPRESSION REVEAL AN ANATOMICAL UNIT FOR ODOR PROCESSING IN OLFACTORY-BULB
ODOR-INDUCED INCREASES IN C-FOS MESSENGER-RNA EXPRESSION REVEAL AN ANATOMICAL UNIT FOR ODOR PROCESSING IN OLFACTORY-BULB
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DOI：
10.1073/pnas.90.8.3329
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发表时间：
1993-04-15
影响因子：
11.1
通讯作者：
GALL, C
中科院分区：
文献类型：
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作者：
GUTHRIE, KM;ANDERSON, AJ;GALL, C
立即早期基因 c-fos 的表达用于评估警觉大鼠短暂暴露于特定气味时嗅球神经元的协调激活。将 c-fos mRNA 原位杂交与相邻切片分析中 2-脱氧-D-[C-14]葡萄糖掺入的区域增加进行比较。最近从笼子中移出的大鼠嗅球中的 c-fos mRNA 水平较高，但在相对无味的室内放置 30 分钟的大鼠中，嗅球中的 c-fos mRNA 水平较低。向老鼠发出特定气味提醒仅需 5 分钟，跨越主嗅球层的放射状分布的神经元群中的 c-fos mRNA 就会增加。互补 RNA (cRNA) 标记的神经元集合由肾小球层中的细胞组成，精确定义了单个肾小球和下面的簇状细胞、二尖瓣细胞和颗粒细胞的边界。颗粒细胞层中的激活区域比覆盖的肾小球层中的激活区域宽得多，因此表现出烧瓶状轮廓，而不是柱状轮廓。 cRNA 标记细胞阵列的延髓分布因气味不同而不同，并且在肾小球层中对应于高 2-脱氧-D-[C-14]葡萄糖摄取的焦点区域。非竞争性 N-甲基-D-天冬氨酸受体拮抗剂 MK801 的施用并没有减弱 c-fos 的气味诱导，而是增加了整个球茎的 c-fos mRNA 水平。我们认为，通过气味刺激表达增加的 c-fos mRNA 的神经元集合代表了行为大鼠主嗅球中感觉处理的主要功能单位。
Expression of the immediate-early gene c-fos was used to evaluate the coordinate activation of olfactory bulb neurons by brief exposure to specific odors in the alert rat. In situ hybridization to c-fos mRNA was compared to regional increases in 2-deoxy-D-[C-14]glucose incorporation in an adjacent section analysis. Levels of c-fos mRNA in olfactory bulb were high in rats recently removed from their home cage but were low in animals placed in a relatively odor-free chamber for 30 min. Presentation of specific odors to alert rats for as little as 5 min increased c-fos mRNA in radially distributed neuronal ensembles that spanned the lamina of the main olfactory bulb. The complementary RNA (cRNA)-labeled neuronal collectives consisted of cells in the glomerular layer that precisely defined the borders of individual glomeruli and underlying tufted, mitral, and granule cells. The activated fields were much broader in the granule cell layer than in the overlying glomerular layer and thus exhibited a flask-like, as opposed to a columnar, contour. The bulbar distribution of cRNA-labeled cell arrays differed with different odors and, in the glomerular layer, corresponded to focal regions of high 2-deoxy-D-[C-14]glucose uptake. Administration of the noncompetitive N-methyl-D-aspartate receptor antagonist MK801 did not attenuate the odor induction of c-fos but, instead, increased c-fos mRNA levels throughout the bulb. We propose that the neuronal ensembles expressing increased c-fos mRNA with odor stimulation represent principal functional units of sensory processing in the main olfactory bulb of the behaving rat.