Olfactory aversive conditioning alters olfactory bulb mitral/tufted cell glomerular odor responses.
Olfactory aversive conditioning alters olfactory bulb mitral/tufted cell glomerular odor responses.
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DOI：
10.3389/fnsys.2012.00016
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发表时间：
2012
影响因子：
3
通讯作者：
Fletcher ML
中科院分区：
文献类型：
--
作者：
Fletcher ML
嗅球（OB）的受体神经元输入的解剖组织允许气味信息被转换成气味特异性的空间地图的二尖瓣/簇状（M/T）细胞肾小球活动在OB的上水平。在其他感觉系统中，刺激的神经元表征可以在学习后重组或增强。虽然哺乳动物的OB已被证明经历经验依赖性的可塑性在肾小球水平，它仍然不清楚，如果类似的代表性变化发生在（M/T）细胞肾小球气味表示学习后。为了解决这个问题，在OB（M/T）细胞中表达基于GFP的钙指示剂（GCaMP 2）的小鼠中对气味诱发的肾小球活动模式进行成像。肾小球气味反应成像之前和之后的嗅觉联想条件反射，以避免脚休克。条件反射后，我们没有发现肾小球代表性的整体重组。然而，训练确实显著改变了小鼠中代表性的单个肾小球的振幅，其中气味与足部电击一起呈现。此外，特定配对的脚休克与气味介绍导致增加的反应，主要是在最初的弱激活肾小球。总体而言，这些结果表明，联想条件反射可以通过增强某些肾小球对习得气味的反应来增强OB内气味的初始表现。
The anatomical organization of receptor neuron input into the olfactory bulb (OB) allows odor information to be transformed into an odorant-specific spatial map of mitral/tufted (M/T) cell glomerular activity at the upper level of the OB. In other sensory systems, neuronal representations of stimuli can be reorganized or enhanced following learning. While the mammalian OB has been shown to undergo experience-dependent plasticity at the glomerular level, it is still unclear if similar representational change occurs within (M/T) cell glomerular odor representations following learning. To address this, odorant-evoked glomerular activity patterns were imaged in mice expressing a GFP-based calcium indicator (GCaMP2) in OB (M/T) cells. Glomerular odor responses were imaged before and after olfactory associative conditioning to aversive foot shock. Following conditioning, we found no overall reorganization of the glomerular representation. Training, however, did significantly alter the amplitudes of individual glomeruli within the representation in mice in which the odor was presented together with foot shock. Further, the specific pairing of foot shock with odor presentations lead to increased responses primarily in initially weakly activated glomeruli. Overall, these results suggest that associative conditioning can enhance the initial representation of odors within the OB by enhancing responses to the learned odor in some glomeruli.