Park Jin-Sung, Onodera Takashi, Nishimura Shin-ichi, Thompson Richard F, Itohara Shigeyoshi
Laboratories for Behavioral Genetics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
Proc Natl Acad Sci U S A. 2006 Apr 4;103(14):5549-54. doi: 10.1073/pnas.0601150103. Epub 2006 Mar 28.
The anterior interpositus nucleus (AIN) is the proposed site of memory formation of eyeblink conditioning. A large part of the underlying molecular events, however, remain unknown. To elucidate the molecular mechanisms, we examined transcriptional changes in the AIN of mice trained with delay eyeblink conditioning using microarray, quantitative real-time RT-PCR, and in situ hybridization techniques. Microarray analyses suggested that transcriptionally up-regulated gene sets were largely different between early (3-d training) and late (7-d) stages. Quantitative real-time RT-PCR aided by laser microdissection indicated that the expression of representative EARLY genes (Sgk, IkBa, and Plekhf1) peaked at 1-d training in both the paired and unpaired conditioning groups, and was maintained at a higher level in the paired group than in the unpaired group after 3-d training. In situ hybridization revealed increased expression of these genes in broad cerebellar areas, including the AIN, with no hemispheric preferences. In contrast, the expression of representative LATE genes (Vamp1, Camk2d, and Prkcd) was selectively increased in the AIN of the 7-d paired group, with dominance in the ipsilateral AIN. Increased Vamp1 mRNA expression was restricted to the ipsilateral dorsolateral hump, a subregion of the AIN. These expression patterns of two distinct subsets of genes fit well with the two-stage learning theory, which proposes emotional and motor learning phases, and support the notion that AIN has a crucial role in memory formation of eyeblink conditioning.
前间位核（AIN）被认为是眨眼条件反射记忆形成的部位。然而，其潜在的分子事件大部分仍不清楚。为了阐明分子机制，我们使用微阵列、定量实时逆转录聚合酶链反应和原位杂交技术，研究了经延迟眨眼条件反射训练的小鼠AIN中的转录变化。微阵列分析表明，早期（3天训练）和晚期（7天）阶段转录上调的基因集有很大差异。激光显微切割辅助的定量实时逆转录聚合酶链反应表明，代表性早期基因（Sgk、IkBa和Plekhf1）在配对和非配对条件反射组的1天训练时表达均达到峰值，3天训练后，配对组中这些基因的表达维持在比非配对组更高的水平。原位杂交显示，这些基因在包括AIN在内的广泛小脑区域表达增加，无半球偏好。相比之下，代表性晚期基因（Vamp1、Camk2d和Prkcd）的表达在7天配对组的AIN中选择性增加，在同侧AIN中占优势。Vamp1 mRNA表达增加仅限于AIN的一个亚区域——同侧背外侧隆起。这两个不同基因子集的表达模式与提出情感和运动学习阶段的两阶段学习理论非常吻合，并支持AIN在眨眼条件反射记忆形成中起关键作用的观点。
