生物谷报道:有关长时程学习和记忆的研究一直是人们关心的问题,长时程记忆到底是什么机理?是信号还是基因/蛋白质?在今天刚刚出版的Nature上报道在果蝇上研究表明,cathepsin是果蝇长时程记忆的一种重要蛋白。在果蝇中称Crammer蛋白,如果过表达这种蛋白,它的长时程记忆能力明显增强,而这个基因缺陷的果蝇则失去长时程记忆能力。
Nature 430, 460 - 463 (22 July 2004); doi:10.1038/nature02726
Drosophila long-term memory formation involves regulation of cathepsin activity
DANIEL COMAS*, FLORIAN PETIT* & THOMAS PREAT
Développement, Évolution et Plasticité du Système Nerveux, CNRS, 1, Avenue de la Terrasse, 91190 Gif sur Yvette, France
* These authors contributed equally to this work.
Correspondence and requests for materials should be addressed to T.P. (preat@iaf.cnrs-gif.fr).
Whereas short-term memory lasts from minutes to hours, long-term memory (LTM) can last for days or even an entire lifetime. LTM generally forms after spaced repeated training sessions and involves the regulation of gene expression1, 2, thereby implicating transcription factors in the initial steps of LTM establishment3. However, the direct participation of effector genes in memory formation has been rarely documented, and many of the mechanisms involved in LTM formation remain to be understood. Here we describe a Drosophila melanogaster mutant, crammer (cer), which shows a specific LTM defect. The cer gene encodes an inhibitor of a subfamily of cysteine proteinases, named cathepsins, some of which might be involved in human Alzheimer's disease4. The Cer peptide was found in the mushroom bodies (MBs), the Drosophila olfactory memory centre and in glial cells around the MBs. The overexpression of cer in glial cells but not in MB neurons induces a decrease in LTM, suggesting that Cer might have a role in glia and that the concentration of the Cer peptide is critical for LTM. In wild-type flies, cer expression transiently decreases after LTM conditioning, indicating that cysteine proteinases are activated early in LTM formation.
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