2009-02-26

[文摘] 學習經驗也能遺傳給下一代

SkyOrggLee 報導

記憶和經驗有沒有辦法遺傳給下一代呢? 現在研究人員發現胎兒在母體懷孕期間,也有可能繼承母親了的學習經驗。

位於美國士波士頓的塔夫茨大學,Feig等人的研究發現,將青春期前的ras-grf knock out的母鼠,放置在複雜的環境(enriched environment, EE)下學習,可以增加神經細胞的生理過程(long term potentiation, LTP),而初生的幼鼠完全沒有經驗複雜的學習環境,相較於一般的幼鼠卻發現到LTP的增加。

這種特徵遺傳的想法最早是在19世紀拉馬克(Larmarck)提出,然而並未獲得重視,有別於現今遺傳學多採訥孟德爾遺傳學的理論,以DNA為遺傳物質做為媒介,遺傳給後代。

如果相似的現象也發生在人的身上,母親幼年的學習經驗將有可能留傳給下一代。

原始論文摘要:

Transgenerational Rescue of a Genetic Defect in Long-Term Potentiation and Memory Formation by Juvenile Enrichment

Junko A. Arai,1 * Shaomin Li,1 * Dean M. Hartley,2 and Larry A. Feig1

1Sackler School of Biomedical Sciences and Departments of Biochemistry and Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111, and 2Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois 60612

Correspondence should be addressed to Larry A. Feig at the above address. Email: larry.feig@tufts.edu

The idea that qualities acquired from experience can be transmitted to future offspring has long been considered incompatible with current understanding of genetics. However, the recent documentation of non-Mendelian transgenerational inheritance makes such a "Lamarckian"-like phenomenon more plausible. Here, we demonstrate that exposure of 15-d-old mice to 2 weeks of an enriched environment (EE), that includes exposure to novel objects, elevated social interactions and voluntary exercise, enhances long-term potentiation (LTP) not only in these enriched mice but also in their future offspring through early adolescence, even if the offspring never experience EE. In both generations, LTP induction is augmented by a newly appearing cAMP/p38 MAP kinase-dependent signaling cascade. Strikingly, defective LTP and contextual fear conditioning memory normally associated with ras-grf knock-out mice are both masked in the offspring of enriched mutant parents. The transgenerational transmission of this effect occurs from the enriched mother to her offspring during embryogenesis. If a similar phenomenon occurs in humans, the effectiveness of one's memory during adolescence, particularly in those with defective cell signaling mechanisms that control memory, can be influenced by environmental stimulation experienced by one's mother during her youth.

Key words: synaptic plasticity; LTP; kinase; environmental; fear; memory formation


Received Oct. 17, 2008; revised Dec. 14, 2008; accepted Dec. 16, 2008.

Correspondence should be addressed to Larry A. Feig at the above address. Email: larry.feig@tufts.edu

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