據(jù)美國物理學(xué)家組織網(wǎng)9月20日報道，加拿大兒童醫(yī)院的研究人員通過動物實(shí)驗發(fā)現(xiàn),，用一種名為深度腦刺激的臨床干預(yù)療法向大腦特定區(qū)域施加電脈沖,，能使腦細(xì)胞再生,，有望幫助提高認(rèn)知能力并增強(qiáng)記憶。該研究發(fā)表在9月21日的《神經(jīng)科學(xué)期刊》上,。
“深度腦刺激在治療運(yùn)動紊亂方面非常有效,，比如帕金森氏癥。”論文作者之一,、加拿大兒童醫(yī)院博士鮑爾·弗蘭克蘭說,，“最近，我們進(jìn)一步探索了這種療法在廣泛的神經(jīng)病和精神病學(xué)治療領(lǐng)域的用途,，這些新發(fā)現(xiàn)在治療人類記憶紊亂方面有著重要的臨床價值,。”
在新研究中，弗蘭克蘭和同事發(fā)現(xiàn),，用電脈沖刺激內(nèi)嗅區(qū)皮質(zhì)（與海馬回直接聯(lián)系的區(qū)域）一個小時,，成年小鼠海馬回的新生細(xì)胞增加了兩倍。大腦海馬回是學(xué)習(xí)和記憶中心,，在整個生命期間,，這里都有新的細(xì)胞出生。盡管新細(xì)胞的爆發(fā)式增長只持續(xù)了一個星期,，但在此期間,，細(xì)胞產(chǎn)生了正常的開放窗口，與附近的腦細(xì)胞建立起聯(lián)系,。
6個星期之后,，研究人員設(shè)計了一項實(shí)驗來評價新連接在一起的細(xì)胞是否引起了記憶方面的變化。他們在一個小水池中放了一塊浸沒在水下的模擬陸地,，測試小鼠學(xué)習(xí)辨別方向登陸的能力,，并把它們和沒有受過電流刺激的小鼠比較。結(jié)果發(fā)現(xiàn),，經(jīng)過深度腦刺激治療的小鼠有更多時間游到陸地附近,，這表明刺激內(nèi)嗅區(qū)皮質(zhì)提高了它們的空間學(xué)習(xí)能力。
弗蘭克蘭解釋說：“深度腦刺激對認(rèn)知的改善效果,，可能是由于新的神經(jīng)元的形成,。”
對此，美國羅莎琳德·富蘭克林醫(yī)科大學(xué)博士,、肝細(xì)胞與腦修復(fù)專家丹尼爾·彼得森說：“迄今為止,，深度腦刺激臨床效果的神經(jīng)生物學(xué)基礎(chǔ)還不明確,。這項研究認(rèn)為，刺激特定的腦線路可能導(dǎo)致在特定腦區(qū)發(fā)展出新的功能細(xì)胞,。”
在另一項相關(guān)研究中,，加拿大多倫多西部醫(yī)院的安德烈斯·洛扎諾領(lǐng)導(dǎo)的小組最近也公布了他們的第一階段臨床試驗，表明對穹隆區(qū)（也和海馬回直接聯(lián)系）進(jìn)行深度刺激會延緩癡呆或患有其他認(rèn)知障礙病人的認(rèn)知力下降,。（生物谷 Bioon.com）
doi: 10.1523/?JNEUROSCI.3100-11.2011
PMC:
PMID:
Stimulation of Entorhinal Cortex Promotes Adult Neurogenesis and Facilitates Spatial Memory
Scellig S. D. Stone, Cátia M. Teixeira, Loren M. DeVito, Kirill Zaslavsky, Sheena A. Josselyn, Andres M. Lozano, and Paul W. Frankland
Deep brain stimulation (DBS) is an established therapeutic modality for the treatment of movement disorders and an emerging therapeutic approach for the treatment of disorders of mood and thought. For example, recently we have shown that DBS of the fornix may ameliorate cognitive decline associated with dementia. However, like other applications of DBS, the mechanisms mediating these clinical effects are unknown. As DBS modulates neurophysiological activity in targeted brain regions, DBS might influence cognitive function via activity-dependent regulation of hippocampal neurogenesis. Using stimulation parameters analogous to clinical high-frequency DBS, here we addressed this question in mice. We found that acute stimulation of the entorhinal cortex (EC) transiently promoted proliferation in the dentate gyrus (DG). Cells generated as a consequence of stimulation differentiated into neurons, survived for at least several weeks, and acquired normal dentate granule cell (DGC) morphology. Importantly, stimulation-induced promotion of neurogenesis was limited to the DG and not associated with changes in apoptotic cell death. Using immunohistochemical approaches, we found that, once sufficiently mature, these stimulation-induced neurons integrated into hippocampal circuits supporting water-maze memory. Finally, formation of water-maze memory was facilitated 6 weeks (but not 1 week) after bilateral stimulation of the EC. The delay-dependent nature of these effects matches the maturation-dependent integration of adult-generated DGCs into dentate circuits supporting water-maze memory. Furthermore, because the beneficial effects of EC stimulation were prevented by blocking neurogenesis, this suggests a causal relationship between stimulation-induced promotion of adult neurogenesis and enhanced spatial memory.
