九乡新闻网香港到台湾船票:J neurosci.：深度刺激可促进小鼠脑细胞再生
来源：百度文库 编辑：九乡新闻网 时间：2024/04/29 03:58:43
据美国物理学家组织网9月20日报道，加拿大儿童医院的研究人员通过动物实验发现，用一种名为深度脑刺激的临床干预疗法向大脑特定区域施加电脉冲，能使脑细胞再生，有望帮助提高认知能力并增强记忆。该研究发表在9月21日的《神经科学期刊》上。
“深度脑刺激在治疗运动紊乱方面非常有效，比如帕金森氏症。”论文作者之一、加拿大儿童医院博士鲍尔·弗兰克兰说，“最近，我们进一步探索了这种疗法在广泛的神经病和精神病学治疗领域的用途，这些新发现在治疗人类记忆紊乱方面有着重要的临床价值。”
在新研究中，弗兰克兰和同事发现，用电脉冲刺激内嗅区皮质（与海马回直接联系的区域）一个小时，成年小鼠海马回的新生细胞增加了两倍。大脑海马回是学习和记忆中心，在整个生命期间，这里都有新的细胞出生。尽管新细胞的爆发式增长只持续了一个星期，但在此期间，细胞产生了正常的开放窗口，与附近的脑细胞建立起联系。
6个星期之后，研究人员设计了一项实验来评价新连接在一起的细胞是否引起了记忆方面的变化。他们在一个小水池中放了一块浸没在水下的模拟陆地，测试小鼠学习辨别方向登陆的能力，并把它们和没有受过电流刺激的小鼠比较。结果发现，经过深度脑刺激治疗的小鼠有更多时间游到陆地附近，这表明刺激内嗅区皮质提高了它们的空间学习能力。
弗兰克兰解释说：“深度脑刺激对认知的改善效果，可能是由于新的神经元的形成。”
对此，美国罗莎琳德·富兰克林医科大学博士、肝细胞与脑修复专家丹尼尔·彼得森说：“迄今为止，深度脑刺激临床效果的神经生物学基础还不明确。这项研究认为，刺激特定的脑线路可能导致在特定脑区发展出新的功能细胞。”
在另一项相关研究中，加拿大多伦多西部医院的安德烈斯·洛扎诺领导的小组最近也公布了他们的第一阶段临床试验，表明对穹隆区（也和海马回直接联系）进行深度刺激会延缓痴呆或患有其他认知障碍病人的认知力下降。（生物谷 Bioon.com）
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.