Sato Nobuya, Sakata Hideo, Tanaka Yuji L, Taira Masato
Division of Applied System Neuroscience, Advanced Medical Research Center, Nihon University Graduate School of Medical Science, Ohyaguchi-Kamicho 30-1, Itabashi, Tokyo 173-8610, Japan.
Proc Natl Acad Sci U S A. 2006 Nov 7;103(45):17001-6. doi: 10.1073/pnas.0604277103. Epub 2006 Oct 26.
To examine the neural basis of route knowledge by which one can reach one's destination, we recorded the activity of 580 neurons in the monkey medial parietal region (MPR) while monkeys actively navigated through a virtual environment. One hundred eighty of these neurons (31%) showed significant responses to the monkeys' movements in the virtual environment. Of these responsive neurons, 77% (139/180) showed responses associated with a specific movement at a specific location (navigation neurons), 8% (14/180) showed responses associated with a specific movement (movement-selective neurons), and the remaining 27 neurons (15%) were nonselective. We found navigation neurons whose responses to the same movement at the same location were modulated depending on the route that the monkey was currently taking, that is, in a route-selective manner (32 of 59 tested neurons among 139 navigation neurons, route-selective navigation neurons). The reversible inactivation of MPR neurons by muscimol resulted in a monkey becoming lost during the navigation task trial. These results suggest that MPR plays a critical role in route-based navigation by integrating location information and self-movement information.
为了研究人们能够到达目的地所依赖的路线知识的神经基础，我们在猴子积极地在虚拟环境中导航时，记录了猴子内侧顶叶区域（MPR）中580个神经元的活动。其中180个神经元（31%）对猴子在虚拟环境中的运动表现出显著反应。在这些有反应的神经元中，77%（139/180）表现出与特定位置的特定运动相关的反应（导航神经元），8%（14/180）表现出与特定运动相关的反应（运动选择神经元），其余27个神经元（15%）无选择性。我们发现，对于同一位置的相同运动，其反应会根据猴子当前所走的路线而受到调制的导航神经元，即具有路线选择性的导航神经元（在139个导航神经元中的59个测试神经元中有32个，为路线选择性导航神经元）。用蝇蕈醇对MPR神经元进行可逆性失活会导致猴子在导航任务试验中迷路。这些结果表明，MPR通过整合位置信息和自身运动信息，在基于路线的导航中发挥着关键作用。
