Institute of Behavioural Neuroscience, Department of Cognitive, Perceptual and Brain Sciences, Division of Psychology and Language Sciences, University College London, London, UK.
Nat Neurosci. 2011 Aug 7;14(9):1182-8. doi: 10.1038/nn.2892.
The subjective sense of space may result in part from the combined activity of place cells in the hippocampus and grid cells in posterior cortical regions such as the entorhinal cortex and pre- and parasubiculum. In horizontal planar environments, place cells provide focal positional information, whereas grid cells supply odometric (distance measuring) information. How these cells operate in three dimensions is unknown, even though the real world is three-dimensional. We investigated this issue in rats exploring two different kinds of apparatus: a climbing wall (the 'pegboard') and a helix. Place and grid cell firing fields had normal horizontal characteristics but were elongated vertically, with grid fields forming stripes. It seems that grid cell odometry (and by implication path integration) is impaired or absent in the vertical domain, at least when the rat itself remains horizontal. These findings suggest that the mammalian encoding of three-dimensional space is anisotropic.
空间的主观感觉可能部分源于海马体中的位置细胞和后皮质区域（如内嗅皮层和前、副海马区）中的网格细胞的联合活动。在水平平面环境中，位置细胞提供焦点位置信息，而网格细胞提供里程计（距离测量）信息。尽管现实世界是三维的，但这些细胞在三维空间中的运作方式尚不清楚。我们在探索两种不同设备的大鼠中研究了这个问题：攀爬壁（“钉板”）和螺旋。位置和网格细胞的发射场具有正常的水平特征，但垂直方向拉长，网格场形成条纹。似乎网格细胞的里程计（以及隐含的路径积分）在垂直方向上受到损害或缺失，至少当大鼠本身保持水平时是这样。这些发现表明，哺乳动物对三维空间的编码是各向异性的。
