Russell Noah A, Horii Arata, Smith Paul F, Darlington Cynthia L, Bilkey David K
Department of Psychology and Neuroscience Research Centre, School of Medical Sciences, University of Otago, Dunedin, 9001 New Zealand.
J Neurosci. 2003 Jul 23;23(16):6490-8. doi: 10.1523/JNEUROSCI.23-16-06490.2003.
The hippocampus is thought to be important for spatial representation processes that depend on the integration of both self-movement and allocentric cues. The vestibular system is a particularly important source of self-movement information that may contribute to this spatial representation. To test the hypothesis that the vestibular system provides self-movement information to the hippocampus, rats were given either a bilateral labyrinthectomy (n = 6) or a sham surgery (n = 6), and at least 60 d after surgery hippocampal CA1 neurons were recorded extracellularly while the animals foraged freely in an open arena. Recorded cells were classified as complex spiking (n = 80) or noncomplex spiking (n = 33) neurons, and their spatial firing fields (place fields) were examined. The most striking effect of the lesion was that it appeared to completely abolish location-related firing. The results of this and previous studies provide converging evidence demonstrating that vestibular information is processed by the hippocampus. The disruption of the vestibular input to the hippocampus may interfere with the reconciliation of internal self-movement signals with the changes to the external sensory inputs that occur as a result of that movement. This would disrupt the ability of the animal to integrate allocentric and egocentric information into a coherent representation of space.
海马体被认为对于依赖自身运动和空间线索整合的空间表征过程很重要。前庭系统是自身运动信息的一个特别重要的来源，可能有助于这种空间表征。为了检验前庭系统向海马体提供自身运动信息的假设，给大鼠进行双侧迷路切除术（n = 6）或假手术（n = 6），并且在手术后至少60天，当动物在开放场地自由觅食时，对海马体CA1神经元进行细胞外记录。将记录的细胞分类为复合放电（n = 80）或非复合放电（n = 33）神经元，并检查它们的空间放电场（位置场）。损伤最显著的影响是它似乎完全消除了与位置相关的放电。这项研究和先前研究的结果提供了一致的证据，证明前庭信息由海马体处理。前庭输入到海马体的中断可能会干扰内部自身运动信号与因该运动而发生的外部感觉输入变化的协调。这将破坏动物将空间线索和自我中心信息整合为连贯空间表征的能力。
