Kyd Rachel J, Bilkey David K
Department of Psychology and the Neuroscience Research Centre, University of Otago, Dunedin, New Zealand.
Cereb Cortex. 2003 May;13(5):444-51. doi: 10.1093/cercor/13.5.444.
It has previously been proposed that the prefrontal cortex has a role in 'executive processes' and memory function. These activities presumably require modulation of activity in posterior cortex. On the basis of this hypothesis, it was proposed that prefrontal cortex lesions might alter neural activity in the hippocampus, a region implicated in memory processing. A major feature of hippocampal activity is place-related firing. Single unit recordings of CA1 complex spike cells ('place cells'; n = 64) were made as rats with prefrontal lesions (n = 6) or sham surgeries (n = 7) foraged freely. The spatial information content provided by spikes in cells of lesion animals was significantly greater than in sham-group animals, although the size of their place fields was not affected. The location of the firing fields of lesion-group rats were less stable across time when either 5 h or 3 min intervals were inserted between successive recordings of the same cell. It was hypothesized that animals with prefrontal lesions may be overly influenced by local, less stable environmental cues than sham rats. This may explain both the spatial information content and stability findings. These findings indicate that prefrontal cortex normally modulates spatial responses in the hippocampus.
此前有人提出，前额叶皮层在“执行过程”和记忆功能中发挥作用。这些活动可能需要调节后皮层的活动。基于这一假设，有人提出前额叶皮层损伤可能会改变海马体中的神经活动，海马体是一个与记忆处理有关的区域。海马体活动的一个主要特征是与位置相关的放电。在有前额叶损伤的大鼠（n = 6）或假手术大鼠（n = 7）自由觅食时，对CA1复合棘波细胞（“位置细胞”；n = 64）进行单单位记录。损伤动物细胞中尖峰提供的空间信息内容明显大于假手术组动物，尽管它们位置野的大小没有受到影响。当在同一细胞的连续记录之间插入5小时或3分钟的间隔时，损伤组大鼠放电野的位置随时间的稳定性较差。据推测，与假手术大鼠相比，前额叶损伤的动物可能更容易受到局部、不太稳定的环境线索的影响。这可能解释了空间信息内容和稳定性的研究结果。这些发现表明，前额叶皮层通常会调节海马体中的空间反应。
