Sustained activation of hippocampal pyramidal cells by 'space clamping' in a running wheel
Sustained activation of hippocampal pyramidal cells by 'space clamping' in a running wheel
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DOI：
10.1046/j.1460-9568.1999.00446.x
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发表时间：
1999-01-01
影响因子：
3.4
通讯作者：
Buzsáki, G
中科院分区：
文献类型：
--
作者：
Czurkó, A;Hirase, H;Buzsáki, G
与大脑的感觉皮层区域相比，海马体的相关生理输入导致锥体细胞的选择性激活，在很大程度上是未知的。锥体细胞被认为是通过空间线索以及各种感觉和运动刺激而被阶段性激活的。在这里，我们使用了一种行为“空间钳”方法，该方法将积极奔跑的动物限制在空间中的一个定义位置（跑轮）并保持感官输入恒定。当大鼠在车轮上奔跑时，记录到的 CA1 锥体细胞中有 12% 选择性活跃。细胞放电特定于运行方向，并在旋转记录装置后消失。只要大鼠在轮子上持续奔跑，锥体细胞和中间神经元的放电频率就会持续。此外，尽管海马θ波的频率保持恒定，但锥体细胞和中间神经元的放电频率随着跑步速度的增加而增加。一些“与轮相关”的锥体细胞的放电频率可以在 10 至 100 cm/s 之间增加 10 倍以上，而“非轮”细胞的放电频率始终保持较低水平。我们假设：（i）海马锥体细胞局部放电的必要条件是θ振荡的存在； (ii) 只要存在 theta 活性，相关刺激就可以有选择性地激活海马锥体细胞。
In contrast to sensory cortical areas of the brain, the relevant physiological inputs to the hippocampus, leading to selective activation of pyramidal cells, are largely unknown. Pyramidal cells are thought to be phasically activated by spatial cues and a variety of sensory and motor stimuli. Here, we used a behavioural 'space clamp' method, which involved the confinement of the actively running animal in a defined position in space (running wheel) and kept sensory inputs constant. Twelve percent of the recorded CA1 pyramidal cells were selectively active while the rat was running in the wheel. Cell firing was specific to the direction of running and disappeared after rotating the recording apparatus. The discharge frequency of pyramidal cells and interneurons was sustained as long as the rat ran continuously in the wheel. Furthermore, the discharge frequency of pyramidal cells and interneurons increased with increasing running velocity, even though the frequency of hippocampal theta waves remained constant. The discharge frequency of some 'wheel-related' pyramidal cells could increase more than 10-fold between 10 and 100 cm/s, whereas the firing rate of 'non-wheel' cells remained constantly low. We hypothesize that: (i) a necessary condition for place-specific discharge of hippocampal pyramidal cells is the presence of theta oscillation; and (ii) relevant stimuli can tonically and selectively activate hippocampal pyramidal cells as long as theta activity is present.