Yoshida Motoharu, Hasselmo Michael E
Center for Memory and Brain, Boston University, Boston, Massachusetts 02215, USA.
J Neurosci. 2009 Apr 15;29(15):4945-52. doi: 10.1523/JNEUROSCI.5154-08.2009.
The rat postsubiculum has head direction cells that fire persistently when the rat's head is oriented in particular directions. This persistent firing is maintained even if the rat is motionless, when spatial cues are removed from the environment and in the dark, but the mechanism that supports persistent firing of the head direction cells is still unclear. Here, using in vitro whole-cell patch recording, we found that a short-triggering stimulus (as few as five induced spikes) can initiate persistent firing in cells of the postsubiculum. Pharmacological results indicated that this persistent firing is driven by a calcium-sensitive nonselective cation current. The distribution of cells with persistent firing in superficial and deep layers in the postsubiculum was similar to that of head direction cells. These results suggest that persistent firing of head direction cells in the postsubiculum could be supported by an intrinsic mechanism.
大鼠的后下托有头部方向细胞，当大鼠头部朝向特定方向时，这些细胞会持续放电。即使大鼠静止不动、从环境中移除空间线索以及处于黑暗中时，这种持续放电仍会维持，但支持头部方向细胞持续放电的机制仍不清楚。在这里，我们使用体外全细胞膜片钳记录发现，一个短触发刺激（少至五个诱发动作电位）就能引发后下托细胞的持续放电。药理学结果表明，这种持续放电是由一种钙敏感的非选择性阳离子电流驱动的。后下托浅层和深层中具有持续放电能力的细胞分布与头部方向细胞的分布相似。这些结果表明，后下托中头部方向细胞的持续放电可能由一种内在机制支持。
