The function of cerebellar nucleus and cortex in eyeblink conditioning

条件性眨眼是典型的小脑依赖运动学习。小脑皮质和间位核分别通过苔藓纤维和攀缘纤维投射接受条件刺激(CS)和非条件刺激(US)信息。然而，联合眨眼学习的潜在机制仍不清楚。为了分析IN中参与条件性反应(CR)获得的神经可塑性，我在体内记录了眨眼条件反射过程中的神经活动。没有训练过眨眼条件作用的小鼠的IN中的一些神经元显示出活动增加，只对US有反应。另一方面，训练小鼠的IN神经元表现出对US和CS的反应增加的活动。为了分析CR的详细时间信息，我们使用高速摄像机观察了眼睑的运动。接受过眨眼训练的小鼠对CS有更大的眼皮闭合反应。小脑皮质损毁对小、短潜伏期反应有CR反应。

Conditioned eyeblink is typical cerebellum-dependent motor learning. The cerebellar cortex and the interpositus nucleus (IN) receive both conditioned stimulus (CS) and unconditioned stimulus (US) information through the mossy fiber and climbing fiber projections, respectively. However, the underlying mechanism of associative eyeblink learning remains unclear.To analyze neural plasticity in the IN involved in acquisition of conditioned response (CR), I recorded neural activity during eyeblink conditioning in vivo. Some neurons in the IN of mice which have not trained eyeblink conditioning showed increased activities respond only to US. On the other hand, IN neurons of trained mice showed increased activities respond to both US and CS.To analyze the detail temporal information of CR, we observed the eyelid movement using high-speed video camera. Mice which have trained eyeblink conditioning showed larger eyelid closure respond to CS. Lesion of cerebellar cortex made CR to small and short latency response.