Chronic changes in inputs to dorsal Y neurons accompany VOR motor learning
Chronic changes in inputs to dorsal Y neurons accompany VOR motor learning
复制标题
DOI：
10.1152/jn.01061.2005
复制
发表时间：
2006-03-01
影响因子：
2.5
通讯作者：
Highstein, SM
中科院分区：
文献类型：
--
作者：
Blazquez, PM;Hirata, Y;Highstein, SM
在视觉-前庭不匹配刺激期间前庭眼反射（VOR）的增益变化充当运动学习的模型系统。小脑小叶及其脑干（FTN）中的靶神经元是存储这些新VOR增益的候选者。我们最近研究了慢性VOR运动学习后垂直小叶浦肯野细胞的变化。最近，我们记录了Y神经元（垂直类型的FTNs）慢性VOR运动学习后，并将这些记录与垂直絮状浦肯野细胞的记录，以记录FTNs输入的任何变化，并了解Y神经元和垂直浦肯野细胞如何适应垂直VOR的一般模型。分析表明，在浦肯野细胞中观察到的变化没有转移到Y神经元，这表明它们的突触互连的增益被修改。我们量化了这两个群体的变化，并采用模拟来研究FTNs平行途径的变化，并提取了绒球在VOR适应中的作用。低增益适应比高增益适应导致更剧烈的变化，导致平行通路中头部速度敏感性的增加。模拟结果表明，小脑和脑干的可塑性都参与了新的VOR增益存储和絮状病变后获得的结果是不同的机制比那些在完整的动物的产品。
Gain changes in the vestibuloocular reflex (VOR) during visual-vestibular mismatch stimulation serve as a model system for motor learning. The cerebellar flocculus and its target neurons in the brain stem (FTN) are candidates for the storage of these novel VOR gains. We have recently studied the changes in vertical flocculus Purkinje cells after chronic VOR motor learning. Recently we recorded Y neurons ( a vertical type of FTNs) after chronic VOR motor learning and compared these records with vertical floccular Purkinje cells to document any changes in inputs to FTNs and understand how Y neurons and the vertical Purkinje cells fit into a general model for the vertical VOR. Analysis illustrates that the changes observed in Purkinje cells are not transferred to Y neurons, suggesting that the gain of their synaptic interconnection was modified. We quantified changes in both populations and employed simulations to study changes in parallel pathways to FTNs and to extract the role of the flocculus in VOR adaptation. Low-gain adaptation results in more drastic changes than its high-gain counterpart, causing increases in head velocity sensitivity in parallel pathways. Simulations suggest that cerebellar and brain stem plasticity both participate in novel VOR gain storage and that results obtained following floccular lesion are the product of different mechanisms than those operating in the intact animal.