Miyashita Y, Nagao S
Neurosci Res. 1984 Aug;1(4):223-41. doi: 10.1016/s0168-0102(84)80002-4.
The heterogeneous signal content of floccular Purkinje cell responses to optokinetic stimuli was analyzed in alert rabbits by means of selective lesions to brainstem pathways. Extracellular spike activities of Purkinje cells were recorded from rostral areas of the flocculus where local electrical stimulation elicited abduction of the ipsilateral eye. Chronic unilateral destruction of the nucleus reticularis tegmenti pontis, interrupting the visual mossy fiber afferent pathway to the flocculus, reduced the gain of the optokinetic eye movement (OKR) to one-third of the control. Concomitantly, simple spike responses of Purkinje cells to optokinetic stimuli were reduced to less than one-third of the control values. Severance of the visual climbing fiber afferent pathway by rostral inferior olivary lesions reduced the OKR gain little, and decreased the simple spike responses of the Purkinje cells only slightly. Bilateral lesions of the rostral half of the medial vestibular nucleus and rostro-ventral part of the lateral vestibular nucleus, which reduced the eye velocity in the OKR to less than one-third of the control value, did not induce any appreciable change in the simple spike responses of the Purkinje cells. It is concluded that visual mossy fiber signals are the most dominant factor which determines Purkinje cell responses to optokinetic stimuli, while visual climbing fiber signals and eye velocity mossy fiber signals make only subsidiary contributions.
通过对脑干通路进行选择性损伤,在清醒兔中分析了绒球浦肯野细胞对视动刺激的异质性信号内容。从绒球的前部区域记录浦肯野细胞的细胞外峰电位活动,在该区域局部电刺激可引起同侧眼外展。慢性单侧损毁脑桥被盖网状核,中断了至绒球的视觉苔藓纤维传入通路,使视动眼运动(OKR)增益降低至对照值的三分之一。与此同时,浦肯野细胞对视动刺激的简单峰电位反应降低至对照值的三分之一以下。通过损毁延髓下部橄榄核切断视觉攀缘纤维传入通路,对视动眼运动增益影响不大,仅使浦肯野细胞的简单峰电位反应略有降低。双侧损毁内侧前庭核头端半部和外侧前庭核头端腹侧部,使视动眼运动中的眼速度降低至对照值的三分之一以下,但并未引起浦肯野细胞简单峰电位反应的任何明显变化。得出的结论是,视觉苔藓纤维信号是决定浦肯野细胞对视动刺激反应的最主要因素,而视觉攀缘纤维信号和眼速度苔藓纤维信号仅起次要作用。