Research on input and output connections and amplitude control of saccadic eye movement by multiple electrode recording.

为了分析具有二维视网膜地形图的上丘的时空活动，研制了一种多通道神经单位活动数字信号同步连续记录系统。该系统由数字集成电路和计算机组成的手工电路组成，具有通道数不限，可连续长时间记录或触发间歇重复记录等优点。为了分析上丘视网膜标记图不同区域的传入和传出联系，提出了一种生物素化葡聚糖胺标记的单轴突三维重建方法，对单个轴突进行三维重建。在此之前，我试图在大鼠小脑中建立实验方法。我发现来自下橄榄核和外侧网状核的单个轴突经常支配小脑核。明确了这些单一轴突在小脑皮质和小脑核内的分支和神经支配模式。新的传入轴突被发现选择性地投射到小脑皮质的小脑核。这些轴突起源于延髓吻侧的旁正中网状结构。在小脑实验中，改进了明胶包埋、组织化学处理和组织反应室的制作方法，建立了实验方案。在上丘联系方面，我们发现大鼠小脑虫的内侧副橄榄尾侧部分的腹内侧部接受来自上丘的传入，然后投射到小叶VI和VII。

A simultaneous and continuous recording system of multi-channel digital signals of neural unitary activities was developed in order to analyze spatial and temporal activity of the superior colliculus that has two-dimensional retinotopical map. The system is composed of hand-made circuits of digital ICs and a computer and has advantages such as limitless channel number, and continuous long-time recording or triggered intermittent repetitive recording. Concerning the speed, 5 kHz sampling can be done with 256 channels in the continuous recording mode until the computere hard disk becomes full.A method of three-dimensional reconstruction of single axons by tracing with biotinylated dextran amine labeling was developed in order to analyze afferent and efferent connections in different areas in the retinotopical map in the superior colliculus. In advance, I tried to establish the methods in experiments in the rat cerebellum. I found that single axons originating from the inferior olivary nucleus and the lateral reticular nucleus frequently innervate the cerebellar nucleus. Branchings and innervation patterns of these single axons in the cerebellar cortex and cerebellar nucleus were clarified. A new afferent axons selective to the cerebellar nucleus that barely projected to the cerebellar cortex was found. These axons originated from the paramedian reticular formation in the rostral medulla. During the experiments in the cerebellum, methods for gelatin embedding and histochemical treatment and fabrication of tissue reaction chamber were improved and experimental protocol was established. Concerning superior collicular connections, it is was found that the ventromedial portion of the caudal part of the medial accessory olive, which was shown to receive afferent from the superior colliculus, then projected to lobule VI and VII in the rat cerebellar vermis.