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局部图的上丘的时空活动，研制了一种同时连续记录神经单一活动的多通道数字信号系统。该系统由数字集成电路和计算机手工制作电路组成，具有无限通道数、连续长时间记录或触发间歇重复记录等优点。在速度方面，在连续记录模式下，可以用256个通道进行5khz采样，直到计算机硬盘满为止。为了分析上丘视网膜局部图中不同区域的传入和传出连接，采用生物素化右旋糖酐胺标记法对单轴突进行三维重建。在此之前，我尝试在大鼠小脑中建立实验方法。我发现起源于下橄榄核和外侧网状核的单轴突经常支配小脑核。明确了这些单轴突在小脑皮层和小脑核中的分支和神经支配模式。一个新的传入轴突选择性的小脑核，几乎投射到小脑皮层。这些轴突起源于延髓吻侧的旁系网状结构。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制作的方法，并建立了实验方案。在上丘连接方面，我们发现大鼠小脑蚓部内侧副橄榄尾侧的腹内侧部分接受上丘的传入信号，然后投射到第六小叶和第七小叶。

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.