J. S. Risien Russell

Phenomena Resulting from Interruption of Afferent and Efferent Tracts of the Cerebellum

I am greatly indebted to Professor Victor Horsley for allowing me to carry out the investigations, the results of which are embodied in this paper, in the Pathological Laboratory of University College, London. My object in undertaking this research, was twofold, as I wished in the first place to obtain evidence in support of or against the view that the cerebellum exercises a direct influence on the spinal centres, as opposed to any indirect influence exerted through the agency of the cerebral cortex, and in the second place to ascertain whether any descending tract could be traced from the cerebellum, by way of which any such direct influence could be brought to bear on the spinal centres. It is, however, impossible for me to do more than deal with the first of these problems in the present paper.

The origin and destination of certain afferent and efferent tracts in the medulla oblongata

In attempting to arrive at definite conclusions with regard to the origin and destination of some of the afferent and efferent tracts which exist in the medulla oblongata, the following experimental procedures were adopted.

Phenomena resulting from interruption of afferent and efferent tracts of the cerebellum

The research was undertaken in the hope of obtaining evidence in support of or against the view that the cerebellum exercises a direct influence on the spinal centres, as opposed to any indirect influence exerted through the agency of the cerebral cortex. The inferior peduncle of the cerebellum was accordingly divided on one side, the organ itself and its other peduncles being otherwise left intact, and the results obtained by this procedure were controlled by experiments in which the lateral tracts of the medulla oblongata were divided on one side without injury to the pyramid on the one hand or to the posterior columns and their nuclei on the other. Further control experiments consisted in dividing transversely the posterior columns and their nuclei a few millimetres above the calamus scriptorius, on one side, without including the lateral tracts of the medulla in the lesion.