Velocity is an important determinant of the simple spike discharge of cerebellar Purkinje cells. In a previous study, Purkinje cells in the intermediate and lateral cerebellum recorded during manual tracking were found to be tuned to a combination of direction and speed, (i.e. preferred velocity). In this study a population analysis of this simple spike discharge was used to determine whether the velocity of tracking could be predicted. For the majority (30/32) of direction-speed combinations, the population response accurately specified the target velocity. A temporal analysis showed how the population response gradually converged to the required velocity 200 ms prior to the onset of tracking. Therefore, the simple spike discharge of a Purkinje cell ensemble contains sufficient information to reconstruct target velocity, providing support for the hypothesis that the cerebellum controls or signals movement velocity. (C) 2000 Elsevier Science Ireland Ltd.
Bibliographical noteFunding Information:
We wish to thank M. McPhee for assistance with graphics and histology and B. Welter and L. King for help with manuscript preparation. E. Ebner assisted in programming. This work was supported by National Institutes of Health grants 5R01-NS-18118 and F31-MH-1430, a National Science Foundation Grant, IBN-9873478 and a grant from the Human Frontier Science Program.
- Purkinje cells
- Simple spike