Purkinje cells in the cerebellum: their responses to postural stimuli in cats.

The responses of Purkinje cells in the cerebellum produced by various positions of the limbs were studied in decerebrated unanesthetized cats. The majority of units located in the intermediate zone of the anterior lobe selectively reacted to definite postures of the limbs: some of them were active when a given limb was in an extended position and were silent when it was in flexion; the other ones, on the contrary, were active when the limb was flexed and silent when it was extended. The rate of discharges was in both cases the same and amounted to 40 to 80 per second. It did not change with the lapse of time, and remained the same when flaxedil was administered. These results, in connection with some other data, seem to explain the problem of how the cerebellum transforms the information about the tensions of tendons and muscles, delivered by the tendon organs and muscle spindles, respectively, into the information about movements.