Plane Specific Purkinje Cell Responses to Vertical Head Rotations

23 We recorded simple spike (SS) and complex spike (CS) firing of Purkinje cell in the cerebellar 24 nodulus and uvula of awake head-restrained cats during sinusoidal vertical rotation of the head 25 in four stimulus planes (pitch, roll, and two vertical canal planes). Two SS response types 26 (positionand velocity-types) with response phases close to those of head position and velocity, 27 respectively, were recognized. Optimal response planes and directions for SS and CS of each 28 cell were estimated from the response amplitudes in the four stimulus planes by fitting with a 29 sinusoidal function. The principal findings are as follows: 1) two rostrocaudally oriented 30 functional zones of Purkinje cells can be distinguished; 2) the medially located parasagittal 31 band is active during rotation in the pitch plane; 3) the laterally located band is active during 32 rotation in the roll plane. These two zones are the same as previously reported zones in the 33 cerebellar flocculus active during head rotation in the canal planes in the point that both 34 cerebellar sagittal zones are plane specific functional zones, suggesting that the anatomical 35 sagittal zones serve as functional plane-specific zones at least in the vestibulocerebellum. 36