演題詳細
Poster
小脳虫部垂プルキンエ細胞複雑スパイクの視運動刺激に対する応答特性
Complex spike response characteristics of Purkinje cells in the cerebellar uvula during optokinetic stimulation
- P1-135
- 北間 敏弘 / Toshihiro Kitama:1 駒形 純也 / Junya Komagata:2
- 1:山梨大学・総合分析実験センター / Center for Life Science Research, Univ of Yamanashi, Yamanashi, Japan 2:健康科学大学・理学療法学科 / Dept of Physical Therapy, Health Science University, Yamanashi, Japan
We have been studying the firing characteristics of Purkinje cells (P-cells) in the cerebellar nodulus and uvula of awake cats during sinusoidal head rotation in the vertical plane. The present study examined complex spike (CS) firing during optokinetic stimulation of the P-cells in the uvula. For visual-pattern rotation, a random dot pattern was presented on a monitor that was placed in front of the animal. The random-dot pattern was rotated sinusoidally in the horizontal, vertical, or torsional plane under the control of a computer. The stimulus parameters routinely used for each plane were a frequency of 0.25 Hz and a velocity of 6.28 °/s. In about forty percent of tested cells, a clear firing response was observed for CS activity during visual-pattern rotation in either the vertical or torsional plane, but not in the horizontal plane. The on-direction (stimulus direction that increases the firing rate) of CS firing was upward for cells responding to vertical-rotation and in an extorsional direction for cells responding to torsion-rotation. Velocity specificity was examined using stimulus velocities of 1.6-25.1°/s at a frequency of 0.25 Hz. CS modulation tended to increase with increasing stimulus velocities up to approximately 6.3-12.6°/s, but decreased with larger velocities. Frequency responses were examined using stimulus frequencies of 0.0625, 0.125, 0.25, 0.5, and 1.0 Hz, with a velocity of 6.3-12.6°/s, to evoke the maximal response in each P-cell. The response phases of CS modulation were approximately in phase with the stimulus velocities and the velocity gain had a similar range across the examined frequencies. These results suggest that each CS responds to a stimulus velocity with a specific direction.