猫外侧膝状体周核神经元对正弦光栅刺激的反应特性

以正弦光栅研究了猫外侧膝状体周核(Perigeniculate Nuclells,PGN)神经元的空间频率和朝向调谐特性,以及空间总和性质.通常,PGN神经元空间频率调谐可分带通和低通二类.朝向特性可分为较宽范围朝向选择、无朝向选择和不规则朝向选择三类.用对比度翻转(ContrastReversal Grating(的光栅刺激时,少部分细胞存在零相位位置(Null Phase Positions),大多数呈现“二倍频”反应(Frequency Doubling Response).实验说明PGN神经元可能存在-X类型和-Y类型.

THE RESPONSE CHARACTERISTICS OF CAT'S PERIGENICULATE NEURONS TO SINUSOIDAL GRATING STIMULI

Single unit activities were recorded from PGN region with tungsten-in-glass electrodes on the anesthetized and paralyzed cats. The spatial frequency, orientation tunings and spatial summation properties of PGN neurons were determined with drifting sinusoidal grating. Two types, bandpass and lowpass of spatial frequency properties, could be identified. Three types of orientation specificity could be classified: broad-orientation-tuning, non-orientation-tuning and irregular-orientation-tuning. Minor cells had null phase positions, most presented frequency doubling response to contrast reversal grating. The experiment suggests that X-like and Y-like subgroups maybe exist in PGN.