Critical Fusion Frequency in Single Retina Cells of the Squilla Compound Eye

口脚類シャコ複眼の単一視細胞に,微小電極を刺入して脱分極性受容器電位を誘導し,これを指標に断続光に対する臨界融合頻度(CFF)を測定した。透明な回転円板に,面積と濃度を異にする扇形の減光フィルターをとりつけた明暗相の周期比及び明暗相の照度比の異なる6種類のセクターを用いた。光強度,照度比の増加及び周期比の減少は,それぞれCFFを高めることが見出された。シャコ複眼では,最良条件下におけるCFFは約70Hzとなり,slow typeに属すると結論される。矩形波断続光には刺激光強度,周期比,照度比及び周波数の4変数が含まれる。フーリエ変換により,矩形波を正弦波に変えると,4変数は平均照度,比振巾及び周波数の3変数に置換でき,それぞれが独立した光強度,振動巾及び時間の3因子になることが示唆された。The critical fusion frequency (CFF) was determined using the compound eye of the marine crustacean Squilla oratoria. A microelectrode was inserted into a single retina cell in, which the depolarizing potentials were induced. The flickering light was given by rotating the sector made of a transparent disk to which the fanshaped filters were attached. Six types of the sector were designed by changing area and density of the filter. Under the most favourable conditions the CFF of S. oratoria compound eye was about 70Hz. It was concluded that the species belonged to the slow type. The square wave of the flickering light involved four parameters: light intensity (Lmax), pulse to cycle fraction (PCF), illuminance ratio (IR) and frequency. The square wave could be transformed into the sine wave by applying the following equations (Fourier transformation): R=(Lmax・T・P+L(T-T・P))/(Lmax・T) 0<P