Page T L
Department of Biology, Vanderbilt University, Nashville, Tennessee 37235.
J Biol Rhythms. 1990 Winter;5(4):273-89. doi: 10.1177/074873049000500401.
The temporal organization of locomotor activity was investigated in nymphs of the cockroach Leucophaea maderae. Approximately 40% of the animals examined between 1 and 50 days of age exhibited a circadian activity rhythm in constant darkness (n = 172) with an average free-running period of 23.7 +/- 0.68 hr. Twelve of 17 animals in which activity was recorded for most or all of the final instar also exhibited periods of rhythmic activity. The rhythms of the nymphs could be entrained by light-dark (LD) cycles with periods of 22, 24, or 26 hr. In contrast, neither maternal influences during embryogenesis nor hatching from the egg was effective in synchronizing the rhythms. Although adult cockroaches can be readily entrained by temperature cycles, in nymphs temperature appeared at best to be a weak zeitgeber. Embryonic exposure to an LD cycle until 6 days prior to egg hatch was effective in synchronizing the activity rhythms of the nymphs, indicating that differentiation of an entrainable pacemaking system occurs prior to hatching.
对马德拉蜚蠊若虫的运动活动的时间组织进行了研究。在1至50日龄的被检查动物中，约40%在持续黑暗环境中表现出昼夜活动节律（n = 172），平均自由运行周期为23.7 +/- 0.68小时。在17只记录了最后一龄若虫大部分或全部活动的动物中，有12只也表现出节律性活动期。若虫的节律可被周期为22、24或26小时的明暗（LD）循环所诱导。相比之下，胚胎发育期间的母体影响以及从卵中孵化均无法有效地使节律同步。虽然成年蜚蠊能够很容易地被温度循环所诱导，但在若虫中，温度充其量似乎只是一个较弱的授时因子。在卵孵化前6天之前对胚胎进行LD循环暴露可有效地使若虫的活动节律同步，这表明可诱导的起搏系统在孵化前就已分化。
