PDF(Pubmed)
Abstract：
At the start of a journey home or to a foraging site, ants often stop, interrupting their forward movement, turn on the spot a number of times, and fixate in different directions. These scanning bouts are thought to provide visual information for choosing a path to travel. The temporal organization of such scanning bouts has implications about the neural organisation of navigational behaviour. We examined (1) the temporal distribution of the start of such scanning bouts and (2) the dynamics of saccadic body turns and fixations that compose a scanning bout in Australian desert ants, Melophorus bagoti, as they came out of a walled channel onto open field at the start of their homeward journey. Ants were caught when they neared their nest and displaced to different locations to start their journey home again. The observed parameters were mostly similar across familiar and unfamiliar locations. The turning angles of saccadic body turning to the right or left showed some stereotypy, with a peak just under 45°. The direction of such saccades appears to be determined by a slow oscillatory process as described in other insect species. In timing, however, both the distribution of inter-scanning-bout intervals and individual fixation durations showed exponential characteristics, the signature for a random-rate or Poisson process. Neurobiologically, therefore, there must be some process that switches behaviour (starting a scanning bout or ending a fixation) with equal probability at every moment in time. We discuss how chance events in the ant brain that occasionally reach a threshold for triggering such behaviours can generate the results.
摘要：
在回家或觅食地点的旅程开始时，蚂蚁经常停下来，打断他们的前进,在现场转了几次，并固定在不同的方向。这些扫描回合被认为为选择行进路径提供了视觉信息。这种扫描回合的时间组织对导航行为的神经组织有影响。我们检查了（1）这种扫描回合开始的时间分布，以及（2）构成澳大利亚沙漠蚂蚁扫描回合的扫视身体转向和注视的动力学，米洛普斯·巴博蒂，当他们在回家的旅程开始时，从一个有围墙的通道走到开阔的田野上。蚂蚁在接近巢穴时被抓住，并流离失所到不同的地方再次开始回家的旅程。观察到的参数在熟悉和不熟悉的位置大多相似。扫视身体向右或向左转动的转向角度显示出一些刻板印象，峰值低于45°。这种扫视的方向似乎是由其他昆虫物种所述的缓慢振荡过程决定的。在时间上，然而,扫描间隔和个体固定持续时间的分布均显示出指数特征，随机速率或泊松过程的签名。神经生物学，因此,必须有一些过程可以在每个时刻以相等的概率切换行为（开始扫描回合或结束固定）。我们讨论了蚂蚁大脑中偶尔达到触发此类行为的阈值的偶然事件如何产生结果。
