Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA.
J Exp Biol. 2021 May 15;224(10). doi: 10.1242/jeb.238386. Epub 2021 May 24.
To thrive, organisms must maintain physiological and environmental variables in suitable ranges. Given that these variables undergo constant fluctuations over varying time scales, how do biological control systems maintain control over these values? We explored this question in the context of phototactic behavior in larval zebrafish. We demonstrate that larval zebrafish use phototaxis to maintain environmental luminance at a set point, that the value of this set point fluctuates on a time scale of seconds when environmental luminance changes, and that it is determined by calculating the mean input across both sides of the visual field. These results expand on previous studies of flexible phototaxis in larval zebrafish; they suggest that larval zebrafish exert homeostatic control over the luminance of their surroundings, and that feedback from the surroundings drives allostatic changes to the luminance set point. As such, we describe a novel behavioral algorithm with which larval zebrafish exert control over a sensory variable.
为了茁壮成长，生物必须将生理和环境变量维持在适宜的范围内。鉴于这些变量在不同的时间尺度上不断波动，生物控制系统如何保持对这些值的控制？我们在幼虫斑马鱼的趋光行为背景下探讨了这个问题。我们证明，幼虫斑马鱼利用趋光性将环境亮度维持在设定点，当环境亮度变化时，该设定点的值会在秒的时间尺度上波动，并且它是通过计算视野两侧的平均输入来确定的。这些结果扩展了以前关于幼虫斑马鱼灵活趋光性的研究；它们表明，幼虫斑马鱼对周围环境的亮度施加了同态控制，并且来自周围环境的反馈驱动着亮度设定点的适应变化。因此，我们描述了一种新的行为算法，幼虫斑马鱼通过该算法对感官变量施加控制。
