Entrainment of circadian rhythms to irregular light/dark cycles: a subterranean perspective

• DOI: 10.1038/srep34264
• Publication Date: 2016-10-04T14:58:15Z
• Authors: Danilo E. F. L. F...; Milene G. Jannetti; Veronica S. Valen...; Gisele A. Oda
• Keywords: Entrainment (biomusicology); Chronobiology; Light Cycle; Darkness; Light Pollution

Abstract Synchronization of biological rhythms to the 24-hour day/night has long been studied with model organisms, under artificial light/dark cycles in laboratory. The commonly used rectangular cycles, comprising hours continuous light and darkness, may not be representative natural exposure for most species, including humans. Subterranean rodents live dark underground tunnels offer a unique opportunity investigate extreme mechanisms photic entrainment wild. Here, we show automated field recordings daily patterns South American subterranean rodent, tuco-tuco ( Ctenomys aff. knighti ). In laboratory, exposed tuco-tucos simplified version this pattern, determine minimum timing information that is necessary synchronization. As predicted from our previous studies using mathematical modeling, activity rhythm synchronized mostly regimen consisting single pulse per day, occurring at randomly scattered times within day length interval. Our integrated semi-natural, lab computer simulation findings indicate circadian oscillators robust, even face artificially reduced increased phase instability synchronizing stimuli.