Subterranean rodents spend most of the day inside underground tunnels, where there is little daily change in colts dog collar environmental variables.Our observations of tuco-tucos (Ctenomys aff.knighti) in a field enclosure indicated that these animals perceive the aboveground light-dark cycle by several bouts of light-exposure at irregular times during the light hours of the day.
To assess whether such light-dark pattern acts as an entraining agent of the circadian clock, we first constructed in laboratory the Phase Response Curve for 1 h light-pulses (1000lux).Its shape is qualitatively similar to other curves reported in the literature and to our knowledge it is the first Phase Response Curve of a subterranean rodent.Computer simulations were performed with a non-linear limit-cycle oscillator subjected itski to a simple model of the light regimen experienced by tuco-tucos.
Results showed that synchronization is achieved even by a simple regimen of a single daily light pulse scattered uniformly along the light hours of the day.Natural entrainment studies benefit from integrated laboratory, field and computational approaches.