Dim scotopic illumination accelerates the reentrainment following simulated jetlags in a diurnal experimental model, Drosophila

Abstract

Jetlag results from the misalignment between the endogenous circadian timing and the civil timing after a transmeridian flight. Efficacy of the dim nocturnal illumination (0.03 lx) in accelerating the reentrainment following simulated jetlags in Drosophila biarmipes was examined by subjecting the flies to 24 h light-dark cycles in which the 12 h photophase was at 300 lx for all flies but the scotophase was at 0 and 0.03 lx for the control and experimental flies, respectively. Reentrainment was always faster in the experimental flies than the control ones. Moreover, unlike melatonin, the dimly lit nights accelerated the reentrainment following both, the phase advance and delay of the light-dark cycles. This study might have potential application as a non-drug jetlag treatment.

The Effects of Artificial Night Lighting on Tail Regeneration and Prey Consumption in a Nocturnal Salamander (Plethodon cinereus) and on the Behavior of Fruit Fly Prey (Drosophila virilis)

“…The flies in that study appeared to have a dim light preference and did not simply become active for more hours a day but shifted their initiation of activity from the morning period (M) to the evening period (E). In another species of fruit fly, Drosophila ( Sophophora ) biarmipes , dim light (0.03 lx) at night sped up re-entraintment (recovery of normal circadian pattern) after rhythm disruption more effectively than did total darkness [ 81 ]. Similar effects of dim lighting have been observed in Syrian hamsters ( Mesocricetus auratus ), where nocturnal illumination of 0.004 lx (equivalent to dim moonlight) was sufficient to accelerate re-entrainment relative to total darkness after disruption of circadian cycles [ 82 ], demonstrating that even small amounts of light during scotophase can alter periodic locomotor rhythms, when compared to what occurs in studies that employ total darkness as a control treatment.…”

“…Similar effects of dim lighting have been observed in Syrian hamsters ( Mesocricetus auratus ), where nocturnal illumination of 0.004 lx (equivalent to dim moonlight) was sufficient to accelerate re-entrainment relative to total darkness after disruption of circadian cycles [ 82 ], demonstrating that even small amounts of light during scotophase can alter periodic locomotor rhythms, when compared to what occurs in studies that employ total darkness as a control treatment. It has been suggested that such an effect might be caused by dim lighting disrupting the coupling between the M and E oscillators [ 81 ], though data for mice ( Mus musculus ) at least indicate that this effect is mediated by clock genes outside the SCN [ 83 ]. Regardless of the mechanism, dALAN is able to alter periodic locomotor behavior in multiple species of fruit flies and in mammals.…”