Fig. 1.

Experimental paradigm. Animals previously exposed to 12:12 hr light:dark (LD) cycles with feeding restricted to the photophase were subjected to T-cycles of 22 hr with 11:11 hr light: DimLight for 6 wk. Animals were fed twice during the photophase, 1 hr after lights ‘ON’ and 1 hr prior to lights ‘OFF’. During stage 2, animals were either treated with melatonin chronically or vehicle alone in drinking water provided freshly during feeding time. Finally, animals were subjected to constant dim light conditions. During stage 3, the feeding cycle was maintained according to the previous 11:11 hr LDim cycles.