Daily rhythm of body temperature in diabetic animals. Representative double-plot thermograms of BT in late-treated animals (top row) and early-treated animals (bottom row) with insulin (A, D), melatonin (B, E) or a combination of both hormones (C, F). Red to yellow coloration indicates higher temperatures and black to grey coloration indicates lower temperatures throughout 55 days of record in 30 seconds bins. Black and white rectangles under the thermograms indicate the LD cycle maintained during the experiments. Late treated animals, (A-C): control period (lateral top white bar), long-term diabetic period (lateral black bar), and treated period (bottom white bar). Early treated animals (D-F):short-term diabetic period (lateral top black bar), early treatment (top white bar), off-treatment period (bottom black bar) and restituting treatment period (bottom white bar). The white arrow indicates the moment of the STZ injection.