Constant light during nursing causes delayed sleep patterns in mice with a Clock gene mutation

Constant light housing during lactation significantly caused a delayed onset of locomotor activity in Clock-mutant mice.

• Homozygote pups born from heterozygous dams exhibited a delayed activity onset compared to wild-type and heterozygote pups.
• Constant light conditions during lactation resulted in a lower number and delayed peak of specific cells in the suprachiasmatic nucleus.
• The degree of delay in activity onset was positively linked to the free-running period observed in constant darkness.
• Daily melatonin injections at lights-off normalized activity onset in Clock-mutant mice after exposure to constant light.
• Clock-mutant mice may serve as a model for understanding Delayed Sleep Phase Syndrome (DSPS).

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