Loss of light-based clock resetting and changed natural daily rhythms in math5-deficient mice

math5-/- mutant mice exhibit a free-running circadian rhythm period of approximately 24.43 hours, which is about 1 hour longer than control mice.

• math5-/- mice lack an identifiable retinohypothalamic tract pathway due to the underdevelopment of retinal ganglion cells.
• These mutant mice do not show any entrainment to light/dark cycles, unlike heterozygote mice that exhibit normal entrainment.
• The free-running period of math5-/- mice is significantly prolonged compared to controls, indicating altered circadian timing.
• math5-/- mice have a reduced capacity to adjust their rhythms to non-light cues, such as restricted running wheel access.
• Despite their altered rhythms, math5-/- mice can still exhibit free-running behavior and anticipatory responses under certain conditions, suggesting an alternative timing mechanism.

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