Daily molecular clock patterns in the thinking and movement areas of the mouse brain

Clock genes exhibit circadian rhythms in the neocortex and cerebellum of the mouse brain, with a 5-hour delay compared to the suprachiasmatic nucleus.

• All six layers of the mouse neocortex and the Purkinje and granular cell layers of the cerebellum express clock genes.
• The expression of specific clock genes, including Per1, Per2, Cry1, Arntl, and Nr1d1, suggests the presence of local circadian oscillators within these brain regions.
• The temporal expression profiles of clock genes in the neocortex and cerebellum are similar but delayed by 5 hours relative to those in the suprachiasmatic nucleus.
• ARNTL protein products are found in neurons of both the mouse neocortex and cerebellum, indicating active molecular clockwork in these areas.
• These observations suggest a potential master-slave relationship between the suprachiasmatic nucleus and peripheral brain oscillators.

Simplified