Endogenous rhythmicity of Bmal1 and Rev‐erbα in the hamster pineal gland is not driven by norepinephrine

Per1 and Cry2 gene expression in the pineal gland increases nocturnally and is regulated by norepinephrine.

• The expression of Per1 and Cry2 mRNA levels rises at night and remains elevated in constant darkness, but is suppressed in constant light.
• Administration of the adrenergic antagonist propranolol eliminates the nocturnal increase in Per1 and Cry2 expression.
• Bmal1 and Rev-erb alpha mRNA levels show daily variation, peaking at midday and during the transition from day to night, respectively.
• The daily variation of Bmal1 and Rev-erb alpha expression is maintained in constant light and is unaffected by propranolol.
• This research confirms the role of norepinephrine in regulating Per1 and Cry2 expression while identifying a circadian rhythm for Bmal1 and Rev-erb alpha that operates independently of norepinephrine.

AI simplified