Body clock genes outside the brain's main clock linked to daily movement patterns in rats

Chronic treatment of methamphetamine (MAP) in rats resulted in complete phase-reversal of certain clock gene expressions relative to a light-dark cycle.

• The activity rhythm in MAP-treated rats was desynchronized from the light-dark cycle.
• Expressions of the clock genes rPer1, rPer2, and rBMAL1 in the caudate-putamen and parietal cortex showed phase-reversal compared to control rats.
• Robust circadian rhythms of rPer1 expression in the suprachiasmatic nucleus were maintained in MAP-treated rats, similar to controls.
• Circadian rhythms of pineal and plasma melatonin levels did not show significant changes in MAP-treated rats.
• Desynchronization of clock gene expression was not observed in the nucleus accumbens and cingulate cortex.

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