20 research outputs found
Isolation and Characterization of a Highly Siderophore Producing Bacillus subtilis Strain
Bioaugmentation-Assisted Phytostabilisation of Abandoned Mine Sites in South West Sardinia
Influence of dietary Soy Isoflavones Genistein and Daidzein on Genotoxicity and Mammary Carcinogenicity in Rats Exposed to the Model Carcinogen 7,12-Dimethylbenz[a]anthracene (DMBA)
Validation of a food frequency questionnaire measurement of dietary acrylamide intake using hemoglobin adducts of acrylamide and glycidamide
Lethal and sublethal exposure of Hemichromis bimaculatus (Gill, 1862) to malachite green and possible implications for ornamental fish
Methylphenidate Modifies the Motion of the Circadian Clock
People with attention-deficit/hyperactivity disorder (ADHD) often experience sleep problems, and these are frequently exacerbated by the methylphenidate they take to manage their ADHD symptoms. Many of the changes to sleep are consistent with a change in the underlying circadian clock. The present study was designed to determine if methylphenidate alone could alter properties of the circadian clock. Young male mice were examined in light–dark cycles and in constant darkness and recordings were performed on behavioral activity, sleep, and electrical activity in the suprachiasmatic nucleus (SCN) of freely moving mice. Methylphenidate in the drinking water (0.08%) significantly increased activity in the mid-to-late night, and led to a delay in the onset of activity and sleep relative to the light–dark cycle. While locomotor levels returned to baseline after treatment ended, the phase angle of entrainment required at least a week to return to baseline levels. In constant darkness, the free-running period of both wheel-running and general locomotor rhythms was lengthened by methylphenidate. When the treatment ended, the free-running period either remained stable or only partially reverted to baseline levels. Methylphenidate also altered the electrical firing rate rhythms in the SCN. It induced a delay in the trough of the rhythm, an increment in rhythm amplitude, and a reduction in rhythm variability. These observations suggest that methylphenidate alters the underlying circadian clock. The observed changes are consistent with clock alterations that would promote sleep-onset insomnia