A new research has demonstrated how the brain chemical dopamine regulates the rhythms of daily behaviour, which may have impact on activity and sleep patterns in Parkinson's disease.
Concordia research looks at role of dopamine in day-to-day routine by altering the activity of the 'clock-protein' PER2.
"PER2 is a protein well-known for its role in the regulation of daily or circadian rhythms, this is why it is referred to as a clock protein. Many molecules, such as stress hormones are known to have an impact on the activity of PER2. Until now, the role of dopamine in regulating circadian rhythms has been unclear," said Shimon Amir, the senior author and a psychology professor at the Concordia Center for Studies in Behavioural Neurobiology.
"Our findings show that not only is PER2 influenced by dopamine but also that dopamine is necessary for its rhythmic expression in specific brain regions," Amir added.
Dopamine is critical for normal movements and balance and its decreased level results in instability and involuntary movements, the telltale symptoms of Parkinson's.
The findings from this Concordia study may explain the disruptions of daily behavioural and physiological rhythms that are also frequently reported in Parkinson's.
Amir and his colleagues studied the role of dopamine in rats. Their first steps were to show that PER2 is present in a specific brain area that normally receive dopamine, namely the dorsal striatum, and that it fluctuates daily in this area.
"Our findings are consistent with the idea that the rhythm of expression of PER2 depends on the daily activation by dopamine," says first author Suzanne Hood, a doctoral student at Concordia.
The findings may have implications for individuals with Parkinson's disease with disrupted 24-hour rhythms of activity and sleep.
The study is published in the Journal of Neuroscience.