New evidence challenges understanding of 笔补谤办颈苍蝉辞苍鈥檚 disease听
A 麻豆传媒网站-led study is challenging a popular theory about how dopamine drives movement, a discovery that could shift how scientists think about 笔补谤办颈苍蝉辞苍鈥檚 disease treatments.听
Published in听听the research found dopamine does not set the speed or force of each movement, as had been thought. Instead, it appears to act as the underlying support system that makes movement possible.听
鈥淥ur findings suggest we should rethink dopamine鈥檚 role in movement,鈥� said senior author听Nicolas Tritsch,听Assistant Professor in 麻豆传媒网站鈥檚 Department of Psychiatry and researcher at the Douglas Research Centre. 鈥淩estoring dopamine to a normal level may be enough to improve movement. That could simplify how we think about 笔补谤办颈苍蝉辞苍鈥檚 treatment.鈥澨�
Dopamine is known to be important for motor听vigour, which is the ability to move with strength and speed. In 笔补谤办颈苍蝉辞苍鈥檚 patients, dopamine-producing neurons deteriorate, leading to slower movement,听tremors听and balance issues.听
The standard treatment for 笔补谤办颈苍蝉辞苍鈥檚, Levodopa, helps restore movement, but听why听it works is not well understood. In recent years, advanced tools detected fast dopamine spikes during movement, which led many to believe these spikes control听vigour.听
The new study points in the opposite direction.听听
鈥淩ather than acting as a throttle that sets movement speed, dopamine appears to function more like engine oil.听It鈥檚听essential for the system to run, but not the signal that听determines听how fast each action is executed,鈥� said Tritsch.听
Measuring dopamine in real time听
The researchers measured brain activity in mice as they pressed a weighted lever, turning dopamine cells 鈥渙n鈥� or 鈥渙ff鈥� using a light-based technique.听
If fast dopamine bursts did control听vigour, changing dopamine at that moment should have made movements faster or slower. To their surprise, it had no effect. In tests with levodopa, they found the medication worked by boosting the brain鈥檚 baseline level of dopamine, not by restoring the fast bursts.听
A more precise target for treatment听
听a number projected to more than double by 2050 as the population ages.听
A clearer explanation for why levodopa is effective opens the door to new therapies designed to听maintain听baseline dopamine levels, the authors note.听
It also encourages a fresh look at older therapies. Dopamine receptor agonists have shown promise but caused side effects because they acted too broadly in the brain. The new finding offers scientists a sense of how to design safer versions.听
About the study听
鈥溾�� by听Haixin听Liu and Nicolas Tritsch et al., was published in听Nature Neuroscience.听
The study was funded by the Canada First Research Excellence Fund, awarded through the Healthy Brains, Healthy Lives initiative at 麻豆传媒网站 and the Fonds de Recherche du Qu茅bec.听