New evidence challenges understanding of 笔补谤办颈苍蝉辞苍鈥檚 disease聽
A 9I制作厂免费-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.聽
Published in聽聽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.聽
鈥淥ur findings suggest we should rethink dopamine鈥檚 role in movement,鈥� said senior author聽Nicolas Tritsch,聽Assistant Professor in 9I制作厂免费鈥檚 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.鈥澛�
Dopamine is known to be important for motor聽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,聽tremors聽and balance issues.聽
The standard treatment for 笔补谤办颈苍蝉辞苍鈥檚, Levodopa, helps restore movement, but聽why聽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聽vigour.聽
The new study points in the opposite direction.聽聽
鈥淩ather than acting as a throttle that sets movement speed, dopamine appears to function more like engine oil.聽It鈥檚聽essential for the system to run, but not the signal that聽determines聽how fast each action is executed,鈥� said Tritsch.聽
Measuring dopamine in real time聽
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.聽
If fast dopamine bursts did control聽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.聽
A more precise target for treatment聽
聽a number projected to more than double by 2050 as the population ages.聽
A clearer explanation for why levodopa is effective opens the door to new therapies designed to聽maintain聽baseline dopamine levels, the authors note.聽
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.聽
About the study聽
鈥溾�� by聽Haixin聽Liu and Nicolas Tritsch et al., was published in聽Nature Neuroscience.聽
The study was funded by the Canada First Research Excellence Fund, awarded through the Healthy Brains, Healthy Lives initiative at 9I制作厂免费 and the Fonds de Recherche du Qu茅bec.聽
