Rethinking Dopamine's Role in Movement and Its Impact on Parkinson's Treatment

A McGill-led study found that dopamine may function as an essential support system for movement rather than primarily modulating movement speed or force, reframing the neurotransmitter as a substrate that permits motor execution.

The prevailing view held that phasic dopamine bursts—brief, movement-linked spikes—drive motor vigor and thereby set movement speed and force. The new support-role framing instead positions dopamine as the enabling background tone the motor system requires to operate, not a moment-to-moment throttle. Clinically, that reframes some motor deficits as failures of movement support rather than mis-scaled burst signaling.

Elevating baseline dopamine improved movement capacity while manipulations of fast, phasic bursts produced minimal change in vigor during testing. The apparent negligible effect of burst manipulation reframes which neurochemical endpoints may map to functional recovery and may prompt trialists to prioritize baseline-dopamine endpoints in study design.