GABA storage and release from direct pathway neurons account for the enhanced short-duration response of L-dopa in Parkinson's disease

•L-dopa treatment for Parkinson's disease provides rapid and long-term effects. •The short-duration response increases after chronic repetitive L-dopa treatment. •Repetitive L-dopa treatment in model rats increased GABA storage and release in GPi. •L-dopa effect is determined by amount of GABA released from direct pathway neurons. •Increased GABA release to GPi is the mechanism underlying an increased SDR.