Striatal spreading depolarization: Possible implication in levodopa-induced dyskinetic-like behavior

Area of Science:

• Neuroscience
• Neurophysiology
• Parkinson's Disease Research

Background:

• Spreading depolarization (SD) is a wave of neuronal activity linked to cortical conditions like stroke and epilepsy.
• SD in the striatum, crucial for motor control and Parkinson's disease (PD) pathophysiology, remains understudied.
• Understanding striatal SD mechanisms is vital for PD and related motor disorders.

Purpose of the Study:

• To investigate the roles of glutamatergic and dopaminergic neurotransmission in initiating striatal spreading depolarization.
• To explore how Parkinson's disease and l-dopa treatment affect striatal SD.

Main Methods:

• Utilized a novel approach combining optical imaging and measurements of endogenous dopamine (DA) levels.
• Employed pharmacological and molecular analyses to dissect the mechanisms of striatal SD.
• Investigated experimental models of Parkinson's disease and l-dopa treatment.

Main Results:

• Striatal SD necessitates the simultaneous activation of D1-like dopamine receptors and N-methyl-D-aspartate receptors.
• SD occurrence and propagation speed are reduced in experimental Parkinson's disease.
• Chronic l-dopa treatment exacerbates striatal SD in parkinsonian models, impacting D1 receptor signaling pathways.

Conclusions:

• Striatal spreading depolarization is modulated by dopaminergic and glutamatergic systems.
• Altered striatal SD may contribute to abnormal basal ganglia activity, particularly in l-dopa-induced dyskinesia.
• Striatal SD presents a potential therapeutic target for movement disorders.