Cortical stimulation relieves parkinsonian pathological activity in vitro

Area of Science:

• Neuroscience
• Systems neuroscience
• Computational neuroscience

Background:

• Chemical excitatory drives like N-methyl-d-aspartate (NMDA) activate striatal microcircuits, creating alternating neuronal ensemble activity and temporal sequences.
• Dopamine-depleted striatal microcircuits exhibit increased spontaneous activity with dominant recurrent ensembles, disrupting temporal sequences and correlating with Parkinsonian pathology.

Purpose of the Study:

• To investigate if cortical stimulation can evoke similar network activity as chemical drives in the striatal microcircuit.
• To determine if cortical stimulation can ameliorate pathological activity in dopamine-depleted striatal microcircuits.
• To explore the effects of combining cortical stimulation with L-DOPA treatment on parkinsonian activity.

Main Methods:

• Utilized dynamic calcium imaging in mouse brain slices to monitor the activity of multiple neurons with single-cell resolution.
• Applied trains of electrical stimuli to the cortex to evoke network responses.
• Investigated the impact of cortical stimulation on dopamine-depleted striatal microcircuits, both with and without L-DOPA.

Main Results:

• Cortical stimulation induced network activity comparable to NMDA application in healthy striatal microcircuits.
• In dopamine-depleted circuits, cortical stimulation temporarily suppressed pathological activity by altering neuronal ensemble dynamics, restoring transitions between network states.
• Combined cortical stimulation and L-DOPA treatment eliminated parkinsonian activity throughout the recording period.

Conclusions:

• Cortical stimulation can effectively modulate aberrant neuronal activity in dopamine-depleted striatal circuits.
• This modulation restores network dynamics towards a healthy state, offering a potential therapeutic strategy for Parkinson's disease.
• Cortical stimulation may enable reduced L-DOPA dosages in Parkinson's disease treatment.