Thalamocortical relay fidelity varies across subthalamic nucleus deep brain stimulation protocols in a data-driven...

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a key therapy for Parkinson's disease.
• STN-DBS effectiveness may involve modulating basal ganglia outputs, particularly the internal segment of the globus pallidus (GPi).
• Altered GPi activity impacts thalamic targets, potentially disrupting basal ganglia-thalamocortical (TC) processing.

Purpose of the Study:

• To investigate how STN-DBS affects thalamic activity, specifically TC relay cell responses.
• To model the impact of altered GPi inhibition on TC relay fidelity in parkinsonian states.

Main Methods:

• Utilized a computational model to simulate TC relay cell responses to excitatory inputs.
• Incorporated inhibitory signals derived from GPi recordings in normal and parkinsonian monkeys (MPTP-induced).
• Simulated GPi activity under no STN-DBS, sub-therapeutic STN-DBS, and therapeutic STN-DBS conditions.

Main Results:

• Parkinsonian GPi inhibition without DBS compromised TC relay fidelity compared to normal conditions.
• Therapeutic STN-DBS significantly improved TC relay fidelity, whereas sub-therapeutic DBS did not.
• In a heterogeneous TC cell model, response failures were more frequent without DBS than with therapeutic DBS or in normal conditions.

Conclusions:

• STN-DBS alters parkinsonian GPi activity to enhance TC relay fidelity.
• This modulation of GPi-thalamic pathways is a plausible mechanism for STN-DBS therapeutic effects in Parkinson's disease.
• Computational modeling provides insights into the network-level effects of STN-DBS.