Cortical plasticity induced by spike-triggered microstimulation in primate somatosensory cortex

Area of Science:

• Neuroscience
• Computational Neuroscience
• Neural Engineering

Background:

• Electrical stimulation, including deep brain stimulation, has therapeutic applications.
• Microstimulation is being explored to restore neural functions, but its effects on neural substrates are not fully understood.
• Understanding microstimulation's impact is crucial for developing effective neuroprosthetic devices.

Purpose of the Study:

• To investigate how microstimulation affects the primary somatosensory cortex (area 1).
• To compare the effects of spike-triggered microstimulation versus random microstimulation.
• To validate experimental findings using a computational model of the thalamocortical system.

Main Methods:

• Microstimulation and recording from microelectrode arrays in the hand area of the primary somatosensory cortex (area 1) in awake macaque monkeys.
• Application of random pulse stimulation and spike-triggered microstimulation to pairs of electrodes.
• Replication of the experimental setup using a detailed computer model of the thalamocortical system.

Main Results:

• Spike-triggered microstimulation induced cortical plasticity, evidenced by increased unit-pair mutual information.
• Random microstimulation did not induce significant cortical plasticity.
• Spike-triggered microstimulation led to enhanced response to touch and decreased neural variability.
• The computational model accurately reproduced the experimental findings.

Conclusions:

• Simple microstimulation protocols, particularly spike-triggered, can enhance somatosensory information flow.
• Spike-triggered microstimulation promotes beneficial neuroplastic changes in the somatosensory cortex.
• Computational modeling is a valuable tool for understanding and predicting the effects of neural stimulation.