Signatures of Covert Neuron Loss in the Local Field Potential of Motor Cortex

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Covert stroke, occurring 10 times more frequently than symptomatic stroke, significantly contributes to the global disease burden.
• The neuroelectrophysiological impact of covert stroke remains understudied compared to symptomatic stroke.
• This study investigates whether covert stroke replicates the neuroelectrophysiological spectrum impact of symptomatic stroke.

Purpose of the Study:

• To explore the neuroelectrophysiological consequences of covert neuron loss.
• To investigate the sensitivity of the neural spectrum to neuron loss.
• To bridge the understanding between covert and symptomatic stroke regimes.

Main Methods:

• Electrolytic lesions were induced in the motor cortex of large animals during a multimonth arm reaching task.
• Behavioral metrics and local field potential features (bandpowers, aperiodic/periodic parameters, time-frequency tensors) were analyzed.
• State space modeling and nonparametric permutation tests were employed to assess the effects of lesions.

Main Results:

• Lesions did not affect task success, but altered aperiodic structure.
• A decrease in gamma bandpower and an amplification of sensorimotor rhythms (8-45 Hz) were observed.
• Neural perturbations, particularly in gamma and sensorimotor rhythms, persisted longer than behavioral effects.

Conclusions:

• The neural spectrum exhibits higher sensitivity to neuron loss than previously recognized.
• Covert stroke may elicit measurable responses within the neural spectrum.
• Electrolytic lesioning serves as a valuable tool for studying neuron loss and advancing causal understanding of post-stroke effects.