Layers of the monkey visual cortex are selectively modulated during electrical stimulation

Area of Science:

• Neuroscience
• Computational Neuroscience

Background:

• The mammalian neocortex has six distinct cellular layers crucial for sensory processing.
• Laminar recordings of local field potentials (LFPs) are vital for studying neural activity within cortical layers.
• Layer-specific effects of electric brain stimulation on LFPs are not well understood.

Purpose of the Study:

• To investigate the layer-specific effects of electric stimulation on LFPs in the primary visual cortex.
• To determine how electrical stimulation modulates visual-evoked potentials in different cortical layers.

Main Methods:

• Recorded laminar LFPs from capuchin monkeys' primary visual cortex during visual stimulation.
• Applied low-frequency sinusoidal electric current to the occipital lobe.
• Analyzed phase-dependent modulation of visual-evoked potentials relative to electric stimulation.

Main Results:

• Deeper cortical layers exhibited phase-dependent changes in LFPs relative to electric stimulation.
• Superficial cortical layers did not show significant phase-dependent LFP changes.
• A cortical column model supported these findings, attributing them to deeper layer neuronal driving forces.

Conclusions:

• Electrical stimulation selectively modulates deeper cortical layers.
• Findings provide insight into targeted neuromodulation of specific cortical layers.
• This research advances understanding for more precise brain stimulation applications.