Microstimulation in the primary visual cortex: activity patterns and their relation to visual responses and evoked...

Area of Science:

• Neuroscience
• Visual Cortex Research
• Neural Stimulation

Background:

• Intracortical microstimulation (ICMS) in the primary visual cortex (V1) elicits phosphenes and saccades.
• The spatio-temporal neural activity patterns evoked by ICMS remain unquantified.
• The relationship between ICMS-evoked activity, visual responses, and saccade generation is unclear.

Purpose of the Study:

• To measure the spatio-temporal neural activity patterns evoked by ICMS in V1.
• To compare ICMS-evoked neural responses with those from visual stimuli.
• To investigate the relationship between ICMS-evoked neural activity and saccade generation.

Main Methods:

• Combined ICMS with voltage-sensitive dye imaging in behaving monkeys.
• Measured neural activity at high spatial (meso-scale) and temporal resolution in V1.
• Compared population responses to ICMS and small visual stimuli.

Main Results:

• Both ICMS and visual stimuli evoked population activity spreading across millimeters in V1 and to extrastriate areas.
• ICMS-evoked responses showed faster activation transients and wave-like horizontal propagation.
• Neural activity was higher during ICMS trials with evoked saccades compared to those without.

Conclusions:

• This study reveals the spatio-temporal dynamics of neural activity evoked by ICMS in V1.
• ICMS-evoked patterns differ in temporal dynamics and propagation compared to visual stimuli.
• ICMS-evoked neural activity is linked to saccade generation, providing insights into visual processing and sensorimotor control.