Remote cortical perturbation dynamically changes the network solutions to given tactile inputs in neocortical neurons

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• The neocortex possesses a global network structure that constrains neuronal activity for any given input.
• The brain's internal state is multidimensional and dynamic, influencing neuronal responses to stimuli.
• Understanding how network structure and internal state interact is crucial for explaining perceptual capabilities.

Purpose of the Study:

• To investigate how remote, subthreshold electrical perturbations affect neuronal response constraints in the somatosensory cortex (SI).
• To determine if altering the internal cortical state can modify the range of possible neuronal activation patterns in response to tactile input.

Main Methods:

• Intracellular recordings were performed in SI neurons of anesthetized rats.
• Spatiotemporal tactile input patterns were applied to the somatosensory system.
• Remote, subthreshold electrical perturbations were used to modulate the internal cortical state.

Main Results:

• Normally, each tactile input pattern induced a wide range of preferred neuronal response states.
• Electrical perturbation induced novel response states that were not otherwise observed.
• Perturbation also made certain other response states less likely, altering the distribution of responses.

Conclusions:

• The physiological network structure of the cortex is not fixed but can dynamically change with the internal state of cortical regions.
• This dynamic modulation of network constraints by internal state allows for a richer, multifactorial perceptual capability.
• The findings suggest a mechanism for how the brain integrates internal state with external stimuli to generate perception.