Decorrelated neuronal firing in cortical microcircuits

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Correlated variability between neurons reflects functional connectivity.
• Cortical columns are thought to have densely connected neurons with shared inputs.
• Previous studies indicate high correlated variability between nearby neurons.

Purpose of the Study:

• To reexamine correlated variability between nearby neurons in the primary visual cortex.
• To challenge existing models of cortical microcircuitry and function.

Main Methods:

• Development of chronically implanted multitetrode arrays for high-quality neural recordings.
• Recording neural activity in the primary visual cortex of awake macaques.
• Analysis of trial-to-trial variability in nearby neurons with similar orientation tuning.

Main Results:

• Nearby neurons with similar orientation tuning exhibit virtually no correlated variability.
• This finding contrasts with previous reports of high correlated variability.

Conclusions:

• Current models of cortical microcircuit architecture and function require refinement.
• Adjacent neurons may share minimal common input or actively decorrelate their activity.