Related Experiment Video
Updated: Jun 23, 2026

Targeted Labeling of Neurons in a Specific Functional Micro-domain of the Neocortex by Combining Intrinsic Signal and Two-photon Imaging
Published on: December 12, 2012
Intrinsic chaos control in cortical circuits: A minimal E-I-M rate model for primary visual cortex
Mehdi Borjkhani1, Morteza A Sharif2, Hadi Borjkhani3
1International Centre for Translational Eye Research (ICTER), Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland. mborjkhani@ichf.edu.pl.
Cortical circuits operate near chaos, controlled by feedback mechanisms. This study models how feedback stabilizes neural activity, enabling flexible yet reliable brain function.
Area of Science:
- Computational neuroscience
- Systems neuroscience
- Neural dynamics
Background:
- Cortical circuits display variable yet bounded activity, hinting at operation near chaotic regimes.
- Understanding the mechanisms controlling neural dynamics is crucial for explaining brain function.
Purpose of the Study:
- To develop a minimal model of primary visual cortex (V1) circuits that explains how feedback mechanisms control neural chaos.
- To investigate the role of specific biological modifications in stabilizing V1 activity.
Main Methods:
- Developed a three-variable rate model based on the Lotka-Volterra system.
- Incorporated biologically motivated modifications: E→I feedback, homeostatic regulation, and orientation-tuned input.
- Analyzed model dynamics, compared results to V1 phenomena, and performed parameter space analysis.
Main Results:
- The model transformed chaotic dynamics into controlled limit cycles, reducing variance by 93%.
- Successfully reproduced V1 phenomena: orientation selectivity, stimulus-induced variability quenching, and realistic spiking irregularity.
- Feedback mechanisms were shown to stabilize activity across a wide parameter range.
Conclusions:
- Canonical feedback motifs in cortical circuits actively suppress intrinsic chaotic capacity.
- Brain function is positioned at an edge of instability, balancing computational flexibility with reliable processing.
- Specific disinhibition nonlinearities are key to achieving chaos-bounded dynamics.
Related Concept Videos
Neural Circuits
Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that...
Propagation of Action Potentials
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
Motor and Sensory Areas of the Cortex
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.
Hierarchy of Motor Control
