Mean-field models are a powerful tool for understanding collective brain activity. A new model extends this approach by incorporating the exchange of ions between neurons and their surroundings, bringing important biological mechanisms into simulations of neuronal populations.

How can researchers simulate the activity of the whole brain without modeling every neuron in full detail? A new study, published in eLife, explores one part of the answer: retaining key biological mechanisms while simplifying the mathematics needed to model large neuronal populations.

The brain’s electrical activity depends on the movement of charged particles, called ions, across cell membranes and through the fluid surrounding neurons. These processes also influence one another: changes in ion concentration can affect how neurons fire and, in some circumstances, contribute to abnormal brain activity, including epileptic seizures.