# Synaptic Tuning of Brain Rhythms: From Chemical Signalling to Cortical Oscillations

## TL;DR

This paper explains how different brain regions produce specific rhythms based on the balance of excitatory and inhibitory receptors.

## Contribution

The study links EEG data from epilepsy patients with receptor density maps to explain regional brain oscillations.

## Key findings

- Regional oscillations depend on balanced excitatory and inhibitory receptor densities.
- Neuromodulatory receptors have subtler effects on brain rhythms.
- Dynamic causal modelling connects receptor types to specific oscillatory frequencies.

## Abstract

Stoof et al. investigate why distinct brain regions exhibit characteristic oscillatory frequencies, such as occipital alpha and frontal beta rhythms. Their work elegantly links openly available intracranial EEG spectra from 106 epilepsy patients to synaptic receptor densities from available autoradiography maps in three healthy donors. In the framework of dynamic causal modelling, they show that regional oscillations emerge from balanced combinations of excitatory (AMPAR, NMDAR) and inhibitory receptors (GABAR A or B), while neuromodulatory receptors exert subtler influences.

Synaptic tuning of brain rhythms. A network of neurons communicating via different synaptic receptors may give rise to brain oscillations at different frequencies in different brain regions. Left: schematic network of neurons communicating via different synaptic receptors. Right: brain oscillations at different frequencies in different brain regions coloured by the corresponding red, green blue mix of synaptic receptors. Images generated with biorender.com.