Neural oscillations are among the brain’s main strategies for coordinating activity across cells and circuits. Different frequency bands are often associated with different computational roles: slower rhythms can support long-range coordination, while faster rhythms such as gamma are thought to help structure local processing and information transfer. Yet an important question remains open: how can the same neural circuit generate both slow and fast oscillations, and why would this matter for communication?
In this study, led by colleagues at KIST and KAIST in South Korea, we addressed this question using a biologically plausible computational model of excitatory and inhibitory spiking neurons. They systematically varied the balance between inhibition and excitation and asked how this balance shapes the rhythms produced by the network. We found that slow beta-like and fast gamma-like oscillations can naturally coexist, but only within a specific range of inhibitory-to-excitatory synaptic strength. Outside this optimal regime, the network tends to fall back into simpler single-frequency dynamics.
This optimal inhibitory/excitatory regime was not only special because it produced richer oscillations. It also maximized the network’s ability to transmit information efficiently. In other words, the coexistence of slow and fast rhythms was not just a decorative feature of neural activity: it supported better communication. The network communicated most effectively when inhibition and excitation were balanced in a way that allowed multiple oscillatory timescales to interact.
The study therefore proposes a mechanistic link between E/I balance, multi-frequency oscillations, and neural communication. It suggests that the brain may tune inhibition not simply to stabilize activity, but also to create the right dynamical conditions for information transfer. Conversely, deviations from this optimal range may reduce communication efficiency and push circuits toward less flexible oscillatory states — a scenario relevant to neurological and psychiatric disorders in which E/I balance and oscillatory activity are disrupted.
A useful way to summarize the result is: the brain does not communicate best when activity is simply stronger or weaker, but when excitation and inhibition are tuned to produce the right rhythmical repertoire. Too little or too much inhibition impoverishes the dynamics; the right balance allows the circuit to combine slow coordination with fast communication.
This work highlights how computational neuroscience can reveal the “rules of tuning” behind brain rhythms. Rather than treating oscillations as mere by-products of neural activity, it shows how specific circuit parameters can shape the temporal structure of communication itself.
To know more:
- Kim, J. Y., Lee, S. W., Battaglia, D., Choi, J. H., & Yook, S.-H. (2025). Optimal inhibitory-to-excitatory ratio governs slow and fast oscillations for enhanced neural communication. Journal of Neuroscience, e0848252025. https://doi.org/10.1523/JNEUROSCI.0848-25.2025.