Theta oscillons in behaving rats

TL;DR

This paper investigates high-amplitude brain wave constituents called oscillons in behaving rats, revealing their similarities to theta waves and their transient, behavior-dependent properties, offering new insights into theta rhythm functions.

Contribution

It characterizes hippocampal and cortical oscillons as frequency-modulated waves with behavior-dependent properties, providing a new perspective on theta rhythm origins and functions.

Findings

Oscillons resemble traditional theta waves in frequency, amplitude, and bandwidth.

Oscillons exhibit transient, behavior-attuned properties.

Synchronization levels in neural networks are weak and modulated by locomotion.

Abstract

Recently discovered constituents of the brain waves -- the oscillons -- provide high-resolution representation of the extracellular field dynamics. Here we study the most robust, highest-amplitude oscillons that manifest in actively behaving rats and generally correspond to the traditional theta-waves. We show that the resemblances between theta-oscillons and the conventional theta-waves apply to the ballpark characteristics -- mean frequencies, amplitudes, and bandwidths. In addition, both hippocampal and cortical oscillons exhibit a number of intricate, behavior-attuned, transient properties that suggest a new vantage point for understanding the theta-rhythms' structure, origins and functions. We demonstrate that oscillons are frequency-modulated waves, with speed-controlled parameters, embedded into a noise background. We also use a basic model of neuronal synchronization to contextualize and to interpret the observed phenomena. In particular, we argue that the synchronicity level in physiological networks is fairly weak and modulated by the animal's locomotion.