Alpha rhythm functions as a pacemaker for resting-state network excitability.

The alpha rhythm is a distinctive feature of the awake resting-state of the human brain. Recent evidence suggests that alpha plays an active role in information processing. However, the relationship between alpha oscillations and underlying neuronal dynamics remains poorly understood. To address this question, we investigate collective neural activity during resting wake and NREM sleep, a physiologic state with marginal presence of alpha rhythm. We show that, during resting wake, alpha oscillations drive alternation of attenuation and amplification bouts in neural activity. Our analysis indicates that inhibition is activated in pulses that last a single alpha cycle and gradually suppress neural activity, while excitation is successively enhanced over the timescales of a few alpha cycles to amplify neural activity. Furthermore, we show that long-term, intermittent fluctuations in alpha amplitude ---known as the "waxing and waning" phenomenon--- are associated with an attenuation-amplification mechanism. Importantly, we do not observe such dynamics during NREM sleep. These findings suggest that the alpha rhythm functions as a "pacemaker" for the alternation of inhibition and excitation.