On November 26, Yonsei Department of Biotechnology Professor Cheong Eun-ji and his research team had their article published in the prestigious scientific journal PNAS (IF 9.737). The article, which addresses a fundamental issue in sleep rhythm generation, is entitled “Sleep spindles are generated in the absence of T-type calcium channel-mediated low-threshold burst firing of thalamocortical neurons.” Focusing on the generation of sleep spindles, or bursts of neural oscillation which are defining characteristics of stage 2 sleep, the research shows that the previously accepted theory of the key component for sleep spindles—low-threshold burst firing mediated by T-type calcium channels in thalamocortical neurons—is incorrect. Furthermore, the authors suggest that tonic firing may play an important role in the generation of sleep spindles. According to the authors: “This study advances the knowledge of sleep and vigilance control to another level of understanding.”