Changes in electroencephalogram and cerebral blood flow during frequent yawns in human

Abstract

Our previous studies showed that frequent yawns can be evoked by microinjection of L-glutamate into the paraventricular nucleus (PVN) in an anesthetized, spontaneously breathing rat. The yawning response was characterized by an arousal shift in the ECoG to lower voltage and faster rhythms. We focused the present study upon frequent yawns in human. Yawns occurred once a few minutes for more than 5 minutes in this study. We monitored electroencephalogram (EEG) and cerebral blood flow (CBF) using near-infrared spectroscopy (NIRS). We found a shift in the EEG to lower voltage and faster rhythms and an increase of CBF in ventromedial prefrontal cortex (PFC) during and immediately after yawning responses. These results suggest that the activation of ventromedial PFC may be associated with an arousal/yawning response in human. [J Physiol Sci. 2006;56 Suppl:S74]