Assertion: yawning | /r/CreatedBy | nitric oxide
Facets:
value: in the brain
type: LOCATION
Source sentences:
text: The University of Cincinnati reports that Dr. George Bubenik of the University of Guelph in Ontario, Canada, believes that yawning is likely caused by chemical compounds or neurotransmitters in the brain, such as dopamine, nitric oxide or serotonin.