Anesthesiology
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Ketamine is a noncompetitive N-methyl-D-aspartate antagonist and is known for unique electrophysiologic profiles in electroencephalography. However, the mechanisms of ketamine-induced unconsciousness are not clearly understood. The authors have investigated neuronal dynamics of ketamine-induced loss and return of consciousness and how multisensory processing is modified in the primate neocortex. ⋯ Ketamine generates unique intracortical dynamics during its altered states of consciousness, suggesting fundamentally different neuronal processes from propofol. The gradually shifting dynamics suggest a continuously conscious or dreaming state while unresponsive under ketamine until its deeper stage with the slow-delta oscillations. Somatosensory processing is preserved during ketamine anesthesia, but multisensory processing appears to be diminished under ketamine and through recovery.
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During myocardial ischemia, hypoxia-inducible factors are stabilized and provide protection from ischemia and reperfusion injury. Recent studies show that myocyte-specific hypoxia-inducible factor 2A promotes myocardial ischemia tolerance through induction of epidermal growth factor, amphiregulin. Here, the authors hypothesized that hypoxia-inducible factor 2A may enhance epidermal growth factor receptor 1 (ERBB1) expression in the myocardium that could interface between growth factors and its effect on providing tolerance to ischemia and reperfusion injury. ⋯ These findings suggest that hypoxia-inducible factor 2A promotes transcription-independent induction of ERBB1 protein and implicates epidermal growth factor signaling in protection from myocardial ischemia and reperfusion injury.