N-Methyl D-Aspartate Receptor Antagonists Amplify Network Baseline Gamma Frequency (30-80 Hz) Oscillations: Noise and Signal

Abstract : AIMS Neuroscience Commentary on a special issue on : How do Gamma Frequency Oscillations and NMDA Receptors Contribute to Normal and Dysfunctional Cognitive Performance (Editor: Suresh D Muthukumaraswamy). N-methyl D-aspartate type glutamate receptor antagonists induce schizophreniform disorder symptoms accompanied with deficits in sensory-perception and cognition and with a dramatic and persistent amplification of electroencephalographic baseline gamma frequency (30-80 Hz) oscillations in cortical and subcortical regions, including the thalamus. This generalized network gamma noise might be the source of abnormal activities (e.g, during hallucinations) and disturb function-related synchronized oscillations. The corresponding gamma signal-to-noise ratio is proposed as a potential electrophysiological biomarker of network dysfunctions responsible for disturbances in sensorimotor and cognitive information processing associated with various mental disorders and brain illnesses. Testing theoretical and pathophysiological hypotheses is an appealing and effective basic-clinical translational way to understand how, in health and disease, our brain at work combines its various and miscellaneous molecular, synaptic, cellular and architectural complexities.