TMS-EEG in the Investigation of Excitation-Inhibition Imbalance in Psychosis and Cognition

Aims Transcranial Magnetic Stimulation (TMS) is an in-vivo, non-invasive, and safe method that probes neurophysiological properties associated with cortical glutamatergic (excitatory) GABAergic (inhibitory) neurotransmission. The combination of TMS Electroencephalography (EEG) allows us to measure TMS-evoked responses directly from brain activity it uniquely placed elucidate in-vivo Excitatory/Inhibitory processes. Schizophrenia has been Excitation/Inhibition (E/I) imbalance. Cognitive impairment, which almost ubiquitous in schizophrenia, linked the E/I abnormalities observed schizophrenia. Among TMS-EEG evoked potentials (TEPs), N100 thought reflect activation inhibitory GABA-B circuits attentional processes healthy individuals, attention deficit hyperactivity disorder (ADHD) depression. Our aim was investigate related generation after motor cortex stimulation its association measures patients schizophrenia controls. Methods TEPs were recorded following application 150 pulses at 90% resting threshold on two sites, i.e., left primary (M1) dorsolateral prefrontal (DLPFC) stable (n = 9) controls 9). Region Interest (ROI) analysis performed calculate regional average peak amplitude M1 DLPFC based previous literature. Attention assessed a Continuous Performance Task (CPT). Results We found significant negative correlation between CPT score patient group (rho -0.73, p 0.026). component did not correlate -0.034, 0.93), may suggest specificity Conclusion considered be influenced by cortico–striato–thalamo–cortical loops, greater producing larger amplitude. preliminary results GABA-B-ergic TEP represent inhibition beyond Overall, offers potential state dynamics imbalance cognition.