title: [GABA-B-associated neuropsychiatric disorders].
abstract: OBJECTIVE
  Disturbed GABA-B mediated inhibitory cortical processes are discussed to be involved both in schizophrenia as well as in chronic tinnitus. Transcranial magnetic stimulation (TMS) provides an intriguing in vivo method to investigate GABA-B associated aspects of cortical inhibition, thus allowing to detect disease-related cortical inhibitory processes.
  
  
  METHODS
  Parameters of cortical excitability were measured by TMS in drug-naive first-episode schizophrenic patients and in patients suffering from chronic tinnitus.
  
  
  RESULTS
  The cortical silent period as measured by TMS indicated a dysfunctional GABA-B mediated cortical inhibition in both groups of patients.
  
  
  CONCLUSIONS
  TMS offers new insights into the pathophysiology of neuropsychiatric disorders. Parameters of this technique point to changes in GABA-B associated inhibitory processes within thalamocortial circuits both in schizophrenia and chronic tinnitus. These data are in line with current models of disturbed thalamic gating in phantom perceptions like auditory hallucinations, chronic tinnitus and central pain.
authors.affiliation: Klinik für Psychiatrie und Psychotherapie der Universität Regensburg. peter.eichhammer@medbo.de
authors.forename: Peter
authors.initials: P
authors.lastname: Eichhammer
authors.forename: Berthold
authors.initials: B
authors.lastname: Langguth
authors.forename: Marc
authors.initials: M
authors.lastname: Zowe
authors.forename: Tobias
authors.initials: T
authors.lastname: Kleinjung
authors.forename: Peter
authors.initials: P
authors.lastname: Jacob
authors.forename: Philipp
authors.initials: P
authors.lastname: Sand
authors.forename: Göran
authors.initials: G
authors.lastname: Hajak
mesh_terms: D002540:Cerebral Cortex / Q000503:physiopathology*; D002908:Chronic Disease; D004292:Dominance, Cerebral / Q000502:physiology; D006801:Humans; D008280:Magnetics; D009044:Motor Cortex / Q000503:physiopathology; D009415:Nerve Net / Q000503:physiopathology; D009433:Neural Inhibition / Q000502:physiology*; D018080:Receptors, GABA-B / Q000502:physiology*; D012016:Reference Values; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D014012:Tinnitus / Q000503:physiopathology* / Q000523:psychology
chemical_list: D018080:Receptors, GABA-B