Klinische Neurophysiologie 2014; 45 - P102
DOI: 10.1055/s-0034-1371315

Impact of brain-derived neurotrophic factor (BDNF) gene polymorphism on cortical inhibition in schizophrenia

W Strube 1, T Bunse 1, T Wobrock 2, 3, S Witt 4, V Nieratschker 5, P Falkai 1, A Hasan 1
  • 1LMU, Psychiatrische Klinik, München, Deutschland
  • 2Universität Göttingen, Psychiatrie, Göttingen, Deutschland
  • 3Zentrum für Seelische Gesundheit, Psychiatrie, Groß-Umstadt, Deutschland
  • 4ZI Mannheim, Epidemiologie in der Psychiatrie, Mannheim, Deutschland
  • 5Universität Tübingen, Molekulare Psychiatrie, Tübingen, Deutschland

Introduction: Neuronal plasticity is a characteristic feature of the human central nervous system to dynamically respond to changes and demands inducing synaptical and neurochemical alterations. Using transcranial magnetic stimulation (TMS) in an intermittent theta-burst stimulation (iTBS) protocol, impaired cortical plasticity has been reported to be associated with a val/met gene-polymorphism in the brain-derived neurotrophic factor (BDNF) gene. Based on neuropathological findings and neuroimaging studies, impaired cortical plasticity has been described as a common, yet not fully understood phenomenon in patients with schizophrenia.

Objectives: The aim of the present study was to investigate the impact of the val/met BDNF gene-polymorphism on cortical plasticity in patients with schizophrenia.

Materials & Methods: Cortical plasticity was investigated using anodal and cathodal transcranial direct current stimulation (tDCS) applied to the primary motor cortex, thus inducing long-term potentiation (LTP) and long-term depression (LTD), respectively. LTP and LTD effects were probed by single and paired pulse TMS protocols before and after tDCS stimulation in a cross-sectional sample of schizophrenia patients (SZ) and healthy controls (HC). TMS in all participants was conducted using a standard 70 mm-TMS figure-of-eight magnetic coil connected to a MagPro X 100 magnetic stimulator. Analyses were focused on resting-motor threshold (RMT), 1mV motor-evoked potential (MEP), short-interval intracortical inhibition (SICI at 3 ms), intracortical facilitation (ICF at 12 ms) and cortical silent period (CSP at 120% RMT).

Results: The statistical analyses included n = 43 SZ and n = 44 HC participants (all numbers presented under reserve of further examination) thus resulting in the largest available sample to probe cortical plasticity parameters in BDNF-genotyped schizophrenia patients. Further results will be presented at the conference.

Conclusion: The findings will give new insights into the influence of plasticity-associated gene polymorphisms and the pathophysiology of schizophrenia.