BACKGROUND: Several lines of evidence suggest that central cortical inhibitory mechanisms, especially associated with gamma-aminobutyric acid (GABA) neurotransmission, may play a role in the pathophysiology of major depression. Transcranial magnetic stimulation is a useful tool for investigating central cortical inhibitory mechanisms associated with GABAergic neurotransmission in psychiatric and neurological disorders. METHODS: By means of transcranial magnetic stimulation, different parameters of cortical excitability, including motor threshold, the cortical silent period, and intracortical inhibition/facilitation, were investigated in 20 medication-free depressed patients and 20 age- and gender-matched healthy volunteers. RESULTS: Silent period and intracortical inhibition were reduced in depressed patients, consistent with a reduced GABAergic tone. Moreover, patients showed a significant hemispheric asymmetry in motor threshold. CONCLUSIONS: This study provides evidence of reduced GABAergic tone and motor threshold asymmetry in patients with major depression.
BACKGROUND: Several lines of evidence suggest that central cortical inhibitory mechanisms, especially associated with gamma-aminobutyric acid (GABA) neurotransmission, may play a role in the pathophysiology of major depression. Transcranial magnetic stimulation is a useful tool for investigating central cortical inhibitory mechanisms associated with GABAergic neurotransmission in psychiatric and neurological disorders. METHODS: By means of transcranial magnetic stimulation, different parameters of cortical excitability, including motor threshold, the cortical silent period, and intracortical inhibition/facilitation, were investigated in 20 medication-free depressedpatients and 20 age- and gender-matched healthy volunteers. RESULTS: Silent period and intracortical inhibition were reduced in depressedpatients, consistent with a reduced GABAergic tone. Moreover, patients showed a significant hemispheric asymmetry in motor threshold. CONCLUSIONS: This study provides evidence of reduced GABAergic tone and motor threshold asymmetry in patients with major depression.
Authors: Dennis J L G Schutter; Antoin D de Weijer; Julia D I Meuwese; Barak Morgan; Jack van Honk Journal: Hum Brain Mapp Date: 2008-05 Impact factor: 5.038
Authors: Jeylan S Buyukdura; Shawn M McClintock; Paul E Croarkin Journal: Prog Neuropsychopharmacol Biol Psychiatry Date: 2010-10-31 Impact factor: 5.067
Authors: Irena Balzekas; Charles P Lewis; Julia Shekunov; John D Port; Gregory A Worrell; Hang Joon Jo; Paul E Croarkin Journal: Psychiatry Res Neuroimaging Date: 2018-05-31 Impact factor: 2.376
Authors: Jennifer I Lissemore; Apoorva Bhandari; Benoit H Mulsant; Eric J Lenze; Charles F Reynolds; Jordan F Karp; Tarek K Rajji; Yoshihiro Noda; Reza Zomorrodi; Etienne Sibille; Zafiris J Daskalakis; Daniel M Blumberger Journal: Neuropsychopharmacology Date: 2018-05-17 Impact factor: 7.853