GABAB-receptor (GABABR) mediated inhibition is important in regulating neuronal excitability. The paired-pulse transcranial magnetic stimulation (TMS) protocol of @entity1162 ( @entity1162 ) likely reflects this GABABergic inhibition. However, this view is based on indirect evidence from electromyographic (EMG) studies. Here we combined paired-pulse TMS with simultaneous electroencephalography (paired-pulse TMS-EEG) and pharmacology to directly investigate mechanisms of @entity1162 at the cortical level. We tested the effects of a conditioning stimulus (CS100) applied 100ms prior to a @entity1062 ( @entity1062 ) over primary motor cortex on @entity1062 -evoked EEG-potentials (TEPs). Healthy subjects were given a single oral dose of baclofen, a GABABR agonist, or diazepam, a positive modulator at GABAARs, in a placebo-controlled, pseudo-randomized double-blinded crossover study. @entity1162 was quantified as the difference between paired-pulse TEPs (corrected for long-lasting EEG responses by the conditioning pulse) minus single-pulse TEPs. @entity1162 at baseline (i.e. pre-drug intake) was characterized by decreased @entity4667 , N45, N100 and P180 and increased @entity19176 TEP components. Baclofen resulted in a trend towards the enhancement of @entity1162 of the N45 and N100, and significantly enhanced @entity1162 of the P180. In contrast, diazepam consistently suppressed @entity1162 of late potentials (i.e. N100, P180), without having an effect on @entity1162 of earlier (i.e. @entity4667 , N45 and @entity19176 ) potentials. These findings demonstrate for the first time directly at the system level of the @entity1 cortex that GABABR-mediated cortical inhibition contributes to @entity1162 , while GABAAR-mediated inhibition occludes @entity1162 . Paired-pulse TMS-EEG allows investigating cortical GABABR-mediated inhibition more directly and specifically than hitherto possible, and may thus inform on @entity854 caused by disordered inhibition, e.g. in @entity1 with @entity161 or @entity302 .

Characterization of GABAB-receptor mediated neurotransmission in the XXXX cortex by paired-pulse TMS-EEG.

@entity1 :: ('9606', 'Species') :: ['human', 'patients'] @entity19176 :: ('84959', 'Gene') :: ['P70'] @entity854 :: ('MESH:D018376', 'Disease') :: ['network abnormalities'] @entity161 :: ('MESH:D012559', 'Disease') :: ['schizophrenia'] @entity302 :: ('MESH:D004827', 'Disease') :: ['epilepsy'] @entity1062 :: ('MESH:D013736', 'Disease') :: ['test stimulus', 'TS'] @entity1162 :: ('MESH:D008133', 'Disease') :: ['long-interval intracortical inhibition', 'LICI'] @entity4667 :: ('11076', 'Gene') :: ['P25']
@entity1 :: (9606,Species) :: ['human']
