THE GLUTAMATE ANTAGONIST RILUZOLE SUPPRESSES INTRACORTICAL FACILITATION

The effect of the glutamate antagonist riluzole on excitatory and inhi bitory phenomena in the human motor system was studied by transcranial magnetic stimulation (TMS) and peripheral electrical nerve stimulatio n. The motor threshold, the intracortical inhibition and intracortical facilitation as assessed by paired TMS, the cortical and peripheral s ilent periods, F wave amplitudes and F wave latencies were measured. R iluzole suppressed the intracortical facilitation whereas other parame ters remained unchanged, indicating that the neurotransmitter glutamat e is mainly involved in facilitatory mechanisms in the motor system.