The Contribution of Endogenous Modulatory Systems to TMS- and tDCS-Induced Analgesia: Evidence from PET Studies
Table 4
A summary of the main findings of the studies investigating the effects of TMS on the serotonergic system.
Serotonergic system
Study
Design
Population (n)
Intervention
Result
Kuo et al., 2016
Crossover randomized double-blind placebo-controlled study
Healthy volunteers.
Four sessions of active tDCS of M1, after intake of placebo, dextromethorphan or citalopram
Chronic administration of citalopram prolonged and enhanced the LTP driven by anodal stimulation. Furthermore, it converted the LTD related to cathodal stimulation into facilitation. Both effects were reverted by dextromethorphan administration.