[New Paper] Cortico-basal-ganglia network for response inhibition

Watanabe, T., Hanajima, R., Shirota, Y., Tsutsumi, R., Shimizu, T., Hayashi, T., et al. (2015). Effects of rTMS of Pre-Supplementary Motor Area on Fronto Basal Ganglia Network Activity during Stop-Signal Task. The Journal of Neuroscience: 35(12), 4813–4823. 

Response inhibition is one of the key cognitive functions that enable humans to realise their own intentions, and is considered to be supported by fronto-basal-ganglia network. However, causal relationship inside the network has remained unclear.

Here, combining relatively long-lasting types of repetitive transcranial magnetic stimulation (rTMS) with functional magnetic resonance imaging (fMRI), we revealed causal effects of presupplementary motor area (PreSMA) on the network. Using well-established stop-signal task, we found that excitatory and inhibitory rTMS over PreSMA induced significant activity changes in a neural pathway consisting of PreSMA, striatum (STR) and globus pallidus pars interna (GPi). Furthermore, this effect on PreSMA–STR–GPi network activity was highly predictive of behavioral modulations. Interestingly, such causal effects were not seen in right inferior prefrontal cortex or subthalamic nucleus, both of which have been considered to mainly constitute neural mechanisms for response inhibition.

The work will not only demonstrate a causal relationship from PreSMA to basal ganglia during response inhibition, but also add direct evidence for the notion that the fronto-basal-ganglia network for response inhibition comprises multiple top-down regulation pathways in humans.