The following is a summary of “Probing prefrontal-sgACC connectivity using TMS-induced heart–brain coupling,” published in the April 2024 issue of Psychiatry by Dijkstra et al.
Transcranial magnetic stimulation (TMS) has been proposed to assess the engagement of frontal-vagal pathways without using fMRI-guided neuronavigation. Recent fmRI-guided TMS techniques aim to target specific brain regions linked to better antidepressant efficacy.
Researchers conducted a prospective study investigating the effects of TMS-induced heart-brain coupling (HBC) when targeting brain regions negatively connected to the subgenual anterior cingulate cortex (sgACC).
They reviewed 14 healthy participants who underwent neuro-navigated TMS targeting specific frontal and parietal brain areas connected positively, negatively, or neutrally to the sgACC, as determined by individual resting-state fMRI scans. TMS effects on HBC were compared across different target regions.
The results showed that most participants (12 of 14) showed maximal HBC at sites negatively connected to sgACC while targeting prefrontal areas. HBC power was significantly higher in left frontal (d = 0.68) and left parietal (d = 0.75) targets negatively connected to sgACC compared to neutrally connected targets. However, the strength of negative connectivity did not influence this effect. In contrast, HBC power correlated with sgACC connectivity strength in right frontal (r = 0.56) and right parietal (r = 0.72) targets negatively connected to sgACC.
Investigators concluded that fMRI-guided TMS could predictably modulate heart rate using HBC, suggesting that HBC could help efficiently identify individualized TMS targets targeting prefrontal-sgACC connectivity.
Source: nature.com/articles/s44220-024-00248-8
