The effect of right dlPFC cTBS on acute measures of anxiety, functional connectivity, and TMS-evoked BOLD responses

NIH RePORTER · MH · R01 · $762,440 · view on reporter.nih.gov ↗

Abstract

The right dorsolateral prefrontal cortex (dlPFC) is increasingly being targeted with transcranial magnetic stimulation (TMS) to reduce anxiety expression in anxiety disorders, depression, and posttraumatic stress disorder (PTSD). There seems to be clear mechanistic evidence that right dlPFC downregulation of amygdala activity should reduce fear and anxiety. Despite this mechanistic evidence, the primary approaches to treat anxiety with neuromodulation involve right dlPFC inhibition. Accordingly, there is a critical need to understand the mechanisms of action underlying neuromodulatory right dlPFC TMS protocols, yet there is not a standardized protocol to yield such evidence. Concurrent TMS/fMRI offers a unique translational perspective for understanding psychopathology. By experimentally stimulating a region of the brain and then directly measuring the activity evoked by this stimulation, it is possible to causally determine the downstream targets of this region, facilitating the development of novel TMS treatments for disorders like PTSD and anxiety. The objective of the current project is to develop a protocol using interleaved TMS/fMRI that can assess the effect of neuromodulatory (potentially therapeutic) TMS protocols on neural and behavioral measures related to anxiety expression. As a proof of concept, we will determine the effect of continuous theta burst stimulation (cTBS) to the right dlPFC on TMS-evoked fMRI responses in anxious subjects. Our central hypothesis is that cTBS of the right dlPFC will drive down activity throughout its downstream targets, resulting in reduced anxiety and greater TMS-evoked deactivations in these downstream circuits. Accordingly, our approach will be to measure anxious arousal and TMS-evoked BOLD responses before and immediately after 1800 pulses of cTBS, or sham stimulation in 140 high anxious individuals using a within-subjects crossover design. Our primary outcome will be TMS-evoked BOLD responses in a network of downstream

Key facts

NIH application ID
11222995
Project number
1R01MH138375-01A1
Recipient
UNIVERSITY OF PENNSYLVANIA
Principal Investigator
Lily A Brown; nicholas LEE balderston
Activity code
R01
Funding institute
MH
Fiscal year
2026
Award amount
$762,440
Award type
1
Project period
2026-04-01T00:00:00 → 2031-01-31T00:00:00