Alpha-frequency Transcranial Alternating Current Stimulation Attenuates Anxiety-induced Salience Network Hyperconnectivity

Poster Session A - Saturday, April 13, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

John Massa¹ (massa@psy.fsu.edu), Peter Kuan-Hao Cheng¹, Joshua Brown¹, Yijia Ma¹, Wen Li²; ¹Florida State University, ²UTHealth Houston

Anxiety and stress are common in society and have been linked to many neuropsychiatric illnesses. The understanding of anxiety has come to include network-level pathologies, with hyperfunctioning of the salience network (SN) being increasingly recognized. The SN, anchored on two cortical hubs (the dorsal anterior cingulate cortex/dACC and anterior insula/AI) and a subcortical hub (the amygdala), orients the brain to salient stimuli and coordinates defensive responses via other functional networks. Previous research from our lab has shown that network-level connectivity and anxious mood can be modulated by non-invasive brain stimulation, specifically alpha-frequency transcranial alternating current stimulation (alpha-tACS). In this study, we aimed to examine the efficacy of alpha-tACS in blunting heightened SN functioning in anxiety. Resting-state fMRI was recorded from 40 participants before and after anxiety induction, during which participants were randomly assigned to receive alpha-tACS or sham stimulation. Seed-based functional connectivity analysis revealed increases in SN connectivity (primarily between the amygdala and the dACC as well as the AI), confirming anxiety-related SN hyperfunctioning. Importantly, this effect was significantly modulated by group assignment, mainly present in the sham (vs. tACS) group. Therefore, alpha-tACS attenuated anxiety-induced SN hyperconnectivity, specifically between the amygdala and the cortical nodes. Taken together, these findings suggest that tACS may serve as an effective therapeutic that mitigates SN hyperfunctioning in anxiety by normalizing functional connectivity between the subcortical and cortical nodes.

Topic Area: EMOTION & SOCIAL: Emotion-cognition interactions