Causally probing the role of the hippocampus in fear discrimination: a precision functional mapping–guided, transcranial magnetic stimulation study in participants with posttraumatic stress symptoms

Ryan D. Webler, Cristian Morales, Samuel E. Cooper, Mo Chen, Christopher O. Hunt, Sierra Hennessy, Lancy Cao, Carol Lam, Allen Chiu, Cash Differding, Erin Todd, Timothy J. Hendrickson, Desmond J. Oathes, Alik S. Widge, Robert J.M. Hermosillo, Steven M. Nelson, Damien A. Fair, Shmuel M. Lissek, Ziad Nahas
January 2024
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Abstract

BackgroundFear overgeneralization is a promising pathogenic mechanism of clinical anxiety. A dominant model posits that hippocampal pattern separation failures drive overgeneralization. Hippocampal network–targeted transcranial magnetic stimulation (HNT-TMS) has been shown to strengthen hippocampal-dependent learning/memory processes. However, no study has examined whether HNT-TMS can alter fear learning/memory.MethodsContinuous theta burst stimulation was delivered to individualized left posterior parietal stimulation sites derived via seed-based connectivity, precision functional mapping, and electric field modeling methods. A vertex control site was also stimulated in a within-participant, randomized controlled design. Continuous theta burst stimulation was delivered prior to 2 visual discrimination tasks (1 fear based, 1 neutral). Multilevel models were used to model and test data …

Type
Journal article
Publication
Biological Psychiatry Global Open Science
Cristian Morales
Cristian Morales
Principal Investigator

Cristian Morales Carrasco is an electrical engineer with an MSc in Electrical Engineering and a PhD in Biomedical Engineering. His research focuses on functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS).