![\"This](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/04\/brain-stimulation-memory-neuroscience.jpg\")
Researchers demonstrated that personalizing the stimulation site based on unique brain connectivity is the key to noninvasive deep-brain modulation. Credit: Neuroscience News<\/p>\nSummary: For years, the hippocampus\u2014the brain\u2019s engine for memory and emotion\u2014was considered \u201cout of reach\u201d for noninvasive treatments because it sits so deep in the skull. To influence it, doctors usually needed surgery or drugs. However, neuroscientists have achieved a world-first: using Transcranial Magnetic Stimulation (TMS) on the brain\u2019s surface to precisely modulate the deep hippocampus.<\/p>\n
The study proves that by mapping a patient\u2019s unique brain \u201chighways\u201d (connectivity) via fMRI, doctors can find a specific spot on the cortex that acts as a remote control for the deep brain.<\/p>\n
Key Facts<\/p>\n
The \u201cRemote Control\u201d Effect: TMS uses magnetic pulses on the scalp. The researchers found that stimulating specific areas of the outer cortex can \u201csend\u201d a signal deep into the hippocampus if those two areas are functionally connected.Personalization is Power: The study found that stimulation only worked robustly when the site was tailored to the individual\u2019s unique brain map. When a \u201cone-size-fits-all\u201d spot was used, the deep brain barely responded.Rare Clinical Proof: The team verified their results using eight neurosurgical patients who already had internal electrodes. This allowed them to \u201czap\u201d from the outside and immediately \u201clisten\u201d from the inside.Large-Scale Validation: They confirmed the theory in 79 healthy participants, showing that the stronger the \u201chighway\u201d (connectivity) between the surface spot and the deep spot, the better the treatment worked.Clinical Future: This paves the way for non-surgical treatments for Alzheimer\u2019s, depression, PTSD, and anxiety by repairing deep-brain circuits without a single incision.<\/p>\n
Source: University of Iowa<\/p>\n
Neuroscientists at\u00a0University\u00a0of Iowa Health Care have\u00a0demonstrated\u00a0for the first time that\u00a0noninvasive\u00a0brain stimulation can alter the activity of a critical deep brain region involved in emotion and memory. <\/p>\n
Moreover, the study shows that personalizing the stimulation site using a patient\u2019s unique brain connectivity pathway can increase the neuromodulation effect.\u00a0<\/p>\n
Researchers demonstrated that personalizing the stimulation site based on unique brain connectivity is the key to noninvasive deep-brain modulation. Credit: Neuroscience News<\/p>\n
The study, published recently online in\u00a0Nature Communications,\u00a0used innovative, concurrent brain stimulation and recording techniques in people to provide direct human evidence that\u00a0noninvasive\u00a0transcranial magnetic stimulation (TMS) can reliably engage and modulate activity in the hippocampus.\u00a0<\/p>\n
The hippocampus is a deep brain region that plays a critical role in multiple brain functions, such as memory and emotion. Problems with hippocampal function have been implicated in several neurological and neuropsychiatric conditions including Alzheimer\u2019s disease, depression, anxiety, and post-traumatic stress disorder (PTSD).\u00a0\u00a0<\/p>\n
\u201cThe idea of manipulating neural activity in the hippocampus to help treat these types of conditions is appealing, but because the hippocampus lies so deep inside the brain, the challenge is how to engage these brain cells without using invasive implants or drugs that are not precisely targeted,\u201d says senior study author Jing Jiang, PhD, UI assistant professor of pediatrics.<\/p>\n
\u201cThese first-of-their-kind findings establish a foundation for a safer,\u00a0noninvasive, and personalized neuromodulation approach to target hippocampus-dependent functions and could potentially lead to new understanding of and new ways to treat these conditions.\u201d\u00a0\u00a0<\/p>\n
Personalizing\u00a0noninvasive\u00a0brain stimulation\u00a0<\/p>\n
Jiang and her colleagues studied eight neurosurgical patients who had electrodes implants in their hippocampus. This rare clinical situation allowed the researchers to combine noninvasive brain stimulation using TMS with concurrent measurement of immediate activity changes in the hippocampus using the intracranial electroencephalography (iEEG) electrodes.\u00a0\u00a0<\/p>\n
Rather than stimulating the same brain location in every individual, the researchers were able to tailor the stimulation site based on each person\u2019s unique brain connectivity in\u00a0four\u00a0patients.<\/p>\n
Resting-state\u00a0functional magnetic resonance imaging\u00a0(fMRI)\u00a0was used to trace the unique hippocampal connectivity map in each person\u2019s brain.\u00a0This information helped\u00a0identify\u00a0individualized TMS-accessible sites\u00a0in the cortex\u00a0that were most strongly connected to the hippocampus.\u00a0\u00a0\u00a0<\/p>\n
The researchers found that stimulating these individualized cortical sites, with either single-pulse TMS, or with repetitive TMS that is widely used in clinical treatment, preferentially elicited\u00a0evident\u00a0activity changes in the hippocampus.\u00a0In the other four patients whose stimulation sites were not personalized with patients\u2019 unique brain connectivity, no robust activity changes were\u00a0observed\u00a0in the hippocampus.\u00a0<\/p>\n
These findings were complemented with evidence from a\u00a0noninvasive\u00a0experiment that used TMS concurrently\u00a0with fMRI to measure activity changes in the hippocampus in 79 neurologically healthy participants.\u00a0\u00a0<\/p>\n
Although personalized sites were not stimulated in these individuals, the researchers still found compelling evidence to support this\u00a0strategy:\u00a0variations\u00a0in the strength of TMS-evoked hippocampal responses related to differences in functional connectivity pattern between the stimulation site and hippocampus.<\/p>\n
Specifically, the stronger the connectivity between the actual stimulation site and the hippocampus, or the closer the actual stimulation site to the\u00a0individualized\u00a0site, the stronger the TMS-evoked hippocampal responses were.\u00a0<\/p>\n
\u201cThis connectivity-informed strategy provides more precise targeting and modulation, which improves the effectiveness of stimulation effect, and may even help predict individual responses,\u201d says\u00a0Jiang who is also an assistant professor of psychiatry and a member of the Iowa Neuroscience Institute.<\/p>\n
\u201cPersonalizing brain stimulation site in this way represents a critical step toward more effective and reliable circuit-based neuromodulation treatments.\u201d\u00a0<\/p>\n
In addition to Jiang, the team included first author Zhuoran Li, and UI researchers Nicholas Trapp, Joel Bruss,\u00a0Xianqing\u00a0Li, Kang Wu, Ziyan Chen, Matthew Howard, and Aaron\u00a0Boes. Amit Etkin at Alto Neuroscience was also part of the team.\u00a0<\/p>\n
Funding: The research was funded in part by grants from the National Institute of Mental Health, the National Institute of Neurological Disorders and Stroke, both part of the National Institutes of Health; the Brain and Behavior Research Foundation; Magnus Medical, Inc.; and the Roy J. Carver Charitable Trust.<\/p>\n
Key Questions Answered:Q: If the hippocampus is \u201cdeep,\u201d how does a magnet on the outside reach it?<\/p>\n
A: It doesn\u2019t reach it directly. Think of it like a subway system. You can\u2019t reach the deepest station from the street, but if you find the right entrance (a connected spot on the cortex), the signal travels down the \u201ctracks\u201d (neural pathways) right to the platform (the hippocampus).<\/p>\n
Q: Why does it have to be \u201cpersonalized\u201d? Can\u2019t you just use the same spot for everyone?<\/p>\n
A: Everyone\u2019s \u201cbrain map\u201d is as unique as a fingerprint. In the study, when they used a generic spot, the \u201csignal\u201d got lost. It was only when they used fMRI to find each person\u2019s specific \u201centrance\u201d that the deep brain actually responded.<\/p>\n
Q: Does this mean we can \u201cdelete\u201d bad memories or \u201cfix\u201d depression instantly?<\/p>\n
A: Not quite. This is a tool for neuromodulation, which means \u201ctuning\u201d the brain\u2019s activity. For someone with PTSD or depression, the hippocampus might be hyperactive or sluggish. This tech allows doctors to \u201cre-tune\u201d those circuits back to a healthy frequency without surgery.<\/p>\n
Editorial Notes:This article was edited by a Neuroscience News editor.Journal paper reviewed in full.Additional context added by our staff.About this neurotech research news<\/p>\n
Author:\u00a0Jennifer Brown<\/a>
Source:\u00a0University of Iowa<\/a>
Contact:\u00a0Jennifer Brown \u2013 University of Iowa
Image:\u00a0The image is credited to Neuroscience News<\/p>\n