Summary: A new study uncovered the first direct evidence that deep brain stimulation (DBS) physically remodels white matter pathways and rewires large-scale neural networks. The study addresses a historic diagnostic blind spot by proving that “brain pacemakers” do not merely shift short-term electrical activity.
Instead, by delivering high-frequency impulses to subcortical structures, the therapy drives structural plasticity, increasing cellular myelination to repair the disrupted mood-regulation circuits that trap patients in severe, treatment-resistant depression.
Key Facts
- The Black Box of Neuromodulation: While deep brain stimulation is FDA-approved to treat disorders like Parkinson’s disease, epilepsy, and OCD, and has shown sustained clinical benefits for patients with severe, treatment-resistant depression, its long-term biological mechanisms have remained poorly understood. Clinicians knew the electrical impulses worked, but how they sustained long-term psychiatric recovery remained a mystery.
- Isolating the Structural Blueprint: Co-senior authors Dr. Peter Rudebeck and Dr. Helen Mayberg targeted white matter pathways adjacent to the subcallosal anterior cingulate cortex (SCC)—a brain region known to act as an effective clinical target for depression relief. By utilizing a non-human primate model, the team successfully isolated the direct biological effects of stimulation without any confounding variables from underlying disease states.
- The White Matter Metamorphosis: The study revealed that SCC-DBS selectively increased fractional anisotropy—a definitive imaging marker for white matter structural integrity and organization—directly within the cingulum bundle, a major neural highway implicated in human mood regulation.
- Cellular Upgrades in Myelination: At the microscopic level, the high-frequency stimulation triggered a dramatic spike in both the total number of myelinated oligodendrocytes (the vital support cells responsible for running neural signaling) and the overall degree of myelination along the pathway. This increase in myelin acts as an absolute structural upgrade, accelerating how effectively electrical signals travel across brain circuits.
- Dismantling the Default Mode Network: Beyond localized structural healing, Mount Sinai observed widespread, systemic changes in functional connectivity across large-scale neural networks. Most notably, the treatment altered communication across the default mode network, the specific interconnected brain regions heavily implicated in depression, severe anxiety, and toxic cognitive rumination.
- The Horizon of Non-Surgical Plasticity: Funded in part by the National Institutes of Health (NIH) BRAIN initiative, the team at the Nash Family Center for Advanced Circuit Therapeutics is already transitioning this research to human clinical trials. Unveiling that DBS drives structural plasticity in white matter allows scientists to optimize future electrode stimulation approaches and potentially develop entirely new, non-surgical therapies designed to remodel white matter paths.
Source: Mount Sinai Hospital
Researchers from the Icahn School of Medicine at Mount Sinai have uncovered the first direct evidence that deep brain stimulation (DBS) can remodel white matter pathways in the brain and alter communication across large-scale neural networks, revealing a previously unrecognized mechanism that may explain how the therapy helps patients recover from severe depression.
The study, published June 1in Nature Neuroscience, provides critical insight into the biological basis of DBS, an emerging therapy for treatment-resistant depression and other neuropsychiatric disorders.
Deep brain stimulation, approved by the U.S. Food and Drug Administration to treat essential tremor, Parkinson’s disease, epilepsy, and obsessive-compulsive disorder, is a neurosurgical procedure involving placement of a neurostimulator (sometimes referred to as a “brain pacemaker”), which sends high-frequency electrical impulses through implanted electrodes deep in the brain to specific areas responsible for the symptoms of each disorder.
Although DBS has shown sustained clinical benefit for many patients with severe depression who do not respond to medications, psychotherapy, and electroconvulsive therapy, the mechanisms underlying its therapeutic effects have remained poorly understood.
“What is exciting about our findings is that they change how we think about deep brain stimulation,” said Peter Rudebeck, PhD, Professor of Neuroscience, and Psychiatry, at the Icahn School of Medicine at Mount Sinai and co-senior author of the paper. “For the first time, we show that DBS does not simply alter electrical activity in the brain in the short term—it can actually remodel white matter structure, essentially rewiring brain circuits associated with depression.”
In the study, investigators delivered DBS to white matter pathways adjacent to the subcallosal anterior cingulate cortex (SCC), a brain region previously identified as an effective target for treating depression in humans.
White matter is a type of tissue found below the surface or cortex of the brain and consists mainly of bundles of axons, which are extensions of brain cells that transmit electrical signals. Using a non-human primate model, researchers were able to isolate the direct biological effects of stimulation without the confounding influence of underlying disease.
The team found that SCC-DBS selectively increased fractional anisotropy—a marker associated with white matter integrity and organization—within the cingulum bundle, one of the major white matter tracts implicated in mood regulation. At the cellular level, DBS increased both the number of myelinated oligodendrocytes and the degree of myelination within the pathway.
Oligodendrocytes are the support cells in the white matter of the brain that help to promote the propagation of neural signals; an increase in these cells suggests that stimulation promotes structural remodeling of brain circuitry.
Researchers also observed widespread changes in functional connectivity across the brain, particularly involving the default mode network, a network of areas strongly implicated in depression and rumination.
“Previously, it was not clear how deep brain stimulation affected brain structure and function,” said Helen Mayberg, MD, Professor of Neurology, Neurosurgery, Psychiatry, and Neuroscience at the Icahn School of Medicine and co-senior author of the paper.
“This study addresses a major gap in our understanding and points to an unappreciated mechanism contributing to sustained long-term recovery, something we have observed in our DBS depression clinical research over many years and an important focus of our current National Institutes of Health BRAIN initiative-funded studies.”
The findings may have important implications for improving DBS therapies and developing entirely new treatment strategies aimed at promoting white matter remodeling.
“Now that we know DBS can drive structural plasticity in white matter, we can begin thinking about how to optimize stimulation approaches and potentially develop novel therapies that target these mechanisms through nonsurgical means,” said Dr. Mayberg.
The study also opens broader questions about whether similar mechanisms may contribute to recovery in other psychiatric and neurological disorders treated with DBS.
Dr. Mayberg and her team at the Nash Family Center for Advanced Circuit Therapeutics at Mount Sinai are now investigating whether the same white matter remodeling effects occur in human patients undergoing DBS for depression. Future work will also examine how DBS alters patterns of activity in individual neurons across brain networks.
“Understanding how brain circuits physically and functionally change in response to stimulation could hasten development of next-generation therapies for psychiatric disorders,” said Brian Russ, PhD, co-senior study author and Research Scientist at the Nathan Kline Institute for Psychiatric Research, a facility of the New York State Office of Mental Health.
Key Questions Answered:
A: Because changing electricity is temporary, but changing white matter structure is a permanent architectural upgrade. For years, scientists thought DBS worked like an aspirin, temporarily altering electrical currents while active. Mount Sinai’s breakthrough proves for the first time that DBS actually acts like a team of biological contractors, physically rebuilding, insulating, and rewiring the broken white matter connections that cause depression in the first place.
A: Oligodendrocytes are the unsung support cells of the brain’s white matter that wrap nerve fibers in a protective coating called myelin, which helps electrical signals travel smoothly and quickly. In severe depression, these communication paths are often compromised. The study showed that DBS actively multiplies these cells and boosts myelination, creating a stronger, highly insulated highway that lets mood-regulating networks talk to each other without interruption.
A: By revealing the exact cellular target that needs to be triggered. Now that Dr. Helen Mayberg and her team know that driving structural plasticity in white matter is the secret key to long-term recovery, they don’t have to guess what mechanism to target. Scientists can now use this exact blueprint to design next-generation, non-invasive therapies, like targeted magnetic or electrical fields, to stimulate white matter remodeling without requiring surgery at all.
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 and depression research news
Author: Elizabeth Dowling
Source: Mount Sinai Hospital
Contact: Elizabeth Dowling – Mount Sinai Hospital
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Deep brain stimulation induces white matter remodeling and functional changes to brain-wide networks” by Satoka H. Fujimoto, Atsushi Fujimoto, Catherine Elorette, Adela Seltzer, Emma Andraka, Keondre Herbert, Gaurav Verma, William G. M. Janssen, Lazar Fleysher, Davide Folloni, Ki Sueng Choi, Brian E. Russ, Helen S. Mayberg & Peter H. Rudebeck. Nature Neuroscience
DOI:10.1038/s41593-026-02301-4
Abstract
Deep brain stimulation induces white matter remodeling and functional changes to brain-wide networks
Deep brain stimulation (DBS) is an emerging therapy for treatment-resistant neurological and psychiatric disorders. Despite this, little is known about the anatomical and functional mechanisms that underlie this therapy.
We targeted DBS to white matter adjacent to the subcallosal anterior cingulate cortex (SCC-DBS) in macaques, modeling the approach proven effective for depression in humans. SCC-DBS caused a selective increase in fractional anisotropy, linked to white matter microstructure, in the cingulum bundle.
At the cellular level, this was associated with an increase in both myelinated oligodendrocytes and the degree of myelination in the mid-cingulum bundle. SCC-DBS also altered brain-wide functional connectivity, changing interactions between the SCC and multiple brain networks, most notably the default mode network that has been implicated in depression.
Overall, our data indicate that white matter remodeling as well as selective changes in multiple brain networks may contribute to DBS’s therapeutic efficacy.
