Posttraumatic stress disorder (PTSD) is characterized not only by strongly encoded traumatic memories but also by disruptions in the coordination of entire brain networks. New research shows that treatment with psychedelic drugs causes a massive reorganization of brain network dynamics caused by remodeling of myelin, the nerve insulating layer. Discoveries from new research in biological psychiatryA paper published by Elsevier shows that enhancing myelination may be a viable strategy to enhance or maintain the therapeutic effects of psychedelic-assisted treatments for PTSD and related disorders.
Psilocybin and 3,4-methylenedioxymethamphetamine (MDMA) have rapid clinical effects in patients with PTSD. However, circuit-level stabilization is required to realize lasting benefits. Because the underlying cellular mechanisms remain incompletely understood, this study identifies myelin as the missing link between short-term psychedelic experiences and the long-term maintenance of healthier neural network dynamics. This study shows that activity-dependent oligodendrogenesis and myelin remodeling can orchestrate the untimely and sustained responses to threat observed in PTSD by synchronizing and harmonizing the rhythms of brain circuits.
John Crystal, MD, Editor biological psychiatry“The focus of psychedelic and MDMA research has been the effects of these drugs on neurons and neuroplasticity. This research has largely ignored the potentially important role of other cell types in the neurobiology of therapeutic effects. Another group of oligodendrocytes is involved in immune and inflammatory functions in the brain. ”
The researchers used a rat model of situational fear conditioning and repeatedly administered low doses of psilocybin or MDMA. We then quantified anxiety-like and exploratory behaviors and assessed spatial learning and memory.
The results showed a reduction in anxiety-like behavior, a change that was accompanied by changes in oligodendrocyte biology and multiomic (genetic) signatures toward myelin remodeling in the dentate gyrus (part of the hippocampus, the brain’s memory center).
To test whether myelin integrity is simply associated with, or actually required for, behavioral changes, we combined drug interventions with models that damage (demyelination) or chemically strengthen (promyelination) brain insulation to see how these changes influence recovery. ”
Dr. Mehmet Bostancıklıoğlu, Principal Investigator, Department of Physiology, Faculty of Medicine, Gaziantep University, Gaziantep, Türkiye
Using high-powered microscopy and genetic analysis, researchers confirmed that both psilocybin and MDMA cause physical myelin repair. Additionally, blockade of the serotonin receptor 5-HT2A prevented both behavioral and myelin-related effects. When the researchers used another drug (anisomycin) to block the formation of fear memories, anxiety decreased, but myelin remained unrepaired. This suggests that although memory can be suppressed, structural support of myelin is required for biological recovery.
“Taken together, this moves oligodendrocytes and adaptive myelination from a ‘background correlate’ to a gate that can be mechanistically tested for the durability of psychedelic-related circuit changes,” Dr. Bostančukluoğlu points out.
“The involvement of oligodendrocytes in the therapeutic effects of hallucinogens and MDMA is important for many functions in the brain, including myelination, glutamate homeostasis, and neuroinflammation. The dependence of the therapeutic effects of these drugs in animals may suggest that myelin damage may impair their effectiveness,” added Dr. Crystal. “Overall, these data suggest that psychedelics and MDMA, similar to selective serotonin reuptake inhibitors (SSRIs) and ketamine, may promote recovery from stress-related myelin damage and contribute to clinical recovery.”
The study also found that psilocybin and MDMA reduced astrocyte reactivity, which can cause inflammation.
Researchers note that enhancing myelination is not a replacement for psychological therapy. Rather, it may support the integration and maintenance of healthier network communications as the brain moves from destabilization to reintegration after an acute psychedelic session.
“We often talk about psychedelic drugs as ‘opening a window’ on plasticity in the brain,” Dr. Bostančkuroglu said. “Recent studies show that these drugs rapidly loosen clotted network patterns, leaving behind a subacute phase in which circuits can be reshaped by experience.” “What we show here is that myelin-producing cells may be an underappreciated part of the story, helping to transform temporary windows into longer-lasting circuits.” At least in the fear-based rat model that will change. ”
sauce:
Reference magazines:
Bostanjukriol, M., others. (2026). MDMA and psilocybin control oligodendrocyte lineage cell number and anxiety-like behavior in a rat fear model. biological psychiatry. DOI: 10.1016/j.biopsych.2026.01.016. https://www.biologicalpsychiatryjournal.com/article/S0006-3223(26)00052-1/fulltext
