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Home A New Type of Neuroplasticity Rewires the Brain After a Single Experience Comment Save Article Read Later Share Facebook Copied! Copy link Email Pocket Reddit Ycombinator Comment Comments Save Article Read Later Read Later neuroscience A New Type of Neuroplasticity Rewires the Brain After a Single Experience By Yasemin Saplakoglu April 24, 2026 “Neurons that fire together, wire together” is not the full story. A novel mechanism explains how the brain can learn across longer timescales. Comment Save Article Read Later Introduction Every experience we have changes our brain, the way a ceramicist reshapes a slab of clay. Every corner we turn, every conversation we have, every shudder we feel causes cascading effects: Chemicals are released, electricity surges, the connections between brain cells tighten, and our mental models update. The brain is “incredibly plastic, and it stays that way throughout the lifespan of a human,” said Christine Grienberger , a neuroscientist at Brandeis University. This plasticity, the quality of being easily reshaped, makes the brain really good at learning — a quintessential process that allows us to remember the plotline of a novel, navigate a new city, pick up a new language, and avoid touching a hot stove. But neuroscientists are still uncovering fundamental rules that describe how neuroplasticity reshapes brain connections. Recently, neuroscientists described a new form of neuroplasticity that might be helping the brain learn across a timescale of several seconds — long enough to capture the behavioral process of learning from a single experience. In two recent reviews, published in The Journal of Neuroscience and Nature Neuroscience , they describe “behavioral timescale synaptic plasticity,” or BTSP. This type of learning in the hippocampus, the brain’s memory hub, is caused by an electrical change that affects multiple neurons at once and unfolds across several seconds. Researchers suspect that it may help the brain learn in a single attempt. “It’s pretty clear that [BTSP is] a strong, powerful mechanism that can lead to immediate memory formation,” said Daniel Dombeck , a neuroscientist at Northwestern University who was not involved with the theory’s development. “It’s something that has been missing in the field for a long time.” By uncovering BTSP, neuroscientists have unraveled more of the story of how the brain changes with experience, bringing us closer to understanding how learning happens. “Neuroplasticity is … one of the last frontiers of the brain,” said Attila Losonczy , a neuroscientist at the University of Texas Southwestern Medical Center who studies BTSP. “If we understand this, I think we take a major step towards understanding how the brain works.” A Plastic Brain Today, neuroplasticity is taken as fact, but for much of the 150-year history of neuroscience, the adult brain was thought to be static. “The idea that the adult brain can change wasn’t actually widely accepted until very late [in] the history of modern neuroscience,” said Moheb Costandi , a trained neuroscientist and author of Neuroplasticity , a primer from MIT Press. “It was taken for granted that the adult human brain can’t change.” In 1928, Santiago Ramón y Cajal , the oft-cited founder of modern neuroscience, wrote that “in adult centers the nerve paths are something fixed, ended, immutable.” This idea would prevail well into the middle of the 20th century. We now know that the brain is constantly remolding itself, both functionally and structurally, across many scales — from the molecules that flow between neurons to the connections that stretch across the brain and beyond. The power of neuroplasticity is perhaps best demonstrated by case studies. One patient born without an olfactory bulb could smell because other parts of her brain remolded to serve as substitutes. Another patient had the entire left side of her brain removed as a baby; after her right side reorganized to take on the left’s former roles, today she has a functional life. When a stroke or an accident damages the brain, other neurons fill in to recover patients’ everyday functions such as speaking and walking. Neuroplasticity also drives everyday learning. This process is mainly thought to result from synaptic plasticity, or changes to the trillions of connections between neurons. And although the brain learns in various ways, one particular idea has dominated for more than 70 years. In 1949, Donald Hebb, a Canadian psychologist, articulated a theory of learning now known as Hebbian plasticity. According to this model, when neurons are activated within milliseconds of each other, the connection between them is physically strengthened , so that in the future they are more likely to fire together. Over time, they form a network that represents a concept or an experience. In other words, the more the networks in the brain are used, the stronger they get, an idea often summarized as “neurons that fire together, wire together.” But neuroscientists “always had a sneaking suspicion that Hebbian plasticity wasn’t quite right,” said Jeffrey Magee , a neuroscientist at Baylor College of Medicine. Or at least, it wasn’t the full story. It required an experience to be repeated multiple times to imprint the lesson on the brain — a framework that may explain how we learn a new city or language, but not how we learn from a single, highly charged experience, such as touching a hot stove. Even so, finding more explanatory mechanisms hasn’t been top of mind for neuroscientists. “It wasn’t a quest, like in particle physics for missing particles,” Losonczy said. Maybe there were a couple of gaps that needed to be filled, but most researchers assumed that the Hebbian framework would require only tweaks. Few were thinking that a fuller understanding of neuroplasticity might include a new mechanism. Mighty Trees In 2014, when Magee attached electrodes to rodents to record their neural activity, he wasn’t looking to challenge Hebbian plasticity. Magee, then at the Howard Hughes Medical Institute’s Janelia Research Campus, and his students Grienberger and Katie Bittner were looking to observe the behavior of neurons’ arms, called dendrites, in a living animal. These branches receive molecular signals at one end of a neuron and induce the cell to rapidly fire an electrical charge that ripples down the cell body, known as an action potential. This process ends with the neuron releasing its own batch of molecular signals, which latch onto the dendrites of the next neuron in the network, continuing the process. In recent decades, neuroscientists have come to a “slow realization that dendritic activity is super important for plasticity and for neuronal computations in general,” said Antoine Madar , a postdoc at the University of Chicago, who led the 2025 review of a Society for Neuroscience symposium on BTSP in The Journal of Neuroscience . There is a “zoo” of different events that take place at dendrites, he said. They can fire their own local or global electrical spikes. They can cover a larger or smaller area, and they can surge for longer or shorter periods of time. Neuroscientists have found that these events at dendrites can allow even single neurons to perform complex computations — meaning that dendrites are the reason why a single neuron can have the same amount of computational power as a deep artificial neural network . Still, there was much unknown about dendrites’ behavior. Neuroscientists have mainly characterized them in brain slices, where neurons are alive and can be activated but aren’t attached to a living animal. “We were trying to take that into the actual behaving animal, or the actual behaving brain,” Magee said. In 2014, they began to home in on the hippocampus, an especially plastic area of the brain where we form experiential memories. It’s also home to place cells, which fire when an animal moves through its environment . Each of these neurons learns to fire at s