{"id":88283,"date":"2025-07-24T09:28:11","date_gmt":"2025-07-24T09:28:11","guid":{"rendered":"https:\/\/www.europesays.com\/us\/88283\/"},"modified":"2025-07-24T09:28:11","modified_gmt":"2025-07-24T09:28:11","slug":"your-brain-maps-the-same-path-differently-every-time","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/88283\/","title":{"rendered":"Your Brain Maps the Same Path Differently Every Time"},"content":{"rendered":"<p><strong>Summary: <\/strong>New research shows that our brain\u2019s internal map rewrites itself every time we navigate a familiar environment. Even when mice experienced identical virtual mazes with controlled sensory input, their hippocampal neurons activated in different patterns on each run.<\/p>\n<p>This suggests spatial memories are dynamic, evolving rather than fixed, and may encode the passage of time. The findings offer insights into how memory works \u2014 and how aging might affect it.<\/p>\n<p><strong>Key Facts:<\/strong><\/p>\n<ul class=\"wp-block-list\">\n<li><strong>Dynamic Maps:<\/strong> The hippocampus updates spatial memories even in identical settings.<\/li>\n<li><strong>Neural Drift:<\/strong> Different neurons encode the same experience on each repetition.<\/li>\n<li><strong>Aging Link:<\/strong> Highly excitable neurons maintain stable memories longer, which declines with age.<\/li>\n<\/ul>\n<p><strong>Source: <\/strong>Northwestern University<\/p>\n<p><strong>In a new study, Northwestern University neurobiologists found the brain\u2019s internal GPS changes each time we navigate a familiar, static environment.<\/strong><\/p>\n<p>This means that if someone walks the same path every day \u2014 and the path and surrounding conditions remain identical \u2014 each walk still activates different \u201cmap-making\u201d brain cells, or neurons.<\/p>\n<p>Not only does this discovery shed light on the fundamental mystery of how the brain processes and stores spatial memories, but it also could have profound implications for scientists\u2019 understanding of memory, learning and even aging.<\/p>\n<p>  <img fetchpriority=\"high\" decoding=\"async\" width=\"1200\" height=\"799\" src=\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/07\/memory-mapping-neurosicnce.jpg\" alt=\"This shows the brain as a maze.\"  \/> The most excitable neurons, which were more easily activated, maintained more stable spatial memories throughout multiple runs through the virtual maze. Credit: Neuroscience News<\/p>\n<p>The\u00a0study will publish\u00a0on Wednesday (July 23) in the journal\u00a0Nature.<\/p>\n<p>\u201cOur study confirms that spatial memories in the brain aren\u2019t stable and fixed,\u201d said Northwestern\u2019s\u00a0Daniel Dombeck, the study\u2019s senior author.<\/p>\n<p>\u201cYou can\u2019t point to one group of neurons in the brain and say: \u2018That memory is stored right there.\u2019 Instead, we\u2019re finding that memories are passed among neurons. The exact same experience will involve different neurons every time. It\u2019s not a sudden change, but it slowly evolves.\u201d<\/p>\n<p>Dombeck is a professor of neurobiology and the Wender-Lewis Teaching and Research Professor at Northwestern\u2019s\u00a0Weinberg College of Arts and Sciences. The study was a collaboration among Dombeck and three members of his laboratory: Jason Climer, Heydar Davoudi and Jun Young Oh.\u00a0Climer, who is one of the study\u2019s co-first authors, is now an assistant professor of molecular and integrated physiology at the University of Illinois, Urbana-Champaign.<\/p>\n<p><strong>A memory mystery<\/strong><\/p>\n<p>Located deep within the brain\u2019s temporal lobe, the hippocampus stores memories related to spatial navigation. For decades, neurobiologists thought the same hippocampal neurons encoded memories of the same places. In other words, the path someone might take from their bedroom to their kitchen should activate the exact same sequence of neurons during each midnight walk for a glass of water.<\/p>\n<p>About 10 years ago, however, scientists imaged mice\u2019s brains as they ran through a maze. Even as the mice ran through the same maze day after day, different neurons fired during each run. Scientists wondered if the results were a fluke.<\/p>\n<p>\u201cPeople in the field started to wonder if the mice were truly having the same experience during each run through the maze,\u201d Dombeck said.<\/p>\n<p>\u201cMaybe they run faster on some days. Maybe the smells change from day to day. Maybe there are subtle, unavoidable environmental or behavioral differences that change the overall experience.\u201d<\/p>\n<p><strong>\u2018We controlled for everything we possibly could\u2019<\/strong><\/p>\n<p>To probe these questions, Dombeck and his team designed an experiment that gave them unprecedented control over the mice\u2019s sensory input.<\/p>\n<p>First, the team employed a cutting-edge multisensory virtual reality system \u2014\u00a0previously developed in Dombeck\u2019s laboratory\u00a0\u2014 to guarantee the animals\u2019 experienced identical visual cues. Then, the mice ran through the virtual maze on treadmills, ensuring precise measurement of speed. Finally, the scientists put\u00a0cones on the mice\u2019s noses\u00a0to provide identical smells for every session.<\/p>\n<p>After running the experiment several times, the results were clear. Even in a highly reproducible virtual world, the encoded neurons still drifted. The finding confirmed that the brain\u2019s spatial maps are inherently dynamic, constantly updating regardless of how static a space might be.<\/p>\n<p>\u201cWe controlled for everything we possibly could,\u201d Dombeck said.<\/p>\n<p>\u201cI was convinced we were going to get the opposite result and show that memories really are identical for the same space. But it turns out, they are not. A slightly different group of neurons activated each time.\u201d<\/p>\n<p><strong>Implications for aging<\/strong><\/p>\n<p>Although few patterns arose throughout the course of the experiment, Dombeck and his team did notice one consistent factor. The most excitable neurons, which were more easily activated, maintained more stable spatial memories throughout multiple runs through the virtual maze. Because neuron excitability decreases with age, the finding could help scientists understand the role of aging as it relates to the brain\u2019s ability to encode new memories.<\/p>\n<p>\u201cSome neurons do seem to be better at holding onto the original memory than others,\u201d Dombeck said.<\/p>\n<p>\u201cReally excitable neurons seem to store memories the best. The ones that fire more weakly are the ones that end up changing. So there does seem to be some small component of the original memory that\u2019s still there in this small fraction of neurons.\u201d<\/p>\n<p>Dombeck and his team are still pondering why the activated neurons change even though the space remains exactly the same. Although he\u2019s still unsure, Dombeck said the reason might be related to time.<\/p>\n<p>\u201cEven if you have the exact same experience, it has to be occurring at a different time,\u201d Dombeck said.<\/p>\n<p>\u201cIf I hike the same path twice, and it\u2019s identical both times, I probably still want to remember that I did the same hike twice. It\u2019s possible that the brain forces us to take very similar experiences that occur at different times and remember them in slightly different ways. That gives us access to memories of those individual experiences.\u201d<\/p>\n<p><strong>Funding: <\/strong>The study, \u201cHippocampal representations drift in stable multisensory environments,\u201d was supported by the National Institutes of Health (grant number\u00a0R01MH101297, T32AG020506 and 1F32NS116023).<\/p>\n<p>About this memory and neuroscience research news<\/p>\n<p class=\"has-background\" style=\"background-color:#ffffe8\"><strong>Author: <\/strong><a href=\"http:\/\/neurosciencenews.com\/cdn-cgi\/l\/email-protection#fb9a969a959f9a9694bb9594898f938c9e888f9e8995d59e9f8e\" target=\"_blank\" rel=\"noreferrer noopener\">Amanda Morris<\/a><br \/><strong>Source: <\/strong><a href=\"https:\/\/northwestern.edu\" target=\"_blank\" rel=\"noreferrer noopener\">Northwestern University<\/a><br \/><strong>Contact: <\/strong>Amanda Morris \u2013 Northwestern University<br \/><strong>Image: <\/strong>The image is credited to Neuroscience News<\/p>\n<p class=\"has-background\" style=\"background-color:#ffffe8\"><strong>Original Research: <\/strong>Closed access.<br \/>\u201c<a href=\"https:\/\/dx.doi.org\/10.1038\/s41586-025-09245-y\" target=\"_blank\" rel=\"noreferrer noopener\">Hippocampal representations drift in stable multisensory environments<\/a>\u201d by Daniel Dombeck et al. Nature<\/p>\n<p><strong>Abstract<\/strong><\/p>\n<p><strong>Hippocampal representations drift in stable multisensory environments<\/strong><\/p>\n<p>Experiments that track hippocampal place cells in mice navigating the same real environment have found significant changes in neural representations over a period of days.<\/p>\n<p>However, whether such \u2018representational drift\u2019 serves an intrinsic function, such as distinguishing similar experiences that occur at different times, or is instead observed due to subtle differences in the sensory environment or behaviour, remains unresolved.<\/p>\n<p>Here we used the experimental control offered by a multisensory virtual reality system to determine that differences in sensory environment or behaviour do not detectably change drift rate.<\/p>\n<p>We also found that the excitability of individual place cells was most predictive of their representational drift over subsequent days, with more excitable cells exhibiting less drift.<\/p>\n<p>These findings establish that representational drift occurs in mice even with highly reproducible environments and behaviour and highlight neuronal excitability as a key factor of long-term representational stability.<\/p>\n","protected":false},"excerpt":{"rendered":"Summary: New research shows that our brain\u2019s internal map rewrites itself every time we navigate a familiar environment.&hellip;\n","protected":false},"author":3,"featured_media":88284,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[39032,827,38835,3810,829,831,22190,59216,159,67,132,68],"class_list":{"0":"post-88283","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-brain-mapping","9":"tag-brain-research","10":"tag-hippocampus","11":"tag-memory","12":"tag-neurobiology","13":"tag-neuroscience","14":"tag-northwestern-university","15":"tag-place-cells","16":"tag-science","17":"tag-united-states","18":"tag-unitedstates","19":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/114907506620172764","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/88283","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=88283"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/88283\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/88284"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=88283"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=88283"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=88283"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}