{"id":135700,"date":"2024-12-11T05:35:32","date_gmt":"2024-12-10T22:35:32","guid":{"rendered":"https:\/\/hotvideos24.online\/?p=135700"},"modified":"2024-12-11T05:35:32","modified_gmt":"2024-12-10T22:35:32","slug":"how-sleep-shapes-our-brains-mental-navigational-maps","status":"publish","type":"post","link":"https:\/\/hotvideos24.online\/?p=135700","title":{"rendered":"How Sleep Shapes Our Brain\u2019s Mental Navigational Maps"},"content":{"rendered":"<p> <script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-3711241968723425\"\r\n     crossorigin=\"anonymous\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-layout-key=\"-fb+5w+4e-db+86\"\r\n     data-ad-client=\"ca-pub-3711241968723425\"\r\n     data-ad-slot=\"7910942971\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><br \/>\n<\/p>\n<div>\n<p><strong>Summary: <\/strong>A new study reveals how the brain forms cohesive mental maps of spaces and highlights the critical role of sleep in this process. While \u201cplace cells\u201d in the hippocampus mark specific locations, weaker spatial cells stitch these points into a comprehensive cognitive map.<\/p>\n<p>Researchers observed that sleep refines these maps, allowing the brain to connect locations and encode them into a mental geography. This discovery underscores the importance of both subtle neural activity and rest in enhancing our ability to navigate and plan within our environments.<\/p>\n<p><strong>Key Facts:<\/strong><\/p>\n<ul class=\"wp-block-list\">\n<li><strong>Weakly Spatial Cells:<\/strong> These cells connect discrete place memories into a mental map, essential for navigation.<\/li>\n<li><strong>Role of Sleep:<\/strong> Sleep refines and strengthens neural connections, enhancing cognitive mapping.<\/li>\n<li><strong>Cognitive Maps:<\/strong> These maps offer schematic representations of spaces, enabling mental exploration and planning.<\/li>\n<\/ul>\n<p><strong>Source: <\/strong>Picower Institute at MIT<\/p>\n<p><strong>On the first day of your vacation in a new city your explorations expose you to innumerable individual places. While the memories of these spots (like a beautiful garden on a quiet side street) feel immediately indelible, it might be days before you have enough intuition about the neighborhood to direct a newer tourist to that same site and then maybe to the caf\u00e9 you discovered nearby. <\/strong><\/p>\n<p>A new study in mice by MIT neuroscientists at The Picower Insitute for Learning and Memory provides new evidence for how the brain forms cohesive cognitive maps of whole spaces and highlights the critical importance of sleep for the process.<\/p>\n<p>Scientists have known for decades that the brain devotes neurons in a region called the hippocampus to remembering specific locations. So-called \u201cplace cells\u201d reliably activate when an animal is at the location the neuron is tuned to remember.<\/p>\n<p>But more useful than having markers of specific spaces is having a mental model of how they all relate in a continuous overall geography.<\/p>\n<p>Though such \u201ccognitive maps\u201d were formally theorized in 1948, neuroscientists have remained unsure of how the brain constructs them.<\/p>\n<p>The new study in the December edition of\u00a0<em>Cell Reports<\/em>\u00a0finds that the capability may depend upon subtle but meaningful changes over days in the activity of cells that are only weakly attuned to individual locations, but that increase the robustness and refinement of the hippocampus\u2019s encoding of the whole space.<\/p>\n<p>With sleep, the study\u2019s analyses indicate, these \u201cweakly spatial\u201d cells increasingly enrich neural network activity in the hippocampus to link together these places into a cognitive map.<\/p>\n<p>\u201cOn day 1, the brain doesn\u2019t represent the space very well,\u201d said lead author Wei Guo, a research scientist in the lab of senior author\u00a0Matthew Wilson, Sherman Fairchild Professor in The Picower Institute and MIT\u2019s Departments of Biology and Brain and Cognitive Sciences.<\/p>\n<p> \u201cNeurons represent individual locations, but together they don\u2019t form a map. But on day 5 they form a map. If you want a map, you need all these neurons to work together in a coordinated ensemble.\u201d<\/p>\n<p><strong>Mice mapping mazes<\/strong><\/p>\n<p>To conduct the study, Guo and Wilson along with labmates Jie \u201cJack\u201d Zhang and Jonathan Newman introduced mice to simple mazes of varying shapes and let them explore them freely for about half an hour a day for several days. Importantly, the mice were not directed to learn anything specific through the offer of any rewards.<\/p>\n<p>They just wandered. Previous studies have shown that mice naturally demonstrate \u201clatent learning\u201d of spaces from this kind of unrewarded experience after several days.<\/p>\n<p>To understand how latent learning takes hold, Guo and his colleagues visually monitored hundreds of neurons in the CA1 area of the hippocampus by engineering cells to flash when a buildup of calcium ions made them electrically active.<\/p>\n<p>They not only recorded the neurons\u2019 flashes when the mice were actively exploring, but also while they were sleeping. Wilson\u2019s lab has shown that animals\u00a0\u201creplay\u201d\u00a0their previous journeys during sleep, essentially refining their memories by dreaming about their experiences.<\/p>\n<p>Analysis of the recordings showed that the activity of the place cells developed immediately and remained strong and unchanged over several days of exploration.\u00a0 But this activity alone wouldn\u2019t explain how latent learning or a cognitive map evolves over several days.<\/p>\n<p>So unlike in many other studies where scientists focus solely on the strong and clear activity of place cells, Guo extended his analysis to the more subtle and mysterious activity of cells that were not so strongly spatially tuned.<\/p>\n<p>Using an emerging technique called \u201cmanifold learning\u201d he was able to discern that many of the \u201cweakly spatial\u201d cells gradually correlated their activity not with locations, but with activity patterns among other neurons in the network.<\/p>\n<p>As this was happening, Guo\u2019s analyses showed, the network encoded a cognitive map of the maze that increasingly resembled the literal, physical space.<\/p>\n<p>\u201cAlthough not responding to specific locations like strongly spatial cells, weakly spatial cells specialize in responding to \u2018\u2018mental locations,\u2019\u2019 i.e., specific ensemble firing patterns of other cells,\u201d the study authors wrote.<\/p>\n<p>\u201cIf a weakly spatial cell\u2019s mental field encompasses two subsets of strongly spatial cells that encode distinct locations, this weakly spatial cell can serve as a bridge between these locations.\u201d<\/p>\n<p>In other words, the activity of the weakly spatial cells likely stitches together the individual locations represented by the place cells into a mental map.<\/p>\n<p><strong>The need for sleep<\/strong><\/p>\n<p>Studies by Wilson\u2019s lab and many others have shown that memories are consolidated, refined and processed by neural activity, such as replay, that occurs during sleep and rest.<\/p>\n<p> Guo and Wilson\u2019s team therefore sought to test whether sleep was necessary for the contribution of weakly spatial cells to latent learning of cognitive maps.<\/p>\n<p>To do this they let some mice explore a new maze twice during the same day with a three-hour siesta in between. Some of the mice were allowed to sleep but some were not. The ones that did showed a significant refinement of their mental map, but the ones that weren\u2019t allowed to sleep showed no such improvement.<\/p>\n<p>Not only did the network encoding of the map improve, but also measures of the tuning of individual cells during showed that sleep helped cells become better attuned both to places and to patterns of network activity, so called \u201cmental places\u201d or \u201cfields.\u201d<\/p>\n<p><strong>Mental map meaning<\/strong><\/p>\n<p>The \u201ccognitive maps\u201d the mice encoded over several days were not literal, precise maps of the mazes, Guo notes. Instead they were more like schematics. Their value is that they provide the brain with a topology that can be explored mentally, without having to be in the physical space.<\/p>\n<p>For instance, once you\u2019ve formed your cognitive map of the neighborhood around your hotel, you can plan the next morning\u2019s excursion (e.g. you could imagine grabbing a croissant at the bakery you observed a few blocks west and then picture eating it on one of those benches you noticed in the park along the river).<\/p>\n<p>Indeed, Wilson hypothesized that the weakly spatial cells\u2019 activity may be overlaying salient non-spatial information that brings additional meaning to the maps (i.e. the idea of a bakery is not spatial, even if it\u2019s closely linked to a specific location). The study, however, included no landmarks within the mazes and did not test any specific behaviors among the mice.<\/p>\n<p> But now that the study has identified that weakly spatial cells contribute meaningfully to mapping, Wilson said future studies can investigate what kind of information they may be incorporating into the animals\u2019 sense of their environments. We seem to intuitively regard the spaces we inhabit as more than just sets of discrete locations.<\/p>\n<p>\u201cIn this study we focused on animals behaving naturally and demonstrated that during freely exploratory behavior and subsequent sleep, in the absence of reinforcement, substantial neural plastic changes at the ensemble level still occur,\u201d the authors concluded.<\/p>\n<p>\u201cThis form of implicit and unsupervised learning constitutes a crucial facet of human learning and intelligence, warranting further in-depth investigations.\u201d<\/p>\n<p><strong>Funding: <\/strong>The Freedom Together Foundation, The Picower Institute for Learning and Memory and the National Institutes of Health funded the study.<\/p>\n<h2 class=\"wp-block-heading\">About this sleep and neuroscience research news<\/h2>\n<p class=\"has-background\" style=\"background-color:#ffffe8\"><strong>Author: <\/strong><a href=\"http:\/\/neurosciencenews.com\/cdn-cgi\/l\/email-protection#cfabaeb9a6aba5a08fa2a6bbe1aaabba\" target=\"_blank\" rel=\"noreferrer noopener\">David Orenstein<\/a><br \/><strong>Source: <\/strong><a href=\"https:\/\/mit.edu\" target=\"_blank\" rel=\"noreferrer noopener\">Picower Institute at MIT<\/a><br \/><strong>Contact: <\/strong>David Orenstein \u2013 Picower Institute at MIT<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>Open access.<br \/>\u201c<a href=\"https:\/\/dx.doi.org\/10.1016\/j.celrep.2024.115028\" target=\"_blank\" rel=\"noreferrer noopener\">Latent learning drives sleep-dependent plasticity in distinct CA1 subpopulations<\/a>\u201d by Matthew Wilson et al. <em>Cell Reports<\/em><\/p>\n<hr class=\"wp-block-separator has-text-color has-pale-cyan-blue-color has-alpha-channel-opacity has-pale-cyan-blue-background-color has-background\"\/>\n<p><strong>Abstract<\/strong><\/p>\n<p><strong>Latent learning drives sleep-dependent plasticity in distinct CA1 subpopulations<\/strong><\/p>\n<p>Latent learning is a process that enables the brain to transform experiences into \u201ccognitive maps,\u201d a form of implicit memory, without requiring reinforced training.<\/p>\n<p>To investigate its neural mechanisms, we record from hippocampal neurons in mice during latent learning of spatial maps and observe that the high-dimensional neural state space gradually transforms into a low-dimensional manifold that closely resembles the physical environment.<\/p>\n<p>This transformation process is associated with the neural reactivation of navigational experiences during sleep.<\/p>\n<p>Additionally, we identify a subset of hippocampal neurons that, rather than forming place fields in a novel environment, maintain weak spatial tuning but gradually develop correlated activity with other neurons.<\/p>\n<p>The elevated correlation introduces redundancy into the ensemble code, transforming the neural state space into a low-dimensional manifold that effectively links discrete place fields of place cells into a map-like structure.<\/p>\n<p>These results suggest a potential mechanism for latent learning of spatial maps in the hippocampus.<\/p>\n<p> <!-- Form created by Optin Forms plugin by WPKube: create beautiful optin forms with ease! --> <!-- https:\/\/wpkube.com\/ --><!--optinforms-form5-container--> <!-- \/ Optin Forms --> <\/div>\n<p><script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-3711241968723425\"\r\n     crossorigin=\"anonymous\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-layout-key=\"-fb+5w+4e-db+86\"\r\n     data-ad-client=\"ca-pub-3711241968723425\"\r\n     data-ad-slot=\"7910942971\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><br \/>\n<br \/><div data-type=\"_mgwidget\" data-widget-id=\"1660802\">\r\n<\/div>\r\n<script>(function(w,q){w[q]=w[q]||[];w[q].push([\"_mgc.load\"])})(window,\"_mgq\");\r\n<\/script>\r\n<br \/>\n<br \/><a href=\"https:\/\/neurosciencenews.com\/navigation-sleep-brain-mapping-28229\/\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Summary: A new study reveals how the brain forms cohesive mental maps of spaces and highlights the critical role of sleep in this process. While \u201cplace cells\u201d in the hippocampus &hellip; <a href=\"https:\/\/hotvideos24.online\/?p=135700\" class=\"more-link\">Read More<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-135700","post","type-post","status-publish","format-standard","hentry","category-health","entry"],"_links":{"self":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts\/135700","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=135700"}],"version-history":[{"count":0,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts\/135700\/revisions"}],"wp:attachment":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=135700"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=135700"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=135700"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}