{"id":2690,"date":"2022-09-14T10:28:49","date_gmt":"2022-09-14T00:28:49","guid":{"rendered":"https:\/\/www.cognav.net\/?p=2690"},"modified":"2022-09-14T10:28:49","modified_gmt":"2022-09-14T00:28:49","slug":"howretrohippocampal-neurons-encode-location-through-ramping-activity%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/braininspirednavigation.com\/?p=2690","title":{"rendered":"Howretrohippocampal neurons encode location through ramping activity\uff1f"},"content":{"rendered":"<p style=\"text-align: justify;\">Tennant, Sarah A., Harry Clark, Ian Hawes, Wing Kin Tam, Junji Hua, Wannan Yang, Klara Z. Gerlei, Emma R. Wood, and Matthew F. Nolan. &#8220;<strong><a href=\"https:\/\/doi.org\/10.1016\/j.cub.2022.08.050\">Spatial representation by ramping activity of neurons in the retrohippocampal cortex<\/a><\/strong>.&#8221; Current Biology,\u00a0<span class=\"article-header__publish-date bulleted\"><span class=\"article-header__publish-date__value\">September 12, 2022\u00a0<\/span><\/span><span class=\"article-header__doi bulleted\"><span class=\"article-header__doi__label\">DOI:<\/span><a class=\"article-header__doi__value\" href=\"https:\/\/doi.org\/10.1016\/j.cub.2022.08.050\">https:\/\/doi.org\/10.1016\/j.cub.2022.08.050<\/a><\/span><\/p>\n<p style=\"text-align: justify;\">Summary<br \/>\n&#8220;Neurons in the retrohippocampal cortices play crucial roles in spatial memory. <strong><span style=\"color: #ff0000;\">Many retrohippocampal neurons have firing fields that are selectively active at specific locations, with memory for rewarded locations associated with reorganization of these firing fields.<\/span> <span style=\"color: #ff0000;\">Whether this is the sole strategy for representing spatial memories is unclear<\/span><\/strong>. Here, we demonstrate that during a spatial memory task retrohippocampal neurons encode location through ramping activity that extends across segments of a linear track approaching and following a reward, with the rewarded location represented by offsets or switches in the slope of the ramping activity. Ramping representations could be maintained independently of trial outcome and cues marking the reward location, indicating that they result from recall of the track structure. When recorded in an open arena, neurons that generated ramping activity during the spatial memory task were more numerous than grid or border cells, with a majority showing spatial firing that did not meet criteria for classification as grid or border representations. Encoding of rewarded locations through offsets and switches in the slope of ramping activity also emerged in recurrent neural network models trained to solve a similar spatial memory task. Impaired performance of model networks following disruption of outputs from ramping neurons is consistent with this coding strategy supporting navigation to recalled locations of behavioral significance.<strong><span style=\"color: #ff0000;\"> Our results suggest that encoding of learned spaces by retrohippocampal networks employs both discrete firing fields and continuous ramping representations.<\/span><\/strong> We hypothesize that retrohippocampal ramping activity mediates readout of learned models for goal-directed navigation.&#8221;<\/p>\n<p style=\"text-align: justify;\">Tennant, Sarah A., Harry Clark, Ian Hawes, Wing Kin Tam, Junji Hua, Wannan Yang, Klara Z. Gerlei, Emma R. Wood, and Matthew F. Nolan. &#8220;<strong><a href=\"https:\/\/doi.org\/10.1016\/j.cub.2022.08.050\">Spatial representation by ramping activity of neurons in the retrohippocampal cortex<\/a><\/strong>.&#8221; Current Biology,\u00a0<span class=\"article-header__publish-date bulleted\"><span class=\"article-header__publish-date__value\">September 12, 2022\u00a0<\/span><\/span><span class=\"article-header__doi bulleted\"><span class=\"article-header__doi__label\">DOI:<\/span><a class=\"article-header__doi__value\" href=\"https:\/\/doi.org\/10.1016\/j.cub.2022.08.050\">https:\/\/doi.org\/10.1016\/j.cub.2022.08.050<\/a><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tennant, Sarah A., Harry Clark, Ian Hawes, Wing Kin Tam, Junji Hua, Wannan Yang, Klara Z. Gerlei, Emma R. Wood, and Matthew F. Nolan. &#8220;Spatial representation by ramping activity of neurons in the retrohippocampal cortex.&#8221; Current Biology,\u00a0September 12, 2022\u00a0DOI:https:\/\/doi.org\/10.1016\/j.cub.2022.08.050 Summary &#8220;Neurons in the retrohippocampal cortices play crucial roles in spatial memory. Many retrohippocampal neurons have [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[96,346],"tags":[1070,1069,1071,375],"_links":{"self":[{"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/posts\/2690"}],"collection":[{"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2690"}],"version-history":[{"count":1,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/posts\/2690\/revisions"}],"predecessor-version":[{"id":2691,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/posts\/2690\/revisions\/2691"}],"wp:attachment":[{"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2690"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2690"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2690"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}