{"id":396063,"date":"2026-04-16T23:47:09","date_gmt":"2026-04-16T23:47:09","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/396063\/"},"modified":"2026-04-16T23:47:09","modified_gmt":"2026-04-16T23:47:09","slug":"with-navigating-nematodes-scientists-map-out-how-brains-implement-behaviors-mit-news","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/396063\/","title":{"rendered":"With navigating nematodes, scientists map out how brains implement behaviors | MIT News"},"content":{"rendered":"

Animal behavior reflects a complex interplay between an animal\u2019s brain and its sensory surroundings. Only rarely have scientists been able to discern how actions emerge from this interaction. A new open-access study in Nature Neuroscience<\/a> by researchers in The Picower Institute for Learning and Memory at MIT offers one example by revealing how circuits of neurons within C. elegans nematode worms respond to odors and generate movement as they pursue of smells they like and evade ones they don\u2019t.<\/p>\n

\u201cAcross the animal kingdom, there are just so many remarkable behaviors,\u201d says study senior author Steven Flavell, associate professor in the Picower Institute and MIT\u2019s Department of Brain and Cognitive Sciences and an investigator of the Howard Hughes Medical Institute. \u201cWith modern neuroscience tools, we are finally gaining the ability to map their mechanistic underpinnings.\u201d<\/p>\n

By the end of the study, which former graduate student Talya Kramer PhD \u201925 led as her doctoral thesis research, the team was able to show exactly which neurons in the worm\u2019s brain did which of the jobs needed to sense where smells were coming from, plan turns toward or away from them, shift to reverse (like old-fashioned radio-controlled cars, C. elegans worms turn in reverse), execute the turns, and then go back to moving forward. Not only did the study reveal the sequence and each neuron\u2019s role in it, but it also demonstrated that worms are more skillful and intentional in these actions than perhaps they\u2019ve received credit for. And finally, the study demonstrated that it\u2019s all coordinated by the neuromodulatory chemical tyramine.<\/p>\n

\u201cOne thing that really excited us about this study is that we were able to see what a sensorimotor arc looks like at the scale of a whole nervous system: all the bits and pieces, from responses to the sensory cue until the behavioral response is implemented,\u201d Flavell says.<\/p>\n

Seeing the sequence<\/p>\n

To do the research, Kramer put worms in dishes with spots of odors they\u2019d either want to navigate toward or slither away from. With the lab\u2019s custom microscopes and software, she and her co-authors could track how the worms navigated and all the electrical activity of more than 100 neurons in their brains during those behaviors (the worms only have 302 neurons total).<\/p>\n

The surveillance enabled Kramer, Flavell, and their colleagues to observe that the worms weren\u2019t just ambling randomly until they happened to get where they\u2019d want to be. Instead, the worms would execute turns with advantageous timing and at well-chosen angles. The worms seemed to know what they were doing as they navigated along the gradients of the odors.<\/p>\n

Inside their heads, patterns of electrical activity among a cohort of 10 neurons (indicated by flashing green light tied to the flux of calcium ions in the cells), revealed the sequence of neural activation that enabled the worms to execute these sensible sensory-guided motions: forward, then into reverse, then into the turn, and then back to forward. Particular neurons guided each of these steps, including detecting the odors, planning the turn, switching into reverse, and then executing the turns.<\/p>\n

A couple of neurons stood out as key gears in the sequence. A neuron called SAA proved pivotal for integrating odor detection with planning movement, as its activity predicted the direction of the eventual turn. Several neurons were flexible enough to show different activity patterns depending on factors such as where the odors were and whether the worm was moving forward or in reverse.<\/p>\n

And if the neurons are indeed turning and shifting gears, then the neuromodulator tyramine (the worm analog of norepinephrine) was the signal essential to switch their gears. After the worms started moving in reverse, tyramine from the neuron RIM enabled other neurons in the sequence to change their activity appropriately to execute the turns. In several experiments the scientists knocked out RIM tyramine and saw that the navigation behaviors and the sequence of neural activity largely fell apart.<\/p>\n

\u201cThe neuromodulator tyramine plays a central role in organizing these sequential brain activity patterns,\u201d Flavell says.<\/p>\n

In addition to Flavell and Kramer, the paper\u2019s other authors are Flossie Wan, Sara Pugliese, Adam Atanas, Sreeparna Pradhan, Alex Hiser, Lillie Godinez, Jinyue Luo, Eric Bueno, and Thomas Felt.<\/p>\n

A MathWorks Science Fellowship, the National Institutes of Health, the National Science Foundation, The McKnight Foundation, The Alfred P. Sloan Foundation, the Freedom Together Foundation, and HHMI provided funding to support the work.<\/p>\n","protected":false},"excerpt":{"rendered":"Animal behavior reflects a complex interplay between an animal\u2019s brain and its sensory surroundings. Only rarely have scientists…\n","protected":false},"author":2,"featured_media":396064,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[188000,187999,85,188001,46,188003,45700,187518,141,188004,188005,188006,188002],"class_list":{"0":"post-396063","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-c-elegans-behavior","9":"tag-hhmi","10":"tag-il","11":"tag-intentional-behavior","12":"tag-israel","13":"tag-mapping-brain-activity","14":"tag-mit-picower-institute","15":"tag-olfaction","16":"tag-science","17":"tag-sensory-guided-motion","18":"tag-steven-flavell","19":"tag-talya-kramer","20":"tag-tyramine"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/396063","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=396063"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/396063\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/396064"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=396063"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=396063"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=396063"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}