• Circuit that focuses attention brings in

    From ScienceDaily@1:317/3 to All on Thursday, April 21, 2022 22:30:46
    Circuit that focuses attention brings in wide array of inputs

    Date:
    April 21, 2022
    Source:
    Picower Institute at MIT
    Summary:
    With a comprehensive map of the wiring, researchers can now
    discern what information flows into the circuit to enable a key
    brain function.



    FULL STORY ==========================================================================
    In a new brain-wide circuit tracing study, scientists at MIT's Picower Institute for Learning and Memory focused selective attention on a circuit
    that governs, fittingly enough, selective attention. The comprehensive
    maps they produced illustrate how broadly the mammalian brain incorporates
    and integrates information to focus its sensory resources on its goals.


    ========================================================================== Working in mice, the team traced thousands of inputs into the circuit,
    a communication loop between the anterior cingulate cortex (ACC)
    and the lateral posterior (LP) thalamus. In primates the LP is called
    the pulvinar. Studies in humans and non-human primates have indicated
    that the byplay of these two regions is critical for brain functions
    like being able to focus on an object of interest in a crowded scene,
    said study co-lead author Yi Ning Leow, a graduate student in the lab
    of senior author Mriganka Sur, Newton Professor in MIT's Department of
    Brain and Cognitive Sciences. Research has implicated dysfunction in
    the circuit in attention-affecting disorders such as autism and ADHD.

    The new study in the Journal of Comparative Neurology extends what's known about the circuit by detailing it in mice, Leow said, importantly showing
    that the mouse circuit is closely analogous to the primate version even
    if the LP is proportionately smaller and less evolved than the pulvinar.

    "In these rodent models we were able to find very similar circuits,"
    Leow said.

    "So we can possibly study these higher order functions in mice as
    well. We have a lot more genetic tools in mice so we are better
    able to look at this circuit." The study, also co-led by former MIT undergraduate Blake Zhou, therefore provides a detailed roadmap in the experimentally accessible mouse model for understanding how the ACC and
    LP cooperate to produce selective attention. For instance, now that Leow
    and Zhou have located all the inputs that are wired into the circuit,
    Leow is tapping into those feeds to eavesdrop on the information they
    are carrying. Meanwhile, she is correlating that information flow with behavior.

    "This study lays the groundwork for understanding one of the most
    important, yet most elusive, components of brain function, namely our
    ability to selectively attend to one thing out of several, as well as
    switch attention," Sur said.



    ========================================================================== Broad input for a focused result Using virally mediated circuit tracing techniques pioneered by co-author Ian Wickersham, Principal Research
    Scientist of Brain and Cognitive Sciences at MIT, the team found
    distinct sources of input for the ACC and the LP. Generally speaking,
    the detailed study finds that the majority of inputs to the ACC were
    from frontal cortex areas that typically govern goal-directed planning
    and from higher visual areas. The bulk of inputs to the LP, meanwhile,
    were from deeper regions capable of providing context such as the
    mouse's needs, location and spatial cues, information about movement,
    and general information from a mix of senses.

    So even though focusing attention might seem like a matter of controlling
    the senses, Leow said, the circuit pulls in a lot of other information
    as well.

    "We're seeing that it's not just sensory -- there are so many inputs
    that are coming from non-sensory areas as well, both sub-cortically and cortically," she said. "It seems to be integrating a lot of different
    aspects that might relate to the behavioral state of the animal at a
    given time. It provides a way to provide a lot of internal and special
    context for that sensory information." Given the distinct sets of
    inputs to each region, the ACC may be tasked with focusing attention
    on a desired object, while the LP is modulating how the ACC goes about
    making those computations, accounting for what's going on both inside
    and outside the animal. Decoding just what that incoming contextual
    information is and what the LP tells the ACC, are the key next steps,
    Leow said. Another clear set of questions the study raises are what are
    the circuit's outputs. In other words, after it integrates all this
    information what does it do with it? The paper's other authors are
    Heather Sullivan and Alexandria Barlowe.

    A National Science Scholarship, the National Institutes of Health,
    and the JPB Foundation provided support for the study.


    ========================================================================== Story Source: Materials provided by Picower_Institute_at_MIT. Note:
    Content may be edited for style and length.


    ========================================================================== Journal Reference:
    1. Yi Ning Leow, Blake Zhou, Heather A. Sullivan, Alexandria
    R. Barlowe, Ian
    R. Wickersham, Mriganka Sur. Brain‐wide mapping of inputs
    to the mouse lateral posterior (LP/Pulvinar) thalamus-anterior
    cingulate cortex network. Journal of Comparative Neurology, 2022;
    DOI: 10.1002/cne.25317 ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2022/04/220421130938.htm

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