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    New study uncovers brain circuits that control fear responses

    Images of the ventral lateral geniculate nucleus (vLGN) with axonal processes (inputs) from different locations in the visual part of the cerebral cortex labeled with different colors. These inputs may give the cerebral cortex the ability to regulate instinctive threat responses via vLGN, depending on animal knowledge. Credits: © Sainsbury Wellcome Center

    Based on previous experience, researchers at the Sainsbury Wellcome Center have discovered a brain mechanism that allows mice to disable their instincts.

    Study published today NeuronIdentify new brain circuits in the ventral lateral geniculate nucleus (vLGN), an inhibitory structure of the brain. Neuroscientists say that when activity in this area of ​​the brain is suppressed, animals are more likely to escape danger in search of safety, whereas activation of vLGN neurons completes the escape response to imminent threats. I found it to be disabled.

    It ’s normal to experience fear Or anxiety in a particular situation, we can adjust our fear response according to our knowledge and circumstances. For example, waking up to a large nearby blast or bright light can cause a horrifying reaction. But if you have experienced fireworks before, your knowledge will prevent such reactions and you will be able to see them without fear. On the other hand, if you happen to be in a war zone, your fear response can be significantly increased.

    A lot of people Brain region It has previously been shown to be involved in the handling of perceived dangers and the mediation of fear responses, but the mechanism by which these responses are controlled remains unclear.Such control is very important as its failure can lead to Anxiety disorder It is believed that the circuits in the brain associated with fear and anxiety, such as phobia and post-traumatic stress disorder (PTSD), become overactive and pathologically increase the fear response.

    A new study by Professor Sonya Hofer’s research group at the Sainsbury Welcome Center at University College London used an established experimental paradigm in which mice fled to shelters in response to dark shadows over their heads. This looming stimulus simulates a predator moving from above towards the animal.

    Researchers have discovered that vLGN can control escape behavior in response to animal knowledge. Previous experience, And risk assessment in the current environment. When mice unexpectedly felt the threat was safe, the activity of a subset of the inhibitory neurons of vLGN was high, which could interfere with the threat response. In contrast, when mice expected danger, the activity of these neurons was low and animals were more likely to escape and seek safety.

    New research reveals brain circuits that control fear responses

    Researchers have found that a specific inhibitory brain region, vLGN, can regulate mouse instinctive escape behavior in response to previous experience and prediction of environmental hazards. Credits: © Sainsbury Wellcome Center

    “We believe that vLGN may act as an inhibitory gate that sets thresholds for susceptibility to potentially threatening stimuli, depending on animal knowledge,” said Dr. Alex Fratzl. I am. A student at Hofer Lab and the lead author of the treatise.

    The next piece of the puzzle that researchers are focusing on is determining other brain regions where vLGN interacts to achieve this inhibitory control of the defensive response.They are already one such brain region Superior colliculus In the midbrain.

    “We have found that vLGN specifically inhibits superior colliculus neurons that respond to visual threats, thereby specifically blocking the pathways in the brain that mediate the response to such threats. What you see can pose a danger like an approaching predator. ” Sonja Hofer, a professor at the Sainsbury Wellcome Center and the corresponding author of the treatise.

    New research reveals brain circuits that control fear responses

    vLGN specifically inhibits superior colliculus neurons in the midbrain region that respond to visual threats. It can specifically block pathways in the brain that mediate responses to such threats-what animals see can be dangerous. Credits: © Sainsbury Wellcome Center

    Humans do not have to worry too much about predators, but there are also instinctive fear reactions in certain situations.Therefore, it is hoped that clinical scientists will be able to see if one day they will respond. brain Human circuits have similar functions and will have clinical implications for the treatment of PTSD and other anxiety-related disorders in the future.


    How microcircuits in the brain regulate fear


    For more information:
    Flexible suppression control of visually evoked defensive behavior by the ventral lateral geniculate nucleus, Neuron (2021). DOI: 10.1016 / j.neuron.2021.09.003

    Provided by Sainsbury Welcome Center

    Quote: A new study found the horror response (October 5, 2021) obtained on October 5, 2021 from https://medicalxpress.com/news/2021-10-uncovers-brain-circuits-responses.html. Reveal the controlling brain circuit

    This document is subject to copyright. No part may be reproduced without written permission, except for fair transactions for personal investigation or research purposes. The content is provided for informational purposes only.

    New study uncovers brain circuits that control fear responses Source link New study uncovers brain circuits that control fear responses

    The post New study uncovers brain circuits that control fear responses appeared first on California News Times.

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