Anxiety could be considered a result of the unconscious assessment of the environment and detection of a potential danger. Thus, moderate anxiety is advantageous for survival while excessive anxiety can lead to psychiatric disorders. Researchers at Tohoku University have shown that neuron and astrocyte interactions in the habenula set the tone of anxiety by studying the blues in the minds of mice faced with a floor filled with marbles.
Support our science by reposting my post below in X (twitter)! https://twitter.com/KoMatsui/status/1758330608756089287 Wanqin Tan, Yoko Ikoma, Yusuke Takahashi, Ayumu Konno, Hirokazu Hirai, Hajime Hirase, Ko Matsui* (2024) Anxiety control by astrocytes in the lateral habenula. Neuroscience Research, available online, Feb 2, 2024. https://doi.org/10.1016/j.neures.2024.01.006 Anxiety may appear to be an irrational emotion having only a negative impact on our life. However, well-tuned anxiety is a guide provided by our unconsciousness which allows us to navigate the hidden dangers. Such tuning may be accomplished by the actions of the habenula. The habenula are a pair of small nuclei located above the thalamus. It is one of the few brain regions that controls both dopaminergic and serotonergic systems. As these neuromodulators play essential roles in a wide range of motivational and cognitive functions, habenula neuronal circuits are potentially relevant to controlling anxiety. Mice have never encountered smooth glass marbles and they perceive them as potentially harmful objects. To escape from the uneasiness, mice tend to bury the marble in saw dust bedding to hide these uncomfortable objects out of sight. Here, the researchers created a chamber filled with marbles to create an inescapable maximum anxiety environment. Increased neuronal activity in the theta band (5 to 10 Hz) frequency, increase in the local brain blood volume, and acidification of the astrocytes in the habenula were found when the mice were placed in the all-marble cage. When the habenular astrocytes were artificially alkalized to counter the acidification, the theta band neuronal activity dissipated. When the mice were allowed to choose between the brightly lit all-marble cage and a dark and comfortable cage, the mice naturally chose to stay in the dark cage. However, when the habenular astrocytes were optogenetically alkalized, the mice ventured to travel more in the bright cage. Astrocytes are non-neuronal cells that occupy approximately half of the brain. They have been shown to control the local ionic and metabotropic environment in the brain. Astrocytes also release transmitters that can affect neuronal activity in the vicinity. The results of this study suggest that the theta band habenular neuronal activity is regulated by the activity of astrocytes. Thus, habenular astrocytes were considered to play a role in regulating anxiety. Future treatment of anxiety disorders may be realized by developing a therapeutic strategy that adjusts astrocyte activity in the habenula.Habenular astrocytes tune the marble blues. Methods to cope with anxiety could be expected to be developed. Press Release - Tohoku University https://www.tohoku.ac.jp/en/press/habenular_astrocytes_tuning_anxiety_with_marble_blues.html Graduate School of Life Sciences https://www.lifesci.tohoku.ac.jp/en/research/results/detail---id-51803.html Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University http://www.ims.med.tohoku.ac.jp/matsui/
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Imagine there is no social conflict. It's easy if we could harness the innate ability of the cerebellar glia to control aggression. Imagine all the people living life in peace. You-who-fu-fu-fu.
Support our science by reposting my post below in X (twitter)! https://twitter.com/KoMatsui/status/1732049741146656958 Yuki Asano, Daichi Sasaki, Yoko Ikoma, Ko Matsui* (2023) Glial tone of aggression. Neuroscience Research, available online, Nov 24, 2023. https://doi.org/10.1016/j.neures.2023.11.008 Uncontrolled aggression can lead to conflict, violence and negative consequences for individuals and society. Yet, it is an instinctive behavior found in many species that may be necessary for survival. The key is managing and channeling aggression. Researchers at Tohoku University have demonstrated that neuron-glial interactions in the cerebellum set the tone of aggression, suggesting that future therapeutic methods could rely on adjusting glial activity there to manage anger and aggression. The results of this study suggest that the theta band cerebellar neuronal activity is regulated by the activity of Bergmann glial cells, thereby demonstrating that cerebellar glial cells play a role in regulating aggression in mice. Press Release - Tohoku University https://www.tohoku.ac.jp/en/press/glial_tone_of_aggression.html Graduate School of Life Sciences https://www.lifesci.tohoku.ac.jp/en/research/results/detail---id-51675.html Researchers at Tohoku University have discovered that there are two parallel processes involved in memory formation when a mouse performs a motor learning task. One process occurs during training and is called online learning, while the other happens during the resting period and is called offline learning. Online learning can be boosted or reduced by manipulating glial activity, but offline learning remains unaffected by these manipulations. Understanding the cellular mechanisms underlying these independent parallel memory formation processes may lead to the development of efficient rehabilitation after strokes, dementia treatment, or realizing extended intelligence.
The findings were detailed in the journal Glia on June 27, 2023. We have long been aware that performance may not improve much during training, but increase the next day. Alternatively, excelling during training may not carry over to the next day. Here, the researchers have shown that online and offline learning are indeed separate parallel processes governed by distinct cellular mechanisms. Glial cells in the brain occupy almost as much volume as neurons; however, they were simply thought to fill the gaps between neurons. Recently, glial cells have been shown to be involved in the information processing in the brain, albeit in quite a different manner than that of neurons. By releasing gliotransmitters, such as glutamate, glial cells can modulate the easiness of memory formation; a process termed meta-plasticity. The researchers used the horizontal optokinetic response paradigm to understand the role of glial cells in online and offline learning. When mice were presented with a horizontally oscillating visual stimulus, their eyes followed the screen with a lesser amplitude relative to the presented stimulus. With prolonged and repeated presentation, the amplitude increased until their eyes could perfectly pursue the screen. The performance increase during the 15 min presentation was termed online learning and the increase during the 1-hour resting period, which the mice spent in the dark, was termed offline learning. Light-activated proteins, channelrhodopsin-2 (ChR2) or archaerhodopsin (ArchT) were genetically expressed specifically in glial cells to manually control glial activity. When glutamate release from glial cells was facilitated by photo-activating ChR2, online learning was augmented. However, the benefit from glial modulation was short-lasting and the performance of eye movement soon became indistinguishable from control. When the glial activity was inhibited by ArchT, online learning was completely suppressed. Interestingly, offline learning proceeded normally even in the complete absence of online learning. "Our data shows that short- and long-term memory formation is not a serial process, but rather it is a parallel and independent process," says Professor Ko Matsui of the Super-network Brain Physiology lab at Tohoku University, who led the research. "Agonizing over the performance gained during each training or study session is unnecessary, as long-lasting achievement depends on a totally separate process." Kanaya T, Ito R, Morizawa YM, Sasaki D, Yamao H, Ishikane H, Hiraoka Y, Tanaka K, Matsui K* (2023) Glial modulation of the parallel memory formation. Glia, published online. https://doi.org/10.1002/glia.24431 Press release: https://www.tohoku.ac.jp/en/press/glial_control_of_parallel_memory_processing.html Professor Ko Matsui lab Super-network Brain Physiology Graduate School of Life Sciences, Tohoku University http://www.ims.med.tohoku.ac.jp/matsui/ * Please retweet to my post on twitter to support our science!! Just by clicking on "retweet" to my post with the DOI article information, your attention will be counted in the Altmetric score. "like!" does not count and facebook shares also does not seem to count. Please visit twitter and simply retweet my post!! https://twitter.com/KoMatsui/status/1673641013825642497 Super acidified to announce our new paper!! Using the new design FRET fiber photometry method, acid shifts were captured in the dreaming glia.
* Please use twitter and tweet including the DOI or retweet to my tweet below to contribute to increasing our Altmetric score and supporting our science! Ikoma Y, Takahashi Y, Sasaki D, Matsui K (2023) Properties of REM sleep alterations with epilepsy. Brain DOI: https://doi.org/10.1093/brain/awac499 Professor Ko Matsui's tweet (please retweet. Like! does not count in Altmetric): https://twitter.com/KoMatsui/status/1631568237686296576 Upon REM sleep, astrocytes reacted with acidic shifts, calcium reduction and vascular expansion. These local brain environmental changes preceded the REM shifts detected with EEG by ~20 sec. Artificial acidification of astrocytes in lateral hypothalamus with photoactivation of ChR2 expressed in astrocytes induced a REM-like shift in behavior and EEG. These data suggest that astrocyte and vascular changes may serve as one of the drives to brain state changes. Furthermore, the acid response in REM sleep was exacerbated after the epileptic kindling protocol. REM sleep characteristics may provide a biomarker for the severity of epilepsy. Controlling of astrocytes' pH could potentially be used for the prevention of epileptogenesis. Super-network Brain Physiology Grad Sch Life Sci, Tohoku Univ http://www.ims.med.tohoku.ac.jp/matsui/ Excited to announce our new paper published in the journal, Brain. Optical fibers were used to probe the glial and vascular reactions in epilepsy using a mouse model. A new design FRET fiber photometry method offers detection of Ca2+, pH, and brain blood volume dynamics. Early epileptic seizures produced astrocytic alkalization while developed seizures resulted in acidification in the lateral hypothalamus. This dual phase pH reaction of astrocytes suggests a need for individualized medicine depending on the stage for the possible prevention and treatment of epilepsy.
Thrilled to announce our new paper in Nature Neuroscience. It is now introduced on the cover of the November issue.
Morizawa YM, Matsumoto M, Nakashima Y, Endo N, Aida T, Ishikane H, Beppu K, Moritoh S, Inada H, Osumi N, Shigetomi E, Koizumi S, Yang G, Hirai H, Tanaka K, Tanaka KF, Ohno N, Fukazawa Y, Matsui K (2022) Synaptic pruning through glial synapse engulfment during motor learning. Nature Neuroscience, 25, 1458-1469. https://doi.org/10.1038/s41593-022-01184-5 Tohoku University researchers have shown that Bergmann glial cells, astrocyte-like cells in the cerebellum, 'eat' their neighboring neuronal elements within healthy living brain tissue. Synapses - structures that allow neurons to pass signals to one another - are regularly pruned throughout a brain's development to improve its efficiency. Disruption of this is thought to lead to various brain disorders. The researchers' findings, which were detailed in the journal Nature Neuroscience, discovered that Bergmann glial engulfing of synapses was enhanced during motor learning in mice's cerebellum, an important brain region for learning. Moreover, pharmacological blocking this engulfment inhibited synaptic structural changes, resulting in part of the learning and memory process being lost When cells engulf neighboring cells to flush out debris and pathogens, it is called phagocytosis. Phagocytosis by microglia, immune cells in the brain, in damaged and diseased brain tissue has long been recognized. Recent reports have established that astrocytes and microglia phagocytose neuronal elements, including synapses during early brain development or when dramatic neuronal network remodeling occurs in the diseased brain. Tracing engulfed materials is challenging in healthy brains, since the lysosomes in the glia quickly degenerate the proteins. Matsui and his team turned to the degeneration-resistant fluorescent protein pHRed to alleviate this problem. Using high-resolution 3D electron microscopy, they captured the Bergmann glia nibbling on synapses parts and other neuronal parts in adult healthy mice brains. Furthermore, glial phagocytosis was enhanced in brain tissues taken after cerebellar-dependent motor learning tasks. "Our finding provides a novel glial mechanism in synaptic plasticity linking learning and memory. It is possible that the phagocytic capacity of glia might be variable under the certain states of our mind and glia may play a pivotal role in meta-plasticity of memory formation," said Matsui. Lead study investigator Dr Yosuke Morizawa says that their discoveries could have possible implications for explaining why synaptic shrinkage and loss occur in depression, schizophrenia, and Alzheimer's disease. Shimoda Y, Beppu K, Ikoma Y, Morizawa YM, Zuguchi S, Hino U, Yano R, Sugiura Y, Moritoh S, Fukazawa Y, Suematsu M, Mushiake H, Nakasato N, Iwasaki M, Tanaka KF, Tominaga T, Matsui K* (2022) Optogenetic stimulus-triggered acquisition of seizure resistance. Neurobiology of Disease, 163: 1055602. DOI: https://doi.org/10.1016/j.nbd.2021.105602 https://www.sciencedirect.com/science/article/pii/S096999612100351X?via%3Dihub Tohoku University scientists have shown that resilience to epilepsy could be acquired with certain stimulation paradigm using experimental animals. Frequent occurrence of neuronal hyperactivity and seizures has been shown to induce epileptogenesis. Here, we show that daily neuron-to-astrocyte signaling could prompt release of endogenous inhibitory transmitter, adenosine, from glial cells. The novel neuronal stimulation protocol brought out the homeostatic potential of glial cells and converted the brain of the rat to a state that is strongly resistant to seizure induction.
Annual Review 神経 2021(中外医学社)
III. Clinical Topics 11.機能性疾患 1 てんかん治療における迷走神経刺激法の機序 (pp. 337 - 343) 著者: 東北大学大学院生命科学研究科超回路脳機能分野 松井 広 http://www.chugaiigaku.jp/item/detail.php?id=3543 Hatakeyama N, Unekawa M, Murata J, Tomita Y, Suzuki N, Nakahara J, Takuwa H, Kanno I, Matsui K, Tanaka KF, Masamoto K (2021) Differential pial and penetrating arterial responses examined by optogenetic activation of astrocytes and neurons.
J Cereb Blood Flow Metab, 41: 2676-2689. https://doi.org/10.1177/0271678X211010355 |
Prof. Dr. Ko Matsui
In search for our mind, we look deeply into the super-network of neurons and glial cells. Graduate School of Life Sciences @ Tohoku University. Archives
February 2024
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