{"id":16376,"date":"2022-01-18T13:14:58","date_gmt":"2022-01-18T13:14:58","guid":{"rendered":"https:\/\/clinlabint.com\/?p=16376"},"modified":"2022-01-20T12:36:03","modified_gmt":"2022-01-20T12:36:03","slug":"researchers-create-mind-blowing-tool-to-visualise-millions-of-neuronal-synapses-in-mouse-brain","status":"publish","type":"post","link":"https:\/\/clinlabint.com\/researchers-create-mind-blowing-tool-to-visualise-millions-of-neuronal-synapses-in-mouse-brain\/","title":{"rendered":"Researchers create mind-blowing tool to visualise millions of neuronal synapses in mouse brain"},"content":{"rendered":"
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\r\n\"Bio-Rad<\/a>\r\n<\/p>\n<\/div><\/section><\/div>

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Researchers create mind-blowing tool to visualise millions of neuronal synapses in mouse brain<\/h1>\/ in E-News<\/a> <\/span><\/span><\/header>\n<\/div><\/section>
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To solve the mysteries of how learning and memory occur, Johns Hopkins Medicine scientists have created a system to track millions of connections among brain cells in mice \u2013 all at the same time \u2013 when the animals\u2019 whiskers are tweaked, an indicator for learning.<\/p>\n

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Researchers say the new tool gives an unprecedented view of brain cell activity in a synapse.<\/p>\n

\u201cIt was science fiction to be able to image nearly every synapse in the brain and watch a change in behaviour,\u201d says Richard Huganir, Ph.D., Bloomberg Distinguished Professor of Neuroscience and Psychological and Brain Sciences at The Johns Hopkins University and director of the Department of Neuroscience at the Johns Hopkins University School of Medicine.<\/p>\n

A summary of the research was published in the journal eLife.<\/p>\n

The researchers never thought they\u2019d be able to see brain activity on such a massive scale. They say that before developing the tool, their ability to see brain cell activity was like looking up in the night sky with bare eyes and seeing billions of stars. \u201cIt\u2019s like we can see and track each of the stars at the same time now,” says Austin Graves, Ph.D., instructor of neuroscience at the Johns Hopkin University School of Medicine.<\/p>\n

The space between brain cells, or neurons, is incredibly tiny. It\u2019s less than a micron \u2013 about a tenth of the width of a human hair. Within these junctions between neurons is a highway of passing molecules and proteins \u2013 mainly sodium and calcium \u2013 transferring from one neuron to the next.<\/p>\n

When neurotransmitters pass across a synapse and land on a neuron, they activate an AMPA glutamate receptor \u2013 a protein in the neuron\u2019s outer covering. \u201cThese receptors are the functional machinery of language between neurons,\u201d says Graves.<\/p>\n

Huganir and other scientists have shown that synapses and the receptors embedded in them are key locations for learning in the brain. It\u2019s where memories are encoded, they say.<\/p>\n

To study how synapses operate, scientists customarily culture samples of brain cells in the laboratory to screen for increases or decreases in proteins made by the cells. They also examine subsets of neurons in various regions of the brain, but scientists had not previously been able to image synapses in the entire brain on this scale, say the researchers.<\/p>\n

For the research, the scientists genetically engineered mice by inserting the GRIA1 gene into the DNA, producing a green glowing tag on all AMPA glutamate proteins. When neurons amp up their signalling, they produce more AMPA glutamate proteins, and the green signal gets brighter. Since AMPA glutamate receptors are very common, the researchers were able to pinpoint nearly all excitatory neurons \u2013 which are more likely to send signals to other neurons instead of block them \u2013 in the mouse brain. Then, the researchers tweaked a whisker on each mouse and used high powered micro-scopes to track which synapses glowed green and the brightness of the signal. They found about 600,000 glowing synapses and indications that the brightness of the green signal corresponded to the strength of the AMPA glutamate receptor\u2019s response.<\/p>\n

Huganir says the new system generates mindboggling amounts of data. So, the researchers worked with computational scientists in the Johns Hopkins Department of Biomedical Engineering to develop artificial intelligence and machine learning techniques to train and validate algorithms that auto-matically detect all of the glowing synapses and how they change over time with experience and learning.<\/p>\n

Their current work is a proof-of-principle study that shows the capabilities of this synaptic imaging tool, say the researchers.<\/p>\n

The researchers also plan to use the tool to study other mouse behaviours, learning and memory, and to examine how synapses change under certain conditions, such as ageing, Alzheimer\u2019s Disease and autism.<\/p>\n<\/div><\/section>
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Every green glowing area is one synapse in a living mouse\u2019s brain. This video screenshot shows dense constellations of millions of synapses throughout the mouse cortex. Credit: Austin Graves, Johns Hopkins Medicine<\/p>\n<\/div><\/div><\/div>\"\"<\/div><\/div><\/div>
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