Through experiments on stained neurons, the research team \u2013 under the leadership of Martin Hallbeck, associate professor of Pathology \u2013 has been able to depict the process of neurons being invaded by diseased proteins that are then passed on to nearby cells.<\/p>\n \u201cThe spread of Alzheimer\u2019s, which can be studied in the brains of diseased patients, always follows the same pattern. But until now how and why this happens has not been understood,\u201d says Hallbeck, who along with his research group has now published their results in The Journal of Neuroscience<\/em>.<\/p>\n The illness starts in the entorhinal cortex \u2013 a part of the cerebral cortex, and then spreads to the hippocampus.<\/strong> Both of these areas are important for memory. Gradually, pathological changes take place in more and more areas of the brain, while the patient becomes even sicker.<\/p>\n Two proteins have been identified in connection with Alzheimer\u2019s: beta amyloid and tau<\/strong>. Normally tau is found in the axons \u2013 the outgrowths that connect between neurons \u2013 where it has a stabilising function, while beta amyloid seems to have a role in the synapses where the neurons transfer signal substances to each other. But in Alzheimer\u2019s patients, something happens with these proteins; autopsies reveal abnormal accumulations of both.<\/p>\n Why they become abnormal is still unknown, but what is known is that it\u2019s not the large accumulations, or plaques, that damage the neurons. Instead, smaller groups of beta amyloid \u2013 called oligomeres \u2013 seem to be the toxic form that gradually destroy the neurons and shrink the brain.<\/p>\n \u201cWe wanted to investigate whether these oligomeres can spread from neuron to neuron, something many researchers tried earlier but didn\u2019t succeed,\u201d Hallbeck says.<\/p>\n The study was inaugurated with an experiment on neuron cultures, where researchers injected oligomeres stained with a phosphorescent red substance called TMR using a very thin needle. The next day the neighbouring, connected neurons were also red, which showed that the oligomeres had spread.<\/p>\n To test whether a sick neuron can \u201cinfect\u201d others, they conducted a round of experiments with mature human neurons stained green and mixed with others that were red after having taken up stained oligomeres. After a day, approximately half of the green cells had been in contact with a few of the red ones. After two more days, the axons had lost their shape and organelles in the cell nucleus had started to leak.<\/p>\n \u201cGradually more and more of the green cells became sick. Those that hadn\u2019t taken up the oligomeres, on the other hand, weren\u2019t affected<\/strong>,\u201d Hallbeck says.<\/p>\n The study is a breakthrough in understanding Alzheimer\u2019s and its progress. If a way of stopping the transfer can be found, it could lead to a more effective inhibitor against the disease.<\/p>\n Article:<\/strong> Spreading of neurodegenerative pathology via neuron-to-neuron transmission of beta-amyloid by Sangeeta Nath, Lotta Agholme, Firoz Kurudenkandy, Bj\u00f6rn Granseth, Jan Marcusson and Martin Hallbeck. The Journal of Neuroscience<\/em>, 27 June 2012.<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":" From the Link\u00f6ping University press release via ScienceDaily: The inexorable spread of Alzheimer\u2019s disease through the brain leaves dead neurons and forgotten thoughts in its wake. Researchers at Link\u00f6ping University… Read more »<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[10,4,6],"tags":[195,42,18,194,49],"_links":{"self":[{"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/posts\/4242"}],"collection":[{"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/comments?post=4242"}],"version-history":[{"count":2,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/posts\/4242\/revisions"}],"predecessor-version":[{"id":4250,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/posts\/4242\/revisions\/4250"}],"wp:attachment":[{"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/media?parent=4242"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/categories?post=4242"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/tags?post=4242"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"http:\/\/therapytoronto.ca\/images\/blogpics\/Brain4.jpg\" "\\"brain\\"")
The inexorable spread of Alzheimer\u2019s disease through the brain leaves dead neurons and forgotten thoughts in its wake. <\/strong>Researchers at Link\u00f6ping University in Sweden are the first to show how toxic proteins are transferred from neuron to neuron.<\/strong><\/p>\n