28 July 2015

Link Between Brain and Immune System

Research published this month reported a previously unknown line of communication between our brains and immune systems, adding to a fast-growing body of research suggesting that the brain and body are more connected than previously thought. The new work could have important implications for understanding and treating disorders of the brain. Outside tissue grafted into most parts of the body often results in immunologic attack; tissue grafted into the central nervous system on the other hand sparks a far less hostile response. Thanks in part to the blood-brain barrier — tightly packed cells lining the brain's vessels that let nutrients slip by, but, for the most part, keep out unwanted invaders like bacteria and viruses — the brain was long considered "immunologically privileged,” meaning it can tolerate the introduction of outside pathogens and tissues. The central nervous system was seen as existing separately from the peripheral immune system, left to wield its own less aggressive immune defenses. The brain’s privilege was also considered to be due to its lack of lymphatic drainage. The lymphatic system is our body's third and perhaps least considered set of vessels, the others being arteries and veins.

Lymphatic vessels return intracellular fluid to the bloodstream while lymph nodes – stationed periodically along the vessel network – serve has storehouses for immune cells. In most parts of the body, antigens – molecules on pathogens or foreign tissue that alert our immune system to potential threats – are presented to white blood cells in our the lymph nodes causing an immune response. But it was assumed that this doesn’t occur in the brain given its lack of a lymphatic network, which is why the new findings represent a dogmatic shift in understanding how the brain interacts with the immune system. Working primarily with mice, researchers at the University of Virginia identified a previously undetected network of lymphatic vessels in the meninges — the membranes that surround the brain and spinal cord — that shuttle fluid and immune cells from the cerebrospinal fluid to a group of lymph nodes in the neck, the deep cervical lymph nodes. By mounting whole mouse meninges and using neuroimaging the team noticed that T-cells were present in vessels separate from arteries and veins, confirming that the brain does in fact have a lymphatic system linking it directly the peripheral immune system.

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17 July 2015

How the Brain Feels the Hurt of Heartbreak

Everyone at one time or another, experienced negative social events that threaten our sense of social connection: divorce and breakups, exclusion from attractive groups, the deaths of loved ones. Interestingly, descriptions of these experiences borrow heavily from the language of physical pain. 

Research suggests that the reason these metaphors come so easily to us may be that social pain – the profound distress experienced when social ties are absent, threatened, damaged, or lost – is elaborated by the same neural and neurochemical substrates involved in processing physical pain.

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14 July 2015

Learning Impacts How Brain Processes Visualisation

In a University of California, a research team reports that in mouse models, the brain significantly changed its visual cortex operation modes by implementing top-down processes during learning. They found that when the mouse assigns a new meaning to a previously neutral visual stimulus, top-down control becomes much more influential in activating the visual cortex.  Top-down inputs interact with specific neuron types in the visual cortex to modulate its operation modes. This cognitive process uses our thoughts and influences our senses. For example, when we see a word with missing letters, our brain is able to fill in the blank based on past experiences.

Researchers looked at activity in excitatory neurons and somatostatin-expressing inhibitory neurons in the visual cortex and top-down inputs from the retrosplenial cortex (RSC) during associative learning to see how these affected the top-down and bottom-up processing—when perception begins with the senses. The findings indicate that intricate interactions of various circuit components effectively change the balance of top-down and bottom-up processing, with learning enhancing the contribution of top-down control. These results support the long-standing theory that the brain does not faithfully represent the environment but rather attempts to predict it based upon prior information.

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13 July 2015

Google Glass 2 Almost Ready For Volume Production

The future of Google Glass, the company’s much-maligned Internet-connected glasses, remains a mystery since the project was sent back to the drawing board earlier this year. But a new job listing on the company’s website hints that Google’s Glass efforts are moving forward and perhaps nearing the stage of volume production. Google’s Glass team is looking for an Advanced Technology Manufacturing Engineer, FATP. The FATP, the listing explains, stands for final assembly, test and pack. That sounds like the kind of role that’s necessary when a company has ambitions and plans for product that go beyond simple experimentation.

Google halted consumer sales of the $1,500 gadget in January amid waning interest from consumers and widespread privacy concerns related to the device’s built-in video camera. Google executive said at the time that it was time for a strategy reset. Glass was a no-show at last month’s Google I/O developer conference and the head of business for Glass is leaving the position, according to a recent report in Recode. There have been reports that a new version of Google Glass is being readied in partnership with Italian eyewear maker Luxottica. The Luxottica CEO said in April that Google Glass 2 is currently “in preparation” and suggested that Google is pondering a more radical change for version 3.0.

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11 July 2015

First Brain-to-Brain Interface

Imagine a future in which people with neurological disorders can tap into a healthy brain to re-learn how to move a paralyzed leg, or multiple brains are wired together to solve problems and control robots. This is something that is no longer beyond the realms of possibility. Scientists have shown that multiple animals can work together to solve problems through the power of thought alone for the first time, and the connotations could be huge. The work by researchers of Duke University in North Carolina involved two experiments: in the first, three rhesus macaque monkeys in separate rooms were wired together into a ‘brainet’ using implanted electrode arrays. They were then tasked with controlling a virtual avatar arm on a screen, but each monkey could only control the arm in two axes by thinking particular thoughts. Successfully moving the arm towards a target earned them a reward, juice, but this only worked when they all worked together. Over time, the monkeys improved and their brain activity became more strongly correlated, earning them more rewards.

In the second study, four rats were wired together and tasked with solving a set of computational problems to earn a prize, in this case water. One of the problems involved them predicting how likely it was to rain based on the temperature and pressure. Amazingly, they were able to correctly predict it 41% of the time – which the scientists said was better than random chance. One part of the research involved rhesus macaque monkeys controlling an avatar arm.  In this research, implants were needed to monitor the brain activity of more than 700 neurons in each of the animals, but the researchers hope that in future a non-invasive method could be used. This would open up entirely new avenues, particularly in humans. For example, neurologically disabled people could share a healthy brain and re-learn abilities that they may have lost, such as movement in a paralyzed limb. Or, organic computers could be made by linking brains together. The possibilities are certainly plentiful, but as this is the first attempt, it may take a while to see things come to fruition.

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