Cell mediated immunity:
This video gives a brief overview of the how cell mediated immunity in the body is activated, and the processes that occur once it happens. Cell mediated immunity is the branch of the immune system that involves lymphocytes (B and T cells). T cells are involved in the recognition and destruction of infected cells whereas B cells mature into plasma or memory cells and are involved in the production of antibodies.
Why You Forget: 5 Strange Facts About Memory
Memory can be a playful thing. It collects minute details from childhood events, yet leaves us wondering where we left our keys.
There are several types of memories, and the brain has a unique way of forgetting each kind. Psychologists have classified various ways by which we forget, and biologists have studied forgetting mechanisms at the cellular level.
"To make this journey we’ll need imagination, but imagination alone is not enough because the reality of nature is far more wondrous than anything we can imagine."
- Neil deGrasse Tyson, Cosmos
Harvard neuroscientists have made a discovery that turns 160 years of neuroanatomy on its head.
Myelin, the electrical insulating material in the body long known to be essential for the fast transmission of impulses along the axons of nerve cells, is not as ubiquitous as thought, according to new work led by Professor Paola Arlotta of the Harvard Stem Cell Institute (HSCI) and the University’s Department of Stem Cell and Regenerative Biology, in collaboration with Professor Jeff Lichtman of Harvard’s Department of Molecular and Cellular Biology.
“Myelin is a relatively recent invention during evolution,” says Arlotta. “It’s thought that myelin allowed the brain to communicate really fast to the far reaches of the body, and that it has endowed the brain with the capacity to compute higher-level functions.”
In fact, loss of myelin is a feature in a number of devastating diseases, including multiple sclerosis and schizophrenia.
But the new research shows that despite myelin’s essential roles in the brain, “some of the most evolved, most complex neurons of the nervous system have less myelin than older, more ancestral ones,” said Arlotta, co-director of the HSCI neuroscience program.
What this means, she said, is that the higher one looks in the cerebral cortex — closer to the top of the brain, which is its most evolved part — the less myelin one finds. Not only that, but “neurons in this part of the brain display a brand-new way of positioning myelin along their axons that has not been previously seen. They have ‘intermittent myelin’ with long axon tracts that lack myelin interspersed among myelin-rich segments.”
“Contrary to the common assumptions that neurons use a universal profile of myelin distribution on their axons, the work indicates that different neurons choose to myelinate their axons differently,” Arlotta said. “In classic neurobiology textbooks, myelin is represented on axons as a sequence of myelinated segments separated by very short nodes that lack myelin. This distribution of myelin was tacitly assumed to be always the same, on every neuron, from the beginning to the end of the axon. This new work finds this not to be the case.”
The results of the research by Arlotta and postdoctoral fellow Giulio Srubek Tomassy, the first author on the report, are published in the latest edition of the journal Science.
The paper is accompanied by a “perspective” by R. Douglas Fields of the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health, who said that Arlotta and Tomassy’s findings raise important questions about the purpose of myelin, and “are likely to spark new concepts about how information is transmitted and integrated in the brain.”
Arlotta and Tomassy collaborated closely on the new work with postdoctoral fellow Daniel Berger of the Lichtman lab, which generated one of the two massive electron microscopy databases that made the work possible.
“The fact that it is the most evolved neurons, the ones that have expanded dramatically in humans, suggest that what we’re seeing might be the ‘future.’ As neuronal diversity increases and the brain needs to process more and more complex information, neurons change the way they use myelin to achieve more,” said Arlotta.
Tomassy said it is possible that these profiles of myelination “may be giving neurons an opportunity to branch out and ‘talk’ to neighboring neurons.” For example, because axons cannot make synaptic contacts when they are myelinated, one possibility is that these long myelin gaps may be needed to increase neuronal communication and synchronize responses across different neurons. He and Arlotta postulate that the intermittent myelin may be intended to fine-tune the electrical impulses traveling along the axons, in order to allow the emergence of highly complex neuronal behaviors.
Drugs impact every organ in the body. In this easy to read graphic, we demonstrate the impact of the most commonly abused drugs on the body’s organs and its systems.
Many people who use drugs, even if they are prescribed, are unaware of how a drug impacts the normal functioning of the body. Whether it is tranquilizers, steroids, or marijuana you can see the organs affected and read about the drug induced changes that occur within each of the body’s systems.
Some people need both their hearts and their heads examined.
(Thanks to Progressive America for the graphic)
Does having a baby hurt more than getting kicked in the testicles?
Cristen looks for a scientific answer to one of life’s most persistent questions about men, women and pain tolerance.
Happy Medical Laboratory Professionals Week!
Medical Laboratory Professionals Week (MLPW) is taking place April 20-26, 2014. MLPW provides the profession with a unique opportunity to increase public understanding of and appreciation for clinical laboratory personnel. Read about fun ideas to celebrate.
Visit the official MLPW store to purchase promotional items to help celebrate and promote the week. Many laboratorians wear buttons or t-shirts with the official logo during the celebratory week to increase others’ awareness.
Read more: http://www.laboratoryequipment.com/news/2014/04/happy-medical-laboratory-professionals-week
Owls confirmed to be the creepiest birds ever. LOOK AT THE FUCKING THINGS. If you fail to notice the one on the left fucking SWALLOWING a rat, then you have the dude singing some satanic chant or something next to him, and then you have those two other fucking psychos synchronized to make you feel creeped the fuck out with their soulless dance of FUCKING DOOM.
I really am tempted to reblog this every time it’s on my dash. That description is one of the best things on the internet.
i need one of these please.
I love when cats decide they love something.
That is a very patient bunny.
Mark Wahlberg’s got one. Do you?
The Chance To Dance Again
by Michael Keller
We highlighted the TED talk of Hugh Herr a couple of weeks ago. But his work is too important and beautiful to leave to just one post.
The MIT associate professor of media arts and sciences is making prosthetic limbs and exoskeletons that restore function in those who have lost legs from injury or disease. This set of gifs focuses on his team’s BiOM powered ankle and foot prosthesis.
"Bionics is not only about making people stronger and faster," he said during the talk. "Our expression, our humanity can be embedded into electromechanics."
To prove his point, Herr and fellow researchers studied dance movement to replace the lower leg that professional dancer Adrianne Haslet-Davis lost after last year’s Boston marathon bombing. He concluded his talk by bringing Haslet-Davis on the stage to perform a bionic rumba.