More genome race. I guess a 2 team contest is the most exciting - The Times certainly thinks so.
nytimes.com
October 26, 1999
Rivals Reach Milestones in Genome Race
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By NICHOLAS WADE
Two rival teams racing to decode the human genome have each neared or passed significant milestones.
It is hard to tell which team is ahead because they are pursuing the same goal along different paths. But both are apparently on track with ambitious schedules that call for "first drafts" of the genome to be completed next spring or summer.
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Government team: one chromosome pair decoded, 22 to go.
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The publicly financed consortium, a group of academic centers mainly in the United States and Britain, said last week that it had essentially decoded the first human chromosome, the 22d and smallest of the 23 pairs.
The decodable part of the chromosome is 33 million units of DNA, or about 1 percent of the entire genome, which is at least three billion units.
Also last week the consortium's rival, the Celera Corporation of Rockville, Md., said it had sequenced -- determined the order of the chemical letters -- in its first billion units of human DNA. But the sequenced lengths are in short fragments, and the harder part of the task is deciding how the fragments fit together.
The public consortium, financed principally by the National Institutes of Health in Bethesda, Md., and the Wellcome Trust of London, has been working on the human genome since 1990. It completed its pilot project, decoding the genome of the laboratory roundworm, in December.
Celera, headed by Dr. J. Craig Venter, jumped into the race only in May of last year. As a test of his high-risk strategy, Dr. Venter chose to decode the DNA of another standard laboratory organism, the Drosophila fruit fly, which he said will be completed by January.
At Celera's plant in Rockville, the finishing touches were being made last week to a futuristic control room that could be modeled on that of the starship Enterprise.
From an array of monitors, supervisors will control the 300 DNA sequencing machines, the robots that prepare fragments of DNA for analysis and a HAL-size computer that assembles the fragments into complete genomes and analyzes the Babel of genetic data.
In a nearby hall, a suite of DNA sequencing machines chorused in a deep-throated hum as they forced fragments of DNA through hair-fine tubes where electronic eyes read off the sequence of bases, as the four different units of DNA are known. In the computer room, a glitter of green lights signaled the arrival of the DNA sequence information through optic fiber switches.
"We are doing a billion bases every three and a half weeks," Dr. Venter said during a tour of the plant. Corporate responsibilities have forced him into the unusual costume of a suit and tie but not dulled his delight in the sophisticated machines at his disposal or the thrill of tackling a mountainous problem.
"We operate 24 hours a day, 7 days a week," he said. Asked why the hurry, he cited a need to file patent applications and quickly build a genetic database for clients.
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Having problems? Get in Synch with your Thalamus, buddy.
Seriously, a fascinating, simple theory of how the brain goes wrong in a variety of major illnesses.
nytimes.com
October 26, 1999
New Way of Looking at Diseases of the Brain
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By SANDRA BLAKESLEE
A highly respected neuroscientist has developed a provocative new theory of how the brain is organized which, if confirmed, would explain how and why the mind produces symptoms found in several seemingly unrelated disorders.
According to the theory, the deep sadness in severe depression, the hand wringing in obsessive compulsive disorder, the ringing in the ears of tinnitus, the unrelenting discomfort of chronic pain and the shaking and immobility seen Parkinson's disease all stem from the same basic brain defect: a decoupling of two brain regions that normally fire their cells in synchrony.
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The theory involves two brain areas -- the cerebral cortex and the thalamus -- and how they communicate.
The cortex is a thickly folded band of tissue that carries out higher mental capacities in humans and other mammals. It is composed of six layers of cells that are highly interconnected and organized into specialized regions that allow people to move their bodies, plan for the future, talk, listen, sense touch, respond to emotions and carry out other functions. The sixth layer of these cells is also directly connected through nerve fibers to cells in the thalamus, an older brain structure that is just under the cortex.
The thalamus is usually thought of as a relay station. Virtually all information flowing from the outside world and lower brain regions must go through the thalamus before being passed on to the cortex.
But according to Dr. Llinas, the thalamus does much more than simply pass information.
The way that it coordinates its activity with the cortex, he says, gives rise not only to the symptoms seen in many neurological and psychiatric diseases, but to consciousness itself.
It does so through what Dr. Llinas calls thalamo-cortical oscillations. The thalamus contains special cells that pass tiny electrical currents across their membranes in a highly coordinated manner, Dr. Llinas said in a telephone interview. Rather than firing sporadically and singly, like other nerve cells, the cells in the thalamus oscillate, firing in groups together at various frequencies.
By virtue of their connections, these thalamic cells then cause cells in layer six -- the layer of the cortex closest to them -- to oscillate at the same frequency. This coordination between these oscillating cells in the cortex and thalamus, which are constantly flipping signals back and forth, binds information from different regions of the brain into complete actions, perceptions, movements and into consciousness itself, he said.
When the cells oscillate at a high frequency, the brain is awake and alert.
When they fall into low frequencies, the brain becomes disconnected, unconscious and falls asleep.
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