While nicotine is highly addictive, researchers have also shown the drug to enhance learning and memory - a property that has launched efforts to develop nicotine-like drugs to treat cognitive deficits in Alzheimer's and Parkinson's diseases, schizophrenia, and attention-deficit/hyperactivity disorder.
A key problem in designing such drugs has been that little was known about the detailed mechanism by which nicotine exerts its learning-enhancing effects.
Now, researchers have discovered important details of how nicotine adjusts the signaling properties of neuronal wiring to enhance memory. Such signaling properties include the strength of the connections by which one neuron triggers another. Huibert Mansvelder and colleagues reported their findings in the April 5, 2007, issue of the journal Neuron, published by Cell Press.
Scientists know that information travels between brain cells along hairlike extensions called axons. For the first time, researchers have found that axons don't just transmit information - they can turn the signal up or down with the right stimulation.
This finding may help scientists develop treatments for psychiatric disorders such as depression and schizophrenia in which it is thought that different parts of the brain do not communicate correctly with each other.
"Until now, scientists have thought that in the brain's cortex -- where most cognitive processes occur -- information was only processed in the cell body," said Raju Metherate, author of the study, associate professor of neurobiology and behavior, and director of the Center for Hearing Research at UC Irvine. "The result of our study suggests that we must consider the axons as sites of information processing - and of potential problems when things go wrong."
This study appears online Aug. 19 in Nature Neuroscience.
Roger Highfield Telegraph Mon, 20 Aug 2007 10:18 UTC
The one third of our lives that we spend asleep is an enigma to scientists. They still don't even clearly understand why we have to sleep.
But perhaps the greatest puzzle of all is the role of dreaming, which great thinkers have puzzled over for millennia.
To the ancients, dreams led to divine inspiration; Aristotle held that in dreams the sleeper saw things that he wished or intended to do, while Thomas Nashe, the 16th-century pamphleteer, wrote them off as "a bubbly scum or froth of the fancy which the day hath left undigested".
Roger Highfield Telegraph Mon, 20 Aug 2007 10:05 UTC
Dark-coloured fruits and vegetables may help to protect against colon cancer, research has shown.
Scientists found that the chemicals that give foods such as grapes, radishes, purple carrots and bilberries their colour significantly slow the growth of colon cancer cells.
Evidence from experiments on rats and on human colon cancer cells suggests that anthocyanins, the compounds that colour most red, purple and blue fruits and vegetables, slow the growth of the cells by anything from 50 to 80 per cent.
Male circumcision could prevent millions of HIV infections every year and play a major role in controlling the virus' spread in developing nations, a major AIDS conference was told Tuesday.
Comment: The logic behind this is almost incomprehensible. Why stop there? Why not cut off women's breasts to prevent breast cancer? Remove a lung to cut lung cancer by 50%. The absurdities are boundless.
"It is important that, while circumcision interventions are being planned, several points must be considered carefully. If the experiment fails, Africans are likely to feel abused and exploited by scientists who recommended the circumcision policy. In a region highly sensitive to previous colonial exploitation and suspicious of the biological warfare origin of the virus, failure of circumcision is likely to be a big issue. Those recommending it should know how to handle the political implications." - James P.M. Ntozi
President Bush's $15 billion anti-AIDS program will begin investing significant money in making circumcision available to African men seeking to protect themselves from HIV, top U.S. health officials said Sunday.
Recent research showing that circumcision dramatically cuts the rate of HIV infection is highly convincing, a delegation of U.S. officials, led by Health and Human Services Secretary Mike Leavitt, told reporters in Johannesburg.
Last week on Friday, August 12th, 2007, CNBC's Erin Burnett made some very appalling statements. In an interview with Chris Matthews on MSNBC's Hardball Burnett claimed that playing with lead toys and eating poison-tainted food is a good price to pay for paying cheaper prices at Wal-Mart. Here are Burnett's exact quotes:
"A lot of people like to say, uh, scaremonger about China, right? A lot of politicians, and I know you talk about that issue all the time. I think people should be careful what they wish for on China. Ya know, if China were to revalue it's currency or China is to start making say, toys that don't have lead in them or food that isn't poisonous, their costs of production are going to go up and that means prices at Wal-Mart here in the United States are going to go up too. So, I would say China is our greatest friend right now, they're keeping prices low and they're keeping the prices for mortgages low, too."
Several samples of mites trapped over recent days in northern Illinois were sent to Nebraska for identification, state health officials said Thursday, spurring hopes the culprit behind a mysterious outbreak of rashes will be caught at last.
Older white men who are better able to cope with stress experience higher levels of so-called "good cholesterol" than men who are more hostile or socially isolated, according to a study released at the 115th Annual Convention of the American Psychological Association.
But that same coping ability had no effect on the subjects' "bad cholesterol" levels, the research found.
Researchers gathered data from 716 men who participated in the Normative Aging Study to look at the complex interrelations among hostility, stress and coping processes and cholesterol levels. The average age in the sample was 65. Most of the men were white and were evenly split between white-collar and blue-collar occupations.