Dose of sugar may make you smarter

Studies have shown that children perform better if they eat breakfast. Dr. Paul Gold, a psychologist at the University of Virginia found in his studies on rats and humans that subjects that were given a dose of glucose sugar could think better. In one test, Gold's human subjects drank lemonade sweetened with either glucose sugar or saccharin. They then heard a short story and were later asked what they remembered of the story. Results revealed that people given glucose sugar tended to recall more. According to Gold, glucose seemed to enhance memory even among people with cognitive disabilities like Alzheimer¹s disease.

SOURCE: Carolyn O'Neil, Fitness and Health. The Brain Stories

Estrogen May Protects Cognition

Some sex hormones appear to be important for cognition. Studies in rats and monkeys have found an association between high blood levels of estrogen and performance on various cognitive tasks. A previous study of women with mild Alzheimer's disease showed that estrogen therapy improved verbal memory and attention; the effect disappeared when estrogen was discontinued. Several large studies have found an association between increased estrogen levels and diminished risk for developing Alzheimer's: One of these recently estimated that taking estrogen for more than a year reduces the risk by up to 5 percent annually.

Science 1997 May 2; 276:675-678

Suicide is linked to neurotransmitters

New studies indicate that people who commit suicide have not enough serotonin, a brain chemical that controls mood.

Serotonin normally helps people restrain their impulses. Without enough of the chemical, they may act on their suicidal thoughts.

This shows that psychiatric illnesses and suicide are brain-related disorders, researchers say.

In Washington, at a workshop on suicide research, scientists said they have pinpointed an area near the front of the brain where the biochemical activity seems to go awry in people who commit suicide.

Now, through techniques like this, scientists are trying to see if they can detect the same abnormality in the brains of people who are alive.

SOURCE: Fitness and Health. The Brain Stories

Why Some Memories Are So Vivid ?

Studies say that emotional experiences may help cement memories into the brain, which might explain why some recollections are so vivid. Memories are saved on different levels, with some staying in the brain for only a few seconds, others retrievable with some effort, while others are almost permanent.

"Rehearsal" of information can help strengthen the connections between neurons, or brain cells. It is the pattern of connections between neurons that forms the physical basis of memories.

Proteins are required to make the connections - and thus memories stick, but scientists were unsure whether the brain actually aimed the proteins at each individual recollection.

If an animal was feeling intense emotions during a significant experience, memories that would ordinarily be dropped were cemented in with the central recollection.

SOURCE: Fitness and Health. The Brain Stories

Sex Differences in Brain Neurotransmitter Involved in Depression

Medical researchers at the Montreal Neurological Institute (Canada) have reported that there is a significant difference in the rate of synthesis of serotonin in the brain of men and women. Serotonin is a neurotransmitter (chemical released between the brain cells to permit the transmission of impulses between them) associated with the cerebral basis of emotions. Severe depressed people have a lower level of serotonin than normals, as shown by PET scans of their brains. Although normal persons of both sexes have approximately the same level of serotonin, menís brains synthesize it 52 % faster than womenís. This difference may be the explanation for the finding that women are more than two times more prone to depression than men. The researchers also compared the response of brain serotonin to emotional stress in men and women. The impact of stress was four times larger in men than in women.

Proc Natl Acad Sci U S A 94(10), 5308-5313 (1997)

Grafts of Pig Nerve Cells for the Treatment of Parkinsonís Disease

The successful transplantation of pig nerve cells into a human brain is the new weapon of medical research against Parkinsonís disease, a nervous disease characterized by tremor, rigidity and other disabling signs.This disease is caused by a loss of nerve cells in the basal ganglia, a part of the brain responsible for the control and coordination of movement. Previous works had shown that the surgical implantation of human fetal tissue into this part of the brain may reactivate the lost functions and decrease Parkinsonís symptoms, but this procedure has remained controversial due to anti-abortion issues. Researchers from Massachusetts reported that nerve cells from the fetus of a pig had survived more than 6 months in the brain of a 60-year-old Parkinsonís patient; opening the way for the use of brain transplantations of other species.

Nature Medicine, Volume 3 Number 5 - May 1997, p. 474

Excessive Daytime Sleepiness Related to Inflammatory Proteins

Cytokines, proteins associated with inflammation in our organism, may be related to excessive daytime sleepiness and fatigue, particularly in obese patients, a new study has shown. Researchers already knew that giving interleukin-6 (IL-6) for the treatment of cancer increased these symptoms, so physicians of the National Institute of Child Health and Human Development, USA, screened 31 patients with excessive daytime sleepiness for abnormally higher levels of IL-6 and TNF-alpha, another cytokine. Some of these patients had diagnosed sleep abnormalities, such as sleep apnea and narcolepsy. The subjects had either TNF-alpha, or IL-6, or both in elevated levels. Obese patients had altered levels of IL-6, while patients with nighttime sleep disturbances had more altered levels of TNF-alpha. Other researchers have reported that "sleeping sickness" - a parasitic infection spread by the bite of the African tse-tse fly, is also associated to high levels of both cytokines. These discoveries might open the way for new drugs that will counterbalance the higher levels of cytokines, thus decreasing sleepiness and fatigue.

SOURCE: Journal of Clinical Endocrinology and Metabolism (1997;82:1313-1316) May 20, 1997

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