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Imaging the sleeping brain
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News & Comment
TRENDS in Neurosciences Vol.24 No.3 March 2001
In Brief
Imaging the sleeping brain In the December issue of Neuron, a research group at the Institute of Neurology, UK, has reported that a human sleeping brain can be influenced by external auditory stimuli in a stimulus-specific manner. Using fMRI images, researchers found that saying the participant’s name evoked a greater activation compared with a generic beep in orbitofrontal regions and the amygdaloid complex in both awake and sleep states. Amazingly, the activation in response to the name stimulus was greatest during nonREM sleep, when these regions are normally deactivated. This suggests that during sleep, important external information can reactivate neural circuits to a higher level compared with that achieved when awake. The implications of this study extend beyond sleep research and auditory processing to touch upon issues of consciousness in normal and altered states.
instituted so President-elect George W. Bush set a new budget. When disagreements had delayed the approval past election day, Congress passed several temporary funding bills to sustain operations in the interim. Under the new budget, both the National Institute of Neurological Disorders and Stroke and the National Institute of Mental Health are expected to receive over a billion dollars each. Additionally, $47 million dollars was requested to construct a new National Neuroscience Research Center that would foster collaboration among the different NIH institutes that support neuroscience research. This center would receive a total of $73 million over two years.
might also have therapeutic potential because other Na+ channel blockers have been used as painkillers and anti-epileptics.
New neurotoxin reported in blue-green algae
In a retrospective, case-control study reported in the December 20 J. Am. Med. Assoc. no association was found between cellular phone use and temporal lobe tumors. Furthermore, in patients with brain cancers, there was no association between handedness and tumor location. Using phone bills and questionnaires to interview individuals with and without brain cancer about their cellular phone use between 1994 and 1998, no significant differences were found between the two groups regarding either the number of months the phone was used or the number of hours of use each month. This is good news not only for cellular phone users, but also the cellular phone industry, which is facing billions of dollars in lawsuits. The study is limited, however, to adults using analog services for an average of only two to three hours a month for a period of two to three years. Longer-term health effects in more frequent and younger users still needs to be investigated.
Drosophila axonal pathfinding Researchers have uncovered intricate axonal pathfinding mechanisms involving attraction, repulsion, and concentration gradients in developing fruit flies. Proteins called netrins initally attract the axons toward the midline, but after the axons cross the midline they begin to express a receptor protein, roundabout (or robo) for the repellant protein, ‘slit.’ This insures axons do not cross back over the midline before finding appropriate axon bundles to travel with. Now, with the report of two new additional receptors, robo2 and robo3, researchers show that the more robo receptor types the axon expresses, the further from the midline it travels. Axons expressing only robo1 choose a path very near and parallel to the center line, whereas axons expressing all three receptors travel the furthest away to areas of lower slit concentration. The complete studies were published by two separate research teams in four papers in the December issues of Cell and Neuron.
NIH budget approved In December, the United States Congress approved a 14.2% increase for the National Institutes of Health (NIH). This raises the NIH budget to $20.3 billion. The approval abolished concerns that a freeze would be
A neurotoxin that is novel in structure and potency and which acts at voltage-gated Na+ channels, was reported at the 2000 International Chemical Congress of Pacific Basin Societies, which is comprised of the national chemical societies in the United States, Australia, Canada, Japan and New Zealand. The toxin was extracted from the marine cyanobacteria Lyngbya majuscula, the blue-green algae commonly known as ‘pond scum,’ in the Caribbean island of Curacao. It has been named ‘kalkitoxin’ in honor of the islands Kalki Bay in which it was found. The lethal toxin targets Na+ channels in brine shrimp and prevents nerves cells from generating and propagating action potentials. Known toxins have been instrumental in teaching neuroscientists how these channels work and kalkitoxin, which is structurally unrelated to these toxins, may reveal additional insights. The compound
No link between cellular phone use and brain cancer
Neural network challenge solved In a novel attempt to stimulate neuroscientists to think about how the brain handles pattern-recognition tasks, researchers at Princeton and New York Universities developed an intellectual contest. They created an artificial organism based on simple properties of brain function and encouraged scientists to investigate how this ‘silicon mouse’ recognizes the word ‘one.’ The challenge was to deduce the principles operating this network from ‘experimental’ observations, or reconstruct
http://tins.trends.com 0166-2236/01/$ – see front matter © 2001 Elsevier Science Ltd. All rights reserved.
News & Comment
TRENDS in Neurosciences Vol.24 No.3 March 2001
In Brief
Imaging the sleeping brain In the December issue of Neuron, a research group at the Institute of Neurology, UK, has reported that a human sleeping brain can be influenced by external auditory stimuli in a stimulus-specific manner. Using fMRI images, researchers found that saying the participant’s name evoked a greater activation compared with a generic beep in orbitofrontal regions and the amygdaloid complex in both awake and sleep states. Amazingly, the activation in response to the name stimulus was greatest during nonREM sleep, when these regions are normally deactivated. This suggests that during sleep, important external information can reactivate neural circuits to a higher level compared with that achieved when awake. The implications of this study extend beyond sleep research and auditory processing to touch upon issues of consciousness in normal and altered states.
instituted so President-elect George W. Bush set a new budget. When disagreements had delayed the approval past election day, Congress passed several temporary funding bills to sustain operations in the interim. Under the new budget, both the National Institute of Neurological Disorders and Stroke and the National Institute of Mental Health are expected to receive over a billion dollars each. Additionally, $47 million dollars was requested to construct a new National Neuroscience Research Center that would foster collaboration among the different NIH institutes that support neuroscience research. This center would receive a total of $73 million over two years.
might also have therapeutic potential because other Na+ channel blockers have been used as painkillers and anti-epileptics.
New neurotoxin reported in blue-green algae
In a retrospective, case-control study reported in the December 20 J. Am. Med. Assoc. no association was found between cellular phone use and temporal lobe tumors. Furthermore, in patients with brain cancers, there was no association between handedness and tumor location. Using phone bills and questionnaires to interview individuals with and without brain cancer about their cellular phone use between 1994 and 1998, no significant differences were found between the two groups regarding either the number of months the phone was used or the number of hours of use each month. This is good news not only for cellular phone users, but also the cellular phone industry, which is facing billions of dollars in lawsuits. The study is limited, however, to adults using analog services for an average of only two to three hours a month for a period of two to three years. Longer-term health effects in more frequent and younger users still needs to be investigated.
Drosophila axonal pathfinding Researchers have uncovered intricate axonal pathfinding mechanisms involving attraction, repulsion, and concentration gradients in developing fruit flies. Proteins called netrins initally attract the axons toward the midline, but after the axons cross the midline they begin to express a receptor protein, roundabout (or robo) for the repellant protein, ‘slit.’ This insures axons do not cross back over the midline before finding appropriate axon bundles to travel with. Now, with the report of two new additional receptors, robo2 and robo3, researchers show that the more robo receptor types the axon expresses, the further from the midline it travels. Axons expressing only robo1 choose a path very near and parallel to the center line, whereas axons expressing all three receptors travel the furthest away to areas of lower slit concentration. The complete studies were published by two separate research teams in four papers in the December issues of Cell and Neuron.
NIH budget approved In December, the United States Congress approved a 14.2% increase for the National Institutes of Health (NIH). This raises the NIH budget to $20.3 billion. The approval abolished concerns that a freeze would be
A neurotoxin that is novel in structure and potency and which acts at voltage-gated Na+ channels, was reported at the 2000 International Chemical Congress of Pacific Basin Societies, which is comprised of the national chemical societies in the United States, Australia, Canada, Japan and New Zealand. The toxin was extracted from the marine cyanobacteria Lyngbya majuscula, the blue-green algae commonly known as ‘pond scum,’ in the Caribbean island of Curacao. It has been named ‘kalkitoxin’ in honor of the islands Kalki Bay in which it was found. The lethal toxin targets Na+ channels in brine shrimp and prevents nerves cells from generating and propagating action potentials. Known toxins have been instrumental in teaching neuroscientists how these channels work and kalkitoxin, which is structurally unrelated to these toxins, may reveal additional insights. The compound
No link between cellular phone use and brain cancer
Neural network challenge solved In a novel attempt to stimulate neuroscientists to think about how the brain handles pattern-recognition tasks, researchers at Princeton and New York Universities developed an intellectual contest. They created an artificial organism based on simple properties of brain function and encouraged scientists to investigate how this ‘silicon mouse’ recognizes the word ‘one.’ The challenge was to deduce the principles operating this network from ‘experimental’ observations, or reconstruct
http://tins.trends.com 0166-2236/01/$ – see front matter © 2001 Elsevier Science Ltd. All rights reserved.