super science sunday
Cats make you crAzy, well sort of...
Toxoplasma gondii is a common parasite found in the guts of cats; it sheds eggs that are picked up by rats and other animals that are eaten by cats. Toxoplasma forms cysts in the bodies of the intermediate rat hosts, including in the brain. Dr. E. Fuller Torrey (Associate Director for Laboratory Research at the Stanley Medical Research Institute) noticed links between Toxoplasma and schizophrenia in human beings, approximately three billion of whom are infected with T. gondii:
* Toxoplasma infection is associated with damage to astrocytes, glial cells which surround and support neurons. Schizophrenia is also associated with damage to astrocytes.
* Pregnant women with high levels of antibodies to Toxoplasma are more likely to give birth to children who will develop schizophrenia.
* Human cells raised in petri dishes, and infected with Toxoplasma, will respond to drugs like haloperidol; the growth of the parasite stops. Haloperidol is an antipsychotic, used to treat schizophrenia.
Miltary science is dazzling
Not a week goes by when David Law, science and technology chief for the Joint Non-Lethal Weapons Directorate, doesn’t receive a call from Pentagon brass asking for devices to warn civilians to stop at vehicle checkpoints. At checkpoints, soldiers can only wave their arms and shout at approaching vehicles beyond 100 meters. If the car continues to approach, the soldiers must open fire, Law said. “We know we can do better,” he added. Law believes the solution is a laser dazzler, a beam of light designed to flash in a driver’s eyes more than 100 meters away from a checkpoint or convoy without causing temporary or permanent blindness.The laser dazzler’s purpose is to “get the driver to do something. Pull off his foot or veer away … so the driver realizes he’s being warned,” Law said.
The goal is not to take away the driver’s vision, because that may result in an out-of-control vehicle barreling down on the soldiers’ position, he added. “We’re not trying to kill, maim and certainly not to blind. We’re trying to warn.” The laser dazzlers being tested meet all safety levels, Law added. A sonic weapon the directorate tested cracked windshields, he noted, which could cause a safety hazard as well.
Bullying alters the mind
Mice bullied by other mice show mental and genetic changes, that scientists say that might give us insight into psychiatric disorders. The results reveal neural mechanisms by which social learning is shaped by psychosocial experience and how antidepressants act in this particular brain circuit. They also suggest new strategies for treating mood disorders such as depression, social phobia and post-traumatic stress disorder, in which social withdrawal is a prominent symptom. Coursing from a hub in the center of the brain (ventral tegmental area), the relevant circuit mediates responses to emotionally important environmental stimuli via release of dopamine. Activity of this neurotransmitter is regulated in the circuit by brain derived neurotrophic factor (BDNF), which is known to play a key role in memory. Drs. Olivier Berton and Eric Nestler, University of Texas Southwestern Medical Center (UTSMC), and colleagues, report on their study in the February 10, 2005 issue of Science. He and his colleagues also discovered that social defeat triggered an upheaval in gene expression in the target area of the circuit, the nucleus accumbens, located deep in the front part of the brain -- 309 genes increased in expression while 17 decreased.
Toxoplasma gondii is a common parasite found in the guts of cats; it sheds eggs that are picked up by rats and other animals that are eaten by cats. Toxoplasma forms cysts in the bodies of the intermediate rat hosts, including in the brain. Dr. E. Fuller Torrey (Associate Director for Laboratory Research at the Stanley Medical Research Institute) noticed links between Toxoplasma and schizophrenia in human beings, approximately three billion of whom are infected with T. gondii:
* Toxoplasma infection is associated with damage to astrocytes, glial cells which surround and support neurons. Schizophrenia is also associated with damage to astrocytes.
* Pregnant women with high levels of antibodies to Toxoplasma are more likely to give birth to children who will develop schizophrenia.
* Human cells raised in petri dishes, and infected with Toxoplasma, will respond to drugs like haloperidol; the growth of the parasite stops. Haloperidol is an antipsychotic, used to treat schizophrenia.
Miltary science is dazzling
Not a week goes by when David Law, science and technology chief for the Joint Non-Lethal Weapons Directorate, doesn’t receive a call from Pentagon brass asking for devices to warn civilians to stop at vehicle checkpoints. At checkpoints, soldiers can only wave their arms and shout at approaching vehicles beyond 100 meters. If the car continues to approach, the soldiers must open fire, Law said. “We know we can do better,” he added. Law believes the solution is a laser dazzler, a beam of light designed to flash in a driver’s eyes more than 100 meters away from a checkpoint or convoy without causing temporary or permanent blindness.The laser dazzler’s purpose is to “get the driver to do something. Pull off his foot or veer away … so the driver realizes he’s being warned,” Law said.
The goal is not to take away the driver’s vision, because that may result in an out-of-control vehicle barreling down on the soldiers’ position, he added. “We’re not trying to kill, maim and certainly not to blind. We’re trying to warn.” The laser dazzlers being tested meet all safety levels, Law added. A sonic weapon the directorate tested cracked windshields, he noted, which could cause a safety hazard as well.
Bullying alters the mind
Mice bullied by other mice show mental and genetic changes, that scientists say that might give us insight into psychiatric disorders. The results reveal neural mechanisms by which social learning is shaped by psychosocial experience and how antidepressants act in this particular brain circuit. They also suggest new strategies for treating mood disorders such as depression, social phobia and post-traumatic stress disorder, in which social withdrawal is a prominent symptom. Coursing from a hub in the center of the brain (ventral tegmental area), the relevant circuit mediates responses to emotionally important environmental stimuli via release of dopamine. Activity of this neurotransmitter is regulated in the circuit by brain derived neurotrophic factor (BDNF), which is known to play a key role in memory. Drs. Olivier Berton and Eric Nestler, University of Texas Southwestern Medical Center (UTSMC), and colleagues, report on their study in the February 10, 2005 issue of Science. He and his colleagues also discovered that social defeat triggered an upheaval in gene expression in the target area of the circuit, the nucleus accumbens, located deep in the front part of the brain -- 309 genes increased in expression while 17 decreased.