Word: cortexes
(lookup in dictionary)
(lookup stats)
Dates: during 2000-2009
Sort By: most recent first
(reverse)
...powerful reminder that even the things about ourselves that we consider the most fundamental—our beliefs, our selves, and our basic conceptions of existence—are contingent facts, created by so much neurological circuitry. All it takes is a burst blood vessel in the cerebral cortex in order to completely alter our perception of reality...
...hippocampus begins to malfunction early in Alzheimer's disease. Imaging studies have shown that people with Alzheimer's typically have smaller than average hippocampi. Meanwhile, as the hippocampus is shrinking, the pathway between it and the prefrontal cortex also begins to degrade. Signals peter out and fade away, and questions take their place: Do I know you? Who am I? But it's not just with Alzheimer's: the hippocampus also goes at least somewhat awry in normal memory loss. "It's relatively stable in volume till about 60," Harvard neuroscientist Randy Buckner explains, "and then begins to change. People...
...Small's hunch--now proven--was that a node of the hippocampus different from the one affected in Alzheimer's was breaking down in normal memory loss. "In humans, monkeys and rats," he says, "normal aging targets a node called the dentate gyrus, while a different node--the entorhinal cortex--is relatively spared. But in Alzheimer's disease, it's almost exactly reversed." Small has gone deeper, pinpointing a protein molecule known as RbAp48 that is lower in the brains of people suffering ordinary age-related memory loss. He and his colleagues are now testing the effect of that molecule...
...even if you, like the mouse, are low in RbAp48, don't pin all the blame for your memory loss on your hippocampus. As people get older, their attention starts to flicker, and that plays a role of its own. The prefrontal cortex, which controls planning, organization, abstraction and forethought, is the same region that allows us to concentrate, and it starts to diminish in size well before middle age. It also begins to use the brain's fuel, glucose, less efficiently and loses about half the neurotransmitter dopamine it once had. The result of all this, says Amy Arnsten...
...Yale, Arnsten has roused idling monkey and rat brains with a medication called guanfacine, which appears to amplify the circuits of the prefrontal cortex. The drug has been tested on children with ADHD as well as on people with traumatic brain injury, posttraumatic stress and schizophrenia, and in each case it seems to revitalize working memory...