Friday, July 15, 2005

Thickness of ventromedial prefrontal cortex in humans is correlated with extinction memory

Article published online in PNAS.

The ventromedial prefrontal cortex is a part of the brain which has been show to be involved in fear extinction. In this study, the subjects were conditioned to associate a light with an electric shock. Then they were shown the light without the shock - the extinction phase. The next day they were again shown the light with no shock, to test "extinction retention". Skin conductivity was used to measure fear. There was a correlation between the thickness of the medial orbitofrontal cortex and lower skin conductivity.

Jack in "24" could be pretty thick.

Flying Snakes

Check out the web site for images and movies of the flying snakes of Asia. They jump from trees and then glide of course, they don't truly fly.

Brain Under Surveillance: The Microglia Patrol

Perspective in Science Magazine.

Microglia patrol the brain and shield it from injury. Microglia continually extend (green) and retract (yellow) processes, surveying their immediate environment within the brain. The processes move rapidly toward a site of injury, such as a damaged blood vessel in the brain, in response to the localized release of a chemoattractant (gradient of orange) from the injured sited. Once at the target site, the processes form a barrier to protect healthy tissue.

Researchers have used two-photon microscopy on living mouse brains to image microglia (common brain immune cells) in motion. They genetically engineered the mice so that their microglia were fluorescently labeled.

A previous microglia post