PITTSBURGHCarnegie Mellon University researchers have found that within the brain's neocortex lies a subnetwork of highly active neurons that behave much like people in social networks. Like Facebook, these neuronal networks have a small population of highly active members who give and receive more information than the majority of other members, says Alison Barth, associate professor of biological sciences at Carnegie Mellon and a member of the Center for the Neural Basis of Cognition (CNBC). By identifying these neurons, scientists will now be able to study them further and increase their understanding of the neocortex, which is thought to be the brain's center of higher learning.
Up to trillions of neurons make up the neocortex, the part of the cerebral cortex that is responsible for a number of important functions, including sensory perception, motor function, spatial reasoning, conscious thought and language. Although neuroscientists have been studying the neocortex for 40 years, technologies had only allowed them to look broadly at general areas of the brain, but not at the high-resolution of individual neurons. While they believed only a small proportion of neurons were doing most of the work in the neocortex, they couldn't see if this was indeed the case.
In the current study, published in the journal Neuron, the researchers used a specialized transgenic mouse model developed by Barth to overcome these challenges and clearly see which neocortical neurons were the most active. The model links green fluorescent protein (GFP) with the activity-dependent gene fos, causing the neuron to light up when it is activated. The researchers, including former Carnegie Mellon and CNBC postdoctoral student Lina Yassin, who is now at the Ludwig-Maximillians-Universtat Munich, took recordings from both fos-labeled and unlabeled neurons and found that the most active neurons were expressing the fos gene. The researchers were then able to isolat
|Contact: Jocelyn Duffy|
Carnegie Mellon University