A key mechanism in our brain may be our ability to focus attention quickly, scientists at the University of Queensland have found. The senses constantly send information to our brains, but our level of alertness to this information varies, allowing us to perceive and focus specifically on conversation without others. "If we want to give our full focus, something happens in the brain and neurons to enable us to focus and prevent distraction," explains Professor Stephen Williams of the University of Queensland Brain Institute. "There has to be a mechanism to indicate what we want to focus on." However, this mechanism is not well understood, he says.
Research has shown that electrical activity changes in the brain's "cerebral cortex" when we focus. In conjunction with each other, the cells stop sending signals independently of the "dispersion" and begin synchronization. "This is useful because it allows individual neurons to respond to sensory information in different ways," says Williams. Thus, we can focus on what a friend says in a crowded room or a speeding car on the road. It is known that the brain's cholinergic system plays an important role in releasing this dispersion. "The cholinergic system consists of groups of special neurons that install and release a signaling molecule called acetylcholine, which groups long-term connections throughout the brain."
Increasing evidence suggests that the cholinergic system not only acts as a key, but also enables the brain to determine which sensory information is most prominent and worthwhile at every moment, and then highlights that information. "The cholinergic system is transmitted and sent to the brain, and this is really important to be vigilant," says Williams. He adds that the cholinergic system has already had a far-reaching impact on our cognitive abilities. As he says, the destruction of the cholinergic system in animals destroys perception and memory formation clearly. In humans, the gradual deterioration of the cholinergic system in destructive diseases, which inhibit perception and memory, is strikingly apparent. Alzheimer's is an example. But it is unclear that this key key identifies the neurons that are being targeted and affects their functional ability.
Williams and Lee Fletcher, a researcher at the Queensland Institute of the Brain (QBI), wondered whether the fifth layer of pyramidal neurons and neurons of the neocortex may be causative because they have a big role in how we perceive the world. "The neurons from the neocortex make calculations that are believed to be behind our perception of the world," says Williams. Williams and Fletcher wanted to know whether the cholinergic system could influence the activity of these neurons. Using a technique called "genetic optics", the nerve cells in the cholinergic system were adjusted in the brain of the mice so that they could be activated by flashing the blue light, leading to a sudden release of acetylcholine. This allowed the researchers to monitor the interaction between the cholinergic system and closely related neurons. They found that if the neurons were not active at the moment, much had not been done yet.
But when these neurons received a catalytic input in dendrites, the cholinergic system was able to increase its activity significantly. "It looks like the cholinergic system gave a starting signal, which enabled neurons from the cortex to respond strongly," says Fletcher. What is important is that this change was selective and appears only during the processing of catalytic inputs in the dendrites of the "graduated" neurons. "We have known for some time that the excretions of neurons from the neocortex become active only when animals behave effectively and that activity is linked to cognition and performance," says Williams.
The transformation of mice and rats as a result of this new work shows that the cholinergic system is very important and allows the resulting neurons to perform state-of-the-state calculations. "We propose that this shift also occurs in the human cerebral cortex, allowing us to change our state of alertness and concentration quickly," says Williams. "Our work provides an important insight into how the gradual degradation of the cholinergic system in the disease may undermine human cognition . The result: "The network of the cholinergic system controls the neurons produced by the cerebral cortex."
Source: Eurekalert
0 Comments