“The brain uses something as simple as changing the level of sales to control whether we are asleep or awake.” Says Maiken Nedergaard, who in 2013 discovered that the brain has a very simple way to get rid of garbage, simply bailing fluid between cells, without energy expenditure. This finding was considered one of the most important of the year by the journal Science, which now publishes his new job. For more informative topics like this you can also visit http://www.thefaithlounge.com/
Neuroscientists now believe that the brain is “awakened” by a set of neurotransmitter (acetylcholine, hypocretin, histamine, serotonin, norepinephrine and dopamine) that originate in the deep brain structures and the brainstem. This cocktail of chemical messengers, or excitar- serve to activate a set of neurons in the cerebral cortex and other parts of the brain responsible for memory, thinking and learning, leading the brain to a waking state.
However, this model does not explain fully how quickly the brain activated in the billions of nerve cells needed to begin processing information from the outside world or how this activity decays when it’s bedtime. Nor does it explain how the brain keeps waking or oversleeping in time.
But this new research, which will be talking about shows that a simple change in the balance of chemical substances s present in the fluid that bathes and surrounds the cells of the brain can alter the state of consciousness. The study focuses on a set of ions contained in the cerebrospinal fluid (CSF), which changes play a key role in stimulating or damping activity of nerve cells. In addition, these fluctuations in the proportion of sales appear to alter the volume of brain cells, which shrink during sleep, a process that facilitates the elimination of waste, as demonstrated Nedergaard in 2013.
Researchers have used mice to test whether the injection of salt in the brain allows control cycle sleep-wake mouse, regardless of neurotransmitters. In live mice, infusions of artificial cerebrospinal fluid that mimic ion levels during the sleep and wakefulness behave like a switch, which changes the electrical activity of the brain to reflect each respective state. Interestingly, the ion transition from sleep to wakefulness state was much more sudden transition from a sleep-waking state. The authors note that this is consistent with the need for people to awaken quickly to new, threatening or unexpected stimuli.
“Understanding what drives the activation of brain cells is essential to decipher the consciousness and the lack of it during sleep,” says Nedergaard, Center for Basic and Translational Neuroscience at the University of Copenhagen. “We found that the transition from wakefulness to sleep is accompanied by a marked change and sustained concentration of key extracellular ions and the volume of extracellular space.”
In fact, by altering the concentrations of potassium, calcium, magnesium and hydrogen cerebrospinal fluid, the researchers found that they could manipulate the sleep-wake mice in the absence of neurotransmitters. State Potassium, in particular, seems to play a role key when ion levels fluctuate rapidly during the sleep-wake transition.
Although these changes were known in the ion concentration, always they have been considered as a consequence rather than a cause of the sleep-wake cycle, as this new study suggests.
“The fact that the simple alteration of extracellular ion composition may awaken an animal asleep or sleep is direct evidence that this mechanism plays a key role in the regulation of consciousness, ” Nedergaard said.
As ions are positively charged, moving in the cerebrospinal fluid and between brain cells may change the electrical activity of neurons, causing them to polarize and depolarize.When depolarization of neurons occurs, the cells become excitable, and brain enters a state of alert and awake.
These findings, unlike the current theory, do explain how the brain is able to perform the task of activating billions of nerve cells rapidly at the same time and on a global scale when we transition from dream to be awake. You can also show how the brain is able to maintain a state of sleep or waking for an extended period of time by altering the electrical potential of nerve cells.
The researchers also noted that chemical changes influenced the volume of brain cells.Specifically, they found that both neurons and glia cells shrink during sleep, leaving more space for the spinal fluid flow and eliminate waste in the brain, a process that Nedergaard and colleagues first described in 2013.
This discovery reveals that it is not enough to study single neurons to understand brain activity. It must include all support or glial cells, especially astrocytes, which regulate salt levels in the brain. The brain is more than a group of neurons that function as a team. The fact that you need 7-8 hours of sleep to function well reveals that much remains to understand, “Maiken Nedergaard argues.
The identification of this new control mechanism, could point to new ways to regulate sleep-wake cycle, leading to the design of new drugs to sleep. Also help to better understand the prolonged loss of consciousness, such as during a coma. It is also speculated that the changes in the composition of ions play a role in fatigue and deterioration experienced during prolonged periods of wakefulness in people with sleeplessness memory.
This discovery may also be of great importance for research of psychiatric illness such as schizophrenia. And can better understand why people suffer seizures when they stay awake all night, and the post-anesthesia confusion experienced by some people, Maiken Nedergaard highlights.