Why Is the Brain Less Active When Given Anesthesia?

Researchers have discovered that certain areas of the brain generate less information when under anesthesia and that's the reason why we lose consciousness.

The reason why we lose consciousness was assumed to be due to anesthetics interrupting signal transmission between different areas of the brain. Researchers have now discovered that when under anesthesia, certain areas of the brain generate less information. //

The research was carried out by the Neuroscientists at Goethe University Frankfurt and the Max Planck Institute for Dynamics and Self-Organization in Göttingen.

Research Reveals Mechanism of Anesthetics
Researchers at John Hopkins Medicine revealed the mechanism of anesthetic action which was previously unknown.

‘Anesthetic is a drug used to prevent pain during surgery and causes certain areas of the brain to generate less information.’

The drop in information transfer often measured when the brain is under anesthesia could be a consequence of this reduced local information generation and not - as was so far assumed - a result of disrupted signal Transmission between brain areas.

If only a few telephone calls are made in a city then it could be the case that several telecommunication systems have broken down - or it is nighttime and most people are asleep.

The situation is similar in an anesthetized brain: if there is remarkably little information transfer between various areas of the brain then either signal transmission in the nerve fibers is blocked or certain areas of the brain are less active as far as the generation of information is concerned.

Why Anesthetics Cause Prolonged Memory Loss Revealed by University of Toronto Researchers
The reason why anesthetics can cause long-term memory loss has been shown by researchers at the University of Toronto's Faculty of Medicine.

Patricia Wollstadt, Favio Frohlich, their colleagues from the Brain Imaging Center at Goethe University Frankfurt and researchers at the MPI for Dynamics and Self-Organization have now investigated this second hypothesis.

As they have announced in the current issue of "PLOS Computational Biology", they used ferrets to examine "source" brain areas from which less information was transmitted under anesthesia than in a waking state.

First Look at Effects of Genetic Copy Number Variation on Volatile Anesthetics
The first estimation of how genomic copy number variation (CNV) can influence anesthetic sensitivity and the magnitude of this influence can be gauged by a new study

They found out that information generation under anesthesia was far more affected there than in the "target" brain areas to which the information was transferred. This indicates that it is the information available in the source area which determines information transfer and not a disruption in signal transmission.

Were the latter the case, a far greater reduction could be expected in the target areas since less information "arrives" there.

Clues to What Makes Anesthetics Work
Very little is known about the intricacies of how inhalation anesthetics actually work in children and adults.

"The relevance of this alternative explanation goes beyond anesthesia research, says Patricia Wollstadt, "since each and every examination of neuronal information transfer should categorically take into consideration how much information is available locally and is therefore also transferable."

Source-Eurekalert