General anaesthesia is something created by humans, tested and developed through decades. However, you may find it disturbing that we don’t really know how it works. General anaesthetics put you to sleep by reducing communication between your brain cells, but that’s pretty much all we know. Now scientists from University of Queensland think they are close to cracking the mystery.

And it is a mystery. General anaesthesia has been around since 1850’s, but no one ever really knew how or why it works. A lot of research has been done to make sure our current medication is safe as possible, but its mechanism is not fully understood. Not even close. Now scientists say that the reduction of the synaptic release is the real target. Synaptic release essentially is how nerve cells communicate with each other, how the signal travels through the nerves. Previous researches claimed that general anaesthetics worked a lot like sleeping pills, acting on sleep centres in the brain.

While popular general anaesthetics like propofol does probably act on sleep centres in the brain, scientists say that its effectiveness is actually somewhere else. Scientists say that the propofol disrupts presynaptic mechanisms, cutting the communication between cells, causing a condition, which is very different from just sleeping. People don’t actually feel pain. The effect, as this research showed, is achieved by restricting the movement of syntaxin1A protein, which is required in the synapses. However, scientists do agree that common general anaesthetics put patients to sleep at first. But what does this discovery mean?

Associate Professor van Swinderen, one of the authors of the study, said that this research will have widespread implications. He explained: “The discovery has implications for people whose brain connectivity is vulnerable, for example in children whose brains are still developing or for people with Alzheimer’s or Parkinson’s disease. It has never been understood why general anaesthesia is sometimes problematic for the very young and the old”. As is common in such researches, scientists used brain cells from mice and fruit flies for their experiments – this allows manipulating certain mechanisms. For example, fruit flies with mutations in syntaxin1A protein were more resistant to general anaesthesia.

Anaesthesia is how we do most of the surgeries. It is very important and yet it has some severe side effects. Understanding the mechanism of general anaesthesia could lead to better medicine and more accurate usage.

Source: University of Queensland