[div class=attrib]From Neuroskeptic:[end-div]

After a period of heavy use, hard disks tend to get ‘fragmented’. Data gets written all over random parts of the disk, and it gets inefficient to keep track of it all.

That’s why you need to run a defragmentation program occasionally. Ideally, you do this overnight, while you’re asleep, so it doesn’t stop you from using the computer.

A new paper from some Stanford neuroscientists argues that the function of sleep is to reorganize neural connections – a bit like a disk defrag for the brain – although it’s also a bit like compressing files to make more room, and a bit like a system reset: Synaptic plasticity in sleep: learning, homeostasis and disease

The basic idea is simple. While you’re awake, you’re having experiences, and your brain is forming memories. Memory formation involves a process called long-term potentiation (LTP) which is essentially the strengthening of synaptic connections between nerve cells.

Yet if LTP is strengthening synapses, and we’re learning all our lives, wouldn’t the synapses eventually hit a limit? Couldn’t they max out, so that they could never get any stronger?

Worse, the synapses that strengthen during memory are primarily glutamate synapses – and these are dangerous. Glutamate is a common neurotransmitter, and it’s even a flavouring, but it’s also a toxin.

Too much glutamate damages the very cells that receive the messages. Rather like how sound is useful for communication, but stand next to a pneumatic drill for an hour, and you’ll go deaf.

So, if our brains were constantly forming stronger glutamate synapses, we might eventually run into serious problems. This is why we sleep, according to the new paper. Indeed, sleep deprivation is harmful to health, and this theory would explain why.

[div class=attrib]More from theSource here.[end-div]