Thursday, March 29, 2007

Why do we Sleep?


Sleep is not an optional enterprise. All mammals do it. So do birds, reptiles, and even fruit flies. Rats deprived of sleep apparently die faster than those deprived of food. Sleep deprivation is a ruthlessly effective means of torture, as the new movie The Lives of Others shows in a stomach-turning scene. Yet the bedrock question—what purpose does sleep serve for us and the rest of the animal kingdom—remains oddly unsettled.

no one knows exactly what the underlying need is.

This Slate article discusses the theory that sleep plays a role in memory consolidation.

2 comments:

Unknown said...

To understand why we sleep we are going to have to ask some new questions. The first of these is "Why do we awaken?". The next of these is "What do being asleep and being awake have in common?".

The problem with asking "Why do we sleep" is that it contains a blatant, misleading presumption of truth which prevents us from even starting at a logical point in this inquiry - that being awake is the way we 'normally' are, and that sleep is something 'different' than what we normally are.

Asking "Why do we awaken" allows us to presume that being asleep is the way we 'normally' are and that being awake is something 'different' than what we normally are.

It is MUCH easier to answer the question "Why do we awaken". This answer allows us to arrive quickly at some very obvious answers - to move around (taking advantage of a much-heightened awareness of our surroundings) to locate nutrition, to ingest what we've found, and to procreate. Other obvious answers, obtainable because of recent science, include the increasing of specific protein enzymes into our bodies at the cellular level.

This provides us with the insight that becoming awake is the behavioral manifestation of changes in our metabolic cycle at the very lowest level - the cellular level. Further, it provides us with the insight that becoming asleep is the behavior manifestation of changes in our metabolic cycle at the very lowest level - the cellular level, that represent a 'return' to the previous state - anabolism.

Anabolism is the metabolic state that identifies an animal as 'being asleep', while catabolism is the metabolic state that identifies an animal as 'being awake'. As anabolism and catabolism are the two balancing metabolic states, so, too, are being asleep and being awake the two balancing behavioral manifestations of the two balancing metabolic states.

We're very comfortable with the concept that our metabolism is functioning properly - we're healthy - and that our metabolism is not functioning properly - we're sick. We should also be very comfortable with the concept that anabolism (growth, healing, immunity at the cellular level) is balanced by catabolism (destruction of cellular structures with the effect that the organism can move around to locate nutrition for later ingestion and digestion, and to procreate - making the organism 'successful'. We should also be very comfortable that as both metabolic states have their advantages, play a role in a complete, total picture of an organism's life, then so, too, do the behavioral manifestations of this metabolic balance - being asleep, being awake - make perfect sense.

We can no more expect that we do not 'need' sleep than we can expect that the cells in our body need to grow, to repair, and to fight off invasions that threaten each cell. We can no more expect that we do not 'need' to be awake than we can expect that the cells in our body can do without the ingestion and digestion of food and do without the procreative act.

Why do we sleep is a question whose answer is right there in front of us if we have the humility to ask these other two questions and to answer them fairly at the same time. Every organism sleeps - exhibits anabolism - and every organism wakes up - exhibits catabolism as it locates nutrition, ingests and digests it, and procreates. It looks like behavior, and, it is, but it's much more than behavior - it's the metabolic imperative - the well-understood balance of cellular metabolism. All we have to do is to accept the idea that cellular activity is cyclical and so is the behavior that manifests itself as a result of the two balancing aspects of cellular metabolism.3142t

StevePocetaMD said...

Obviously a question with no easy answer. I blogged about it last week at:
http://www.revolutionhealth.com/blogs/stevepocetamd/why-we-sleep-3940