Now I Lay Me Down to Sleep

 (- Copyright ? 2016 by Mike Stewart -)

The Professionals have discovered that there is a large number of neural networks involved in sleeping. These Experts have discovered many details about how we sleep. I am more concerned with why we sleep rather than how we sleep, I will, therefore, not spend a lot of time with these details, but just try to simplify and clarify what the professionals are reporting.

Whether or not we are awake, asleep, or in the process of transferring between these two states, neurons in the brain and brainstem produce a wide variety of nerve-signalling chemicals called neurotransmitters.

The Wikipedia Definition of Neurotransmitters: Neurotransmitters, also know as chemical messengers, are endogenous chemicals that enable neurotransmission. They transmit signals across a chemical synapse, such as a neuromuscular junction, from one neuron (nerve cell) to another "target" neuron, muscle cell, or gland cell.

The meaning I give to this is that neurons produce chemicals that are placed in specific synapses that will cause signals to be sent to other neurons, muscle cells, or gland cells.

To give an inkling of how complex the whole awake asleep process is without getting into all the boring (to most of us) details, let's talk about hormones. From a Google Snippet - "Hormones are chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions. There are many types of hormones that act on different aspects of bodily functions and processes.". Hormones are secreted by glands, and if you remember, neurons can send signals to gland cells (if you do not remember, you have a short-term memory problem as we said this in the last paragraph).

Consider one out of many hormones indirectly controlled by many neural networks as we move from asleep to awake. This hormone is cortisol, also known as hydrocortisone. It is produced by the adrenal gland. From howwesleep.com - "Towards the end of the night, the secretion of the stress hormone cortisol begins to increase in preparation for the anticipated stress of the day, usually capped by a particularly large increase (up to 50%) about 20-30 minutes after waking, known as the cortisol awakening response.".

Sleep itself is defined (from howsleepworks.com) as a naturally-occurring, reversible, periodic and recurring state in which consciousness and muscular activity is suspended or diminished, and responsiveness to outside stimuli is reduced. It has long been known that sleep can be broken down into stages. The number of stages is in some dispute, but one example is Stage 1,  Stage 2, Stage 3, and REM (Rapid Eye Movement). Interestingly, REM sleep is not necessary for survival.

There are numerous theories about why we need sleep, but even the experts agree that these are only theories. Research does show that astrocytes, which are star shaped glial cells, change during sleep and allow more Cerebrospinal fluid to flow through the brain, removing waste products.

Now we need to speculate on why we sleep. The simple answer is Life discovered sometime in the last 1500 million years that many creatures could better survive and pass on their genes if they were self aware and could make intelligent decisions about how to respond to new, unexpected challenges. Sleep is part of the process needed to support self awareness and intelligence.

To give a more specific answer to why we sleep, we need to speculate on what the more than 100 billion quantum computers (which are also known as neurons and glial cells) that make up the human brain are doing while we sleep. This speculation will hopefully not contradict the details the experts have reported and may encourage the experts to undertake new experiments.

Why don't we start in the mind of the three year old who has been frightened by the sudden appearance of a clown. It is now several hours later and the boy is sleeping. To be more specific, the boy is in Stage 2 sleep. In Stage 1, he was drifting off. Now he is "dead to the world". What if we viewed this time, Stage 2 sleep, as the time when neurons were preparing to review the day? Limited dreaming is possible, but only of basic shapes, with no emotional attachments. In this case, I am speaking of the subject of the dream coming from visual input, but I would think you could dream of other basic things, like sounds or smells. All over the boy's brain, during Stage 2 sleep, neurons could be noting, without any emotional judgment, when new things happened during the day. Some of the results of the neuron's internal review might be transmitted to other neurons. If you woke up an older subject during Stage 2 sleep, he might report of feeling of vague, non-specific dreams.

It is probably at this time that the Clown Face neuron and associated glial cells do some serious "thinking". Stage 2 sleep will return several times during the night and this thinking may be stopped and started; or this thinking may continue throughout the night. Other neurons throughout the brain are doing analogous thinking - maybe at the same time, maybe at another time during  the night.

It seems likely that during the night many new neurons, in close proximity to glial cells, are born. By born, we, of course, mean that one cell divides into two cells.

Before we continue, let me introduce some simple  math (multiplication and division) to emphasize how small neurons are. If one thousand new neurons are born each night when we sleep and we live to be 100 years old, we will have an additional 36,500,000 neurons (365 X 100 X 1000). This seems like a large number, but it is negligible (0.0365 %) compared to the total in the brain (100 billion). We would not notice.

The Clown Face Neuron in the mind of the three year old boy, the neuron which gets excited when a clown appears, is just a normal visual input neuron when the boy falls asleep. When the neuron divides, the glial cells change both neurons. Initially, both have information internally about everything visual that had happened that day (plus any important information that might have been inherited from previous days). Based on what has happened that day (before sleep), both neurons are changed with the help of the glial cells. Usually, a day's worth of visual information is cleared from one of the neurons. This neuron becomes the new visual monitoring neuron. The other neuron, which has a synoptic connection to the first neuron, retains its detailed visual information collected during the day. We can now call it a memory neuron and it begins to move toward memory areas in the brain.

In the case of the three year old with the clown problem, we again have one neuron splitting into two neurons. As described above, one of the two neurons becomes the new visual monitoring neuron. This is not to say that this visual monitoring neuron has to be exactly like the one described above. The glial cells may "decide" to strengthen the synoptic connection between the two neurons or make other internal changes to either neuron. The other neuron, the one that is not the new visual monitoring neuron, may become a partial memory neuron, but it remains where it can continue to monitor visual input. Or, alternatively, this neuron may be split again. In this case, we would have one full memory neuron moving to memory areas and a neuron that monitors visual images. Part of its memory has  been cleared - it has been primed to just look for the dreaded clown.

REM sleep was discovered in 1953 by two pioneers in sleep research, Eugene Aserinsky and Nathaniel Kleitman. They observed that, at certain times when people were sleeping, both eyes (underneath the closed eyelids) were moving with a rapid, jerky, synchronized motion - it was as if the sleeping person was watching a rapidly changing scene. Invariably, if one of these people was aroused from REM sleep, he would report a vivid and elaborate dream. Interestingly, when people were allowed to wake up normally, they would often not remember dreaming at all.

Sleep researchers have developed various theories to explain why dreaming evolved. One theory that makes a lot of sense is that dreaming lets a creature review experiences and work out solutions and "best actions" for when and if the creature faces similar situations in the future. Some muscles are paralyzed during REM sleep - a dog dreaming about chasing a cat doesn't need to jump up and go racing blindly through the night.

Dolphins rarely experience REM Sleep. A dolphin can, however, sleep with half his brain tied behind his back - Just Kidding. What I meant to say is Dolphins spend about four hours a day with half their brain in deep sleep and another four hours with the other half of their brain similarly sleeping. Not being dreamers, these creatures have had to evolve another way to manage and benefit from experience. You could say, basically, a dolphin keeps more experience (emotional) details (neurons). He does not summarize. This is not as efficient, but Life was driven to evolve a less than optimal solutions based on one fact. If you paralyze a dolphin's muscles, he tends to drown.

During REM Sleep, many neural networks are active. Is one of these what we call the conscious mind neural network? We said it would have a neuron to slow down thoughts from a thousand a second to a conversational rate - from "I love my cat" to "-----I-----LOVE----MY-----CAT-----". Only in REM sleep, the rate is intermediate "---I---LOVE---MY---CAT---". In REM sleep, this neural network, if it exists, should be named the semi-conscious mind neural network. We are aware, but we will soon forget.

It is theorized that synaptic connections between neurons are strengthened  during REM sleep. In this case, for example, in the sleeping three year old boy, the connections between the clown face neuron and neurons in his fear neural network would be strengthened. This may well be true, but maybe neurons, which are, after all, powerful quantum computers, take an even more active role.

During Stage 2 sleep, although the variety and intensity of brain waves is less than during REM sleep, there is still communication between neurons and neural networks. We could view a dream as the mind (that is, the proper neural networks) playing back events at intermediate speed during REM sleep. We could say a dream is the mind playing a movie.

Remembering that Stage 2 comes before REM sleep, we could speculate that needed preparations for the upcoming film are taking place. What are these needed preparations? One thing that springs to mind is synchronization. There is a need to add a time component to input from various parts of the nervous system. To give a concrete example, suppose the clown that terrified the three year old boy had a clown horn on his belt which he honked loudly just before appearing in the doorway. Synchronization makes it possible for the boy's mind to later know that the sound of the horn and the appearance of the  clown occurred at approximately the same time and to draw valid or invalid conclusions. Synchronization makes it possible for a mind to create a dream with a start, a middle, and an end.

The three year old might not dream about the clown - at least not with a semi-conscious neural network. There is not a problem to be solved. He just wants to be aware as quickly as possible if the clown should appear again so that he can properly panic. The synoptic connections between certain neural network need to be strengthened and glial cells need to act correctly - but all of this could occur while the boy was having a subconscious dream under the control of a subconscious neural network. Philosophical Question: Can you dream and never know you dreamed?

As we remember the Clown Face Neuron not obediently moving off toward the memory areas of the brain, but staying where it is so it can watch for the reappearance of the horrible clown, another question occurs. As we dream, either consciously, semi-consciously, or subconsciously, signals flow from neuron to neuron, from neural network to neural network. Which neuron cells or glial cells are watching and learning from these signals. Could it be ALL 100 billion plus that make up the human brain?

If we don't even have to remember our dreams, what else might be happening as we dream away our nights? If only we had a computer-driven advanced tracking system to view individual neurons and glial cell, to view synapses, to view the creation of tailor made molecules that brand thoughts with our view of reality. If only we had such a tracking system, then we might begin to understand. Until we have such a system, all we can do is speculate and then see if our speculations are supported by reality.

If we don't even have to remember our dreams, what else might be happening as we dream away our nights? Remember the eight year old boy who has an obsession for daily basketball practice? What might be happening as he dreams?

The boy might easily take more than one hundred shots during thirty minutes of practice. Numerous neural networks are active each time the boy fakes, dribbles, shoots, and evaluates. The right neural networks are active at the right time to make the muscles react to send the ball toward the basket.

As the boy dreams, each shot he took that day is not just replayed by his neural networks, but also evaluated. Although the evaluation made when the shot is taken is probably more sophisticated than the boy's simple "I am happy with it" or "I am not happy with it", the analysis that occurs during REM sleep is much more detailed.

We can only imagine the things that are considered. We would expect that successful shots would be scrutinized more than unsuccessful ones. The distance and angle of the shot would be related to other similar shots from the past. The strength, timing, and content of signals between neural networks would be analysed. The results would always be compared to results from the past. Finally, the appropriate neurons and glial cells would use the results to fine tune the strength of synaptic connections between neurons and neural networks. The next time the boy takes a similar shot, he will be a little more accurate, a little better. Over time, he will find that practice makes perfect.

As the boy grows, his neural networks will have to change to correctly control more powerful muscles and a different body. Constant practice will be necessary if the boy wants to maintain or improve his performance.

If we had an advanced tracking system that could tell us throughout the night which neurons or neural networks were becoming excited and signalling other neurons or neural networks, we would gain a greater understanding of dreams. This understanding, however, might not be complete. Glial cells span the entire brain and may impact remote neurons. These neurons may then create, out of thousands of possible structures, one or more small molecules. These molecules, residing in the body of the neurons or in specific synapses, could prime these neurons for possible future states of excitement. 

Night is, obviously, a complex time for our minds. It is, however, a complexity that can be explained by neurons, glial cells, and neural networks.