The brain consists of cells called neurons, that are connected by axons, a wire-like projection from the cell body. Maybe one would expect the connection between two neurons to consist of an axon starting from one neuron and ending at the other, but this is not how it works. First of all, there is only one axon, one possibility for the cell to send a message to the outside world. That axon branches and branches and in doing so forms an arbor-like object. The axon usually branches further away from the cell body. Each neuron has on its surface a lot of dendrites, also arbor-like projections from the cell body. Dendrites usually branch near the cell body and do not extend further away. The dendrites receive messages. An axon branch end
clicks on to a spot somewhere in a dendrite by means of the synaptic cleft, a thing we don't go into any further here. So instead of wiring connections directly, neurons connect by clicking axon arbor branch ends onto branch spots in dendrite arbors. Connection of arbor on arbor, as to speak. Direct links are the exception. The branch ends of a single axon can connect to (the dendrites of) many different neurons. A single dendrite can have the axons ends of many different neurons.
A brain part copying procedure
Within 100 up to 200 years millions of nanorobots will travel through the bloodstream to the human brain. They travel in adapted cells or otherwise come to agreement with the immune system. Their target is a chosen part of the brain. Arrived at the destination the nanorobots leave their transport cell and enter a neuron, until every neuron of the chosen brain part contains one nanorobot. Each cell then measures its precise location, by a kind of nano-gps, and send this to the computer outside.
Maybe the robot consists, amongst other parts, of a grid that spreads itself out over the inner wall of the cell. Or maybe it looks like a squid, or spider, a central spherical core and long flexible arms reaching out from it, spreading out over the inner wall of the cell. The nanorobot seeks the places where the axon and all the dendrites grow out from the cell body and puts a thin flexible arm or something like that into it. The arm is able to let the axon fire and in a dendrite it measures and eventually blocks the incoming signals.
Next the robots in different cells make contact with each other. One nanorobot in a cell (neuron A) makes the axon to fire. The signal propagates through the axon, splits at each branch and finally reaches dendrite arbors of e.g. seven other cells. There the signal passes the synaptic cleft and goes through the (usually short) dendrite. Finally it reaches the cell body and the nanorobot in it. The seven nanorobots in the seven different cells notice the signal's arrival and send this to the computer outside the human body. The computer concludes that apparently there is a connection between neuron A and seven other cells. One after the other all nanorobots execute this procedure. Over time a map (map 1) is created of the precise neural network of the investigated brain part, all cell locations and all connections between them. The person in which all this is happening might die some day, but the map of the brain part will remain.
It is a healthy brain part, we know that, the person wherein this is happening, is chosen for that. Elsewhere is another person with this particular brain part being wrong, e.g. damaged by hemorrhage beyond repair. Nanorobots let the cells of the damaged brain part die and drain off the dead cells. Somewhere else in the patient growth of stem cells is initiated that have to move to the the died-off and drained-away brain part. As soon as a new cell is formed, one nanorobot enters it. The maturing from stem cells must wait until the cells have arrived at destination because the axon and dendrites would hinder transport. When arrived at destination the brain cells are allowed to mature. This goes on until at destination an overgrowth of stem cells is achieved.
What's in there?
The nanorobots in the new cells measure their absolute position by nano-gps and the computer outside creates a map (map 2) of the locations of all new brain cells. Subsequently the computer searches for every registered neuron in map 1 of the healthy person the best corresponding neuron (e.g. nearest location) in map 2 of the new brain part of the patient.
As soon as the cells are at location, the connections start to be made. First each cell is incited to develop as much as possible dendrites, so each cell can receive signals. From map 1 the computer knows which connections this cell have to make with which other cells and which connections not. Then the nanorobot incite the cell it is in to develop the axon. That axon must be seduced to grow and branch towards the dendrites of the desired specific cells and not to other cells. How would they do that?
Maybe the target cells that are nearby can be incited by their nanorobots to release a chemical attractant that makes the mentioned axon to branch and grow towards that cells. To avoid intermixing of neighboring target cell attractants, leading to a lot of unwanted connections and a lot of missing wanted connections, maybe different types of attractants can be used for (all too) neighboring cells. However, for target cells further away this will not do, using attractants to seduce over long distances. Maybe then a nanorobot outside the cell releases the chemical attractant just in front of a developing axon branch and guide it towards the far away target cell. All this is very laborious and feels quite insecure. A better procedure is offered by the use of Open End Axons and Open End Dendrites at page 6 of EXISTENCE, that have their axon and dendrite branch ends enveloped by a small box (instead of ending at a synaptic cleft) that can be used to guide its growth.
Suppose we have a brain disease in which not only the brain structure has grown wrong, but also quit a number of genes are doing a lot of wrong things. Let's suppose, in order to cure the disease, it turns out to be useful to replace a brain part in the patient by a healthy brain part structure. Then before the multiplication of stem cells is initiated that have to mature to the cells of the new brain part, the nanorobots first enter one (or some more) of those stem cells, one nanorobot per cell, and head for the nucleus. No spreading out over the cell's inner surface yet. They penetrate the nucleus with their long thin arms and intrude the DNA. One by one they manually replace wrong pieces of DNA by right pieces, handed by nanorobots outside the cell that reach inside with an arm. Where necessary they synthesize DNA on the spot, until finally a proper functioning brain cell has been made - brain cell or stem cell, we have to see what works the best. In case of stem cells (and maybe in case of mature cells too) all this might take place somewhere else in the body, after which the new stem cells migrate through the blood vessels to their destination and start to mature. The new brain part will be made of healthy cells.
When the repaired cells are more or less mature brain cells already, then the cells have to replicate before the axon and dendrite arbor development. I guess the arbors cannot be duplicated in a normal cell division process and it may be the arbors that are the main reason why brain cells do not multiply. And when the brain cells (mature cells or stem cells) are grown elsewhere they migrate to the new brain part destination before the arbor development. I don't think dragging along complete arbors through blood vessels is an option and one cannot know at that faraway place the shape of the arbors on forehand.
The new brain part, when it has grown in and all connections with other brain parts and organs etc. are made, will start to adapt to the old brain parts and vice versa. Using connections will strengthen them while prolonged blocking of the signal will make the connection to disappear. This is a natural process often called use it or lose it. Or maybe the adaption can be guided more or less. You, or others around you, might experience your brain slowly changing over time until this natural adaption has been completed, which may take days, weeks, months or years.
The copying of brain parts seems a routinely process, to be carried out by a computer. One doesn't have to understand the brain part one wants to copy, one just copies its structure. The only demand is that the brain part is localizable. One must be able to decide which cells belong to the wanted part and which cells do not. Some is said in brain part overlap (between the two flower-like
β-signs at the previous page of THE DIRECTION OF TIME).
The process so far assumes that the precise location of axon vertices and the location of the spots in dendrites, where precisely the synaptic cleft is, plays no role. This assumption might be wrong, maybe especially in the memory. We will have to wait until we see.
I guess in a lot of cases it will not be necessary to copy a whole brain part. It will be sufficient to adjust brain properties, like number of axons, emitted amount of neurotransmitter, genes methylizing, and so on. The nanorobots have a lot to do and a lot to learn how.
When you're reading page 6 of this storyline, you see that guiding the axon and dendrite arbors is so much extra work that I guess it cannot be achieved at the start-in-history of the brain part copying process. It cannot take off at the same moment when for the first time nanorobots enter a cell body without disturbing the functioning of its content. First there will be a time of research. Only when open end axons are at ones disposal, which more or less might be at the same time that nanorobots can simulate the cell they are in (at page 6 of EXISTENCE), we can hope all those illnesses will actual be cured, if not prevented from occurrence. Then there will be no opportunity no more to study the illnesses in real life. We can choose the structure of our own brain, our existence, and in my opinion this is an advantage.
The key to reality. All of reality.
With these two things together, the brain part copying procedure and the brain adjusting process, my guess is that it is possible to cure autism, depression, fear, psychosis, addiction and schizophrenia. In combination with the growth of new organs (see next page of EXISTENCE) mental ill institutions, nursing homes, hospitals and prisons will become quit empty.
In whatever stage of your live you are, when you're done with your own brain and like to have a new one for a while, it is just possible. Whatever damage you do to your brain, when you carefully mapped its original structure you will be able to restore your old natural state, if you choose so.
The brain part copying process is not the solution to everything. E.g. the process itself is not creative. But if creativity is in a brain part and if you copy that part, you will still have copied creativity. We will see.
A previous attempt
For quite a number of years I didn't knew each neuron has only one axon. I thought each connection between two neurons always exists of an axon going from one cell body directly to the other. A cell body would have as many axons as there are connections. Then it would have been sufficient to let mature an innumerable amount of stem cells and let them make connections as much as possible, until the new brain part has (as much as possible) each neuron connected with every other neuron via two axons, one forth, one back. Then I thought to strengthen a desired neuron connection by prolonged firing sufficiently long incited by the nanorobot in the appropriate cell body. While unwanted connections would be blocked by the same nanorobot and so would disappear over time. I was sure it would work. I did't knew about dendrite arbors and that there is only one axon that branches further away from the cell body.
When taking into account the arbors, if the axon is fired sufficiently long by the nanorobot in the cell, not only the wanted connections are strengthened but also all the unwanted connections that the axon arbor makes. If one seeks to adjust this by blocking the connection from the other side, blocking the appropriate dendrite by the nanorobot in the cell with which the unwanted connection exists, then not only the unwanted connections are blocked but eventually also a number of wanted connections with other cells that ends in the same arbor of the blocked dendrite. So one actually has to go outside the cell and guide the arbors.
1) Does one (partially) think with its DNA? How much of the brain's mind activity happens IN the cell body of the neuron (but outside the nucleus)?
2) Are all brain functions well separated? If so, what is the shape of the brain parts? Connected points, lines, planes (layers), lumps? See also Brainpart-overlap ... at the previous page in THE DIRECTION OF TIME storyline.
3) If a brain part is altered just a little bit, e.g. at some location the number of existing neurons is enlarged, do the cell nuclei notice this and take measures and restore old condition?
4) How long will the brain part copying process take? And how does the subsequent adaption process will evolve in detail in the course of time?
How to fabricate a nanorobot
First I thought, they can make nanorobots in the way computer chips are made. But one needs flexible robots that can do things, not only rigid chips. Maybe printing will come to the rescue, printing nanorobot parts atom by atom. Will the nanorobot be made of carbon structures like buckyballs, will the grid be made of graphene?
Energy supply. For the nanorobots, carrying a battery along seems no option: just to massive. There is plenty of energy in the body, one only has to find out how to use it. Is such a robot able to send a signal to a computer outside, or will it use a relais-nanorobot nearby that amplifies the signal and then sends it to the computer?