Tag Archives: neurophysiology

155. Most Complicated Structure in The Universe

22 Mar

I think it is very possible that the human brain is the most complicated and intricate object in the Universe. Of course we don’t know what has developed on other planets, but here on Earth this argument more clearly has merit. My discussion here may convince you of this. I have also written this to show that the brain is so complicated and difficult to study in detail that centuries from now much of it will still remain a mystery. I also want to put to rest notions that we can “download” brain information,  read minds or do much scientific work with large electrode arrays, or construct computers that duplicate brain structure and function. Writers not fully educated in neurophysiology often under-estimate the extreme complexity of the human brain and the impossible difficulty of most cell-interconnection research.

Here is what I learned through my laboratory work and reading the neurophysiology literature for about 50 years. The human brain is composed of billions of nerve cells.  Each cell has connections to many (up to 10,000) other cells. There are perhaps 500 trillion or more interconnections called synapses and gap junctions. Each tiny connection (which functions like some transistor variation) has a complicated and variable structure. Interactions can be digital or analog, and are affected by various hormones and other chemicals. Much of brain functioning involves components that are extremely small, often at the molecular level.

Trying to understand nervous system control points (the logic) when there are, say, 500 trillion units, was rejected by many researchers in favor of starting with simpler systems. For example, Eric Kandel (Nobel prize winner) used the simple nervous system of the mollusk Aplysia, which has a small number of cells. A lot has been learned about cell logic through this type of experimentation. Trying to understand how the human brain works using hundreds of electrodes may have some merit. One problem in working with extremely tiny control points is that it is hard to know exactly where the electrodes are and what you are actually recording from. Also, the electrodes used in the human brain could easily damage the tiny delicate structures. Some cells may have important connections to other distant cells that are not in the electrode array range. Replication would be almost impossible.

When faced with these difficult problems, neurophysiologists have worked successfully (producing valuable info) with various more practical methods. For example, certain brain areas, such as those directly connected to sensory input, are more easily studied. The sensory nerves can be monitored for electrical activity, and the closely associated brain cells can be studied with electrodes, especially in certain animals. The same goes for brain areas closely associated with motor output.

A lot of recent brain research has been done with MRI scans and with EEG (brain waves).  Certain types of conclusions can be drawn from this type of work, but it does not tell us much about the 500 trillion control points.

There are structures and processes in nature that we may never fully understand — like dark energy and black holes.

117. The Amazing Brain: How it was made.

6 Jul

Most people know, or are at least aware of the idea, that our amazing brains were developed through biological evolution. I am going to try to make a clear explanation of this process. One approach is to make comparisons with easy to understand non-biological processes.

A manufactured product can evolve under the following conditions:
1. Consider a product such as a cell-phone, that has a high volume of sales.
2. This product can and will be improved in a number different ways.
3. After each modification, there is an objective measure of the product’s success.
4. The product is permanently modified if there are indications of its success with the public.

So, the procedure is to make and sell a specific improvement, say, a larger screen. If the larger screen sells more phones, then it will be included in all future versions. If sales are worse, then the improved version will be abandoned. In this way, the cell-phone will “evolve” and customers will enjoy better and better phones.

The key factors in this and other evolution are variation (which is persistent) and feedback related to the new features. And, of course, the feedback must have an effect on the persistence of variations.

In biological evolution, mutation (relatively permanent changes) occurs in a species as new DNA is created for offspring. The feedback is success in survival. If a change, such as a longer neck for a giraffe, helps giraffes to survive, then giraffes may “evolve” longer necks. Note, longer necks allow giraffes to reach more food. Natural selection (survival of the fittest) is the biological process, similar to customer satisfaction for the cell phones.

It is really remarkable that “nature” has created automatically self-improving objects like animals and plants. The improvements can take place without any human intervention. Every animal and plant on earth has developed, in this way, for billions of years.

.                           Amazing time leads to Amazing complexity
Now think about this: the amazing complexity of the human brain is based on an amazing amount of time, billions of years. Brains (and all other organs) have developed to a fantastic degree, because of a fantastic amount of time for this “evolution” process to take place.

I should also mention that in our world, there are many types evolution. Similar to natural biological evolution, is animal breeding. Here, the selection is NOT natural, but by humane intervention. As civilization developed, there have been remarkable changes in species to make them more desirable for human use. The clear effects of breeding are very supportive of the concept of natural evolution.

If you want to develop your understanding of brain evolution, do an Internet search on the words “animal nervous systems” or “animal brains” and look at the images. This will help you to see the progression. After the transition from single-celled to multi-cellular animals, rudimentary nervous systems appeared. These provided simple two-cell reflexes based on an input (sensory neuron) and an output (motor neuron). Eventually, more neurons were added to the processing and finally complex brains appeared. Some of this nervous system development is well understood, but there is still very much to learn.