Thursday, October 1, 2009

4. Creating Mind ---- How the brain works by John E Dowling

Creating Mind ---- By John E. Dowling (1998)
W. W. Norton & Company Inc., 500 Fifth Avenue, New York, NY 10110 USA

This is a beautiful book on Brain architecture and function with detailed illustrations. Complex neurological systems are explained in simple terms which makes you visualize and understand. The actual clinical stories are interesting and will give an imagery of what is happening. Specially this is the book to read for in depth understanding of optical and audio sensors.

This book presents a beautiful description of the brain formation, its organization levels and their functions. The autonomous system which controls the human system and the non autonomous which is controlled by human senses are well described

Among all creatures, the uniqueness of humans is Brain. Whatever we do in our daily life as humans are controlled by brain. We learn, we think, we imagine, we work, we relax, we look for comfort, we try to fulfill our desires, we create things, we feel happy, we cry, we feel disgusted; all these are controlled by our brain. How do we do these things, we do not know. But the uniqueness of humans is to try to find out how it is all happening. How we have that inquisitiveness? we do not know. This books explores all these human brain functions.

About three weeks after conception, a group of cells (about 125,000) form a flat sheet along the back side of the embryo. This flat plate is called the neural plate and all the cells (neurons,glial) of the nervous system are derived from here. About 250,000 neurons are created per minute. Almost all 100 billion neurons human brains have are created before human birth.

Unfortunately as humans were born with minimal skills for survival,( it is just like getting a bare bones computer with just an operating system), we have to learn all necessary skills for survival as a dependent starting from walking. we have to start forming neural connections as fast as we could because we start loosing them by 10,000 to 100,000 a day after the age of 20. We have to better start learning all our survival skills before age 20.

The formation of neural plate is interesting. Ectodermal cells which cover the embryo causes the formation of skin and the endodermal cells which are inside embryo lining form stomach, intestine and other internal organs. About a two and half weeks of embryo development, a third, intermediate layer of cells called mesoderm forms. The mesoderm differentiates into many tissues , including muscles, skeleton and cardiovascular system, and also is responsible for the formation of neural plate cells.

Between the third and fourth week of development, the neural plate folds inwards and forms the neural tube. All of the central nervous system originates from neural tube. The anterior part of the tube forms brain and the posterior part becomes spinal cord. By about forty days of development, three swellings appear along the anterior part of the neural tube which eventually become forebrain, midbrain and hindbrain. As the neural tube forms, some cells are left behind on either side of the tube. These cells are called neural crest cells. Much of the peripheral nervous system is derived from these neural crest cells.

Brain uses about 50,000 of about 100,000 genes human genome has to generate for necessary proteins(enzymes) for human body functioning. Out of these 50,000 nearly 30,000 are used only for brain function.

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