How Your Brain Works

Your Brain – General Features

The Human Cortex

The most striking feature of the human brain is seen in the cortex. This is the folded, hemispherical structure which constitutes the bulk of the visible brain.

It is not present in reptiles.

The cortex is relatively recent. It is perhaps one hundred thousand years old and is the part of the brain most closely associated with our ability to form complex representations of the external world, to reason logically and to use language.

It is much more dominant in humans than in any other species.

Regions of the cortex control vision, our auditory senses, and voluntary movement and touch sensations. It is also crucial for long term memory.

Neurons and Networks

The central nervous system is composed of something like one hundred billion nerve cells or neurons.

Each nerve cell or neuron possesses a single axon along which it can pass electrical signals to other neurons. Incoming signals are carried by a neuron’s dendrites which form a tree-like structure around the neuron.

Neurons are about one micron (1 millionth meter) in diameter. The dendrites are perhaps ten times this in length while the axon varies from a millimetre up to one metre in length.

The signal from one neuron reaches another at the junction of axon and dendrite — the synaptic gap.

The typical voltages associated to these signals are small (tens of millivolts) and travel at about two hundred miles an hour (100 metres per second)

Typically neurons can only fire once every millisecond (one thousandth of a second)

Different patterns of electrical firing activity are associated with different brain functions.

Learning and Connections

The brain is both robust (able to function in the event of severed connections and/or dead neurons) and plastic – able to adapt to new memories and functions.

This is due to ability of the brain to form new connections between neurons. These connections take place at synapses and are
mediated by the release of neurotransmitter chemicals.

These neurotransmitters alter the effective strength of the signal which can pass between
neurons.

During our early years and during any kind of learning process these connections form and change their strengths.

The power of the brain as a computational device derives from the complex network of neural pathways and the simultaneous processing capability of all the neurons.

One such immensely powerful device belongs to you.

You can personally programme this device (your brain) to deliver everything you have ever truly desired.

This Genie within you is simply waiting to be told what it is you want.

So set your Genie some exciting tasks to perform and pilot yourself to a future of positive expectation.

Important Events And Discoveries In Biotechnology

1977:

The Age of biotechnology arrives with “somatostatin” – a human growth hormone-releasing inhibitory factor, the first human protein manufactured in bacteria by Genentech, Inc. A synthetic, recombinant gene was used to clone a protein for the first time.

1978:

Genentech, Inc. and The City of Hope National Medical Center announce the successful laboratory production of human insulin using recombinant DNA technology. Hutchinson and Edgell show it is possible to introduce specific mutations at specific sites in a DNA molecule.

1979:

Sir Walter Bodmer suggests a way of using DNA technology to find gene markers to show up specific genetic diseases and their carriers. John Baxter reports cloning the gene for human growth hormone.

1980:

The prokaryote model, E. coli, is used to produce insulin and other medicine, in human form. Researchers successfully introduce a human gene – one that codes for the protein interferon- into a bacterium. The U.S. patent for gene cloning is awarded to Cohen and Boyer.

1981:

Scientists at Ohio University produce the first transgenic animals by transferring genes from other animals into mice. The first gene-synthesizing machines are developed. Chinese scientists successfully clone a golden carp fish.

1982:

Genentech, Inc. receives approval from the Food and Drug Administration to market genetically engineered human insulin. Applied Biosystems, Inc. introduces the first commercial gas phase protein sequencer.

1983:

The polymerase chain reaction is invented by Kary B Mullis. The first artificial chromosome is synthesized, and the first genetic markers for specific inherited diseases are found.

1984:

Chiron Corp. announces the first cloning and sequencing of the entire human immunodeficiency virus (HIV) genome. Alec Jeffreys introduces technique for DNA fingerprinting to identify individuals. The first genetically engineered vaccine is developed.

1985:

Cetus Corporation’s develops GeneAmp polymerase chain reaction (PCR) technology, which could generate billions of copies of a targeted gene sequence in only hours. Scientists find a gene marker for cystic fibrosis on chromosome number 7.

1986:

The first genetically engineered human vaccine – Chiron’s Recombivax HB – is approved for the prevention of hepatitis B. A regiment of scientists and technicians at Caltech and Applied Biosystems, Inc. invented the automated DNA fluorescence sequencer.

1987:

The first outdoor tests on a genetically engineered bacterium are allowed. It inhibits frost formation on plants. Genentech’s tissue plasminogen activator (tPA), sold as Activase, is approved as a treatment for heart attacks.

1988:

Harvard molecular geneticists Philip Leder and Timothy Stewart awarded the first patent for a genetically altered animal, a mouse that is highly susceptible to breast cancer

1989:

UC Davis scientists develop a recombinant vaccine against the deadly rinderpest virus. The human genome project is set up, a collaboration between scientists from countries around the world to work out the whole of the human genetic code.

1990:

The first gene therapy takes place, on a four-year-old girl with an immune-system disorder called ADA deficiency. The human genome project is formally launched.

1991:

Mary-Claire King, of the University of California, Berkeley, finds evidence that a gene on chromosome 17 causes the inherited form of breast cancer and also increases the risk of ovarian cancer. Tracey the first transgenic sheep is born.

1992:

The first liver xenotransplant from one type of animal to another is carried out successfully. Chiron’s Proleukin is approved for the treatment of renal cell cancer.

1993:

The FDA declares that genetically engineered foods are “not inherently dangerous” and do not require special regulation. Chiron’s Betaseron is approved as the first treatment for multiple sclerosis in 20 years.

1994:

The first genetically engineered food product, the Flavr Savr tomato, gained FDA approval. The first breast cancer gene is discovered. Genentech’s Nutropin is approved for the treatment of growth hormone deficiency.

1995:

Researchers at Duke University Medical Center transplanted hearts from genetically altered pigs into baboons, proving that cross-species operations are possible. The bacterium Haemophilus influenzae is the first living organism in the world to have its entire genome sequenced.

1996:

Biogen’s Avonex is approved for the treatment of multiple sclerosis. The discovery of a gene associated with Parkinson’s disease provides an important new avenue of research into the cause and potential treatment of the debilitating neurological ailment.

1997:

Researchers at Scotland’s Roslin Institute report that they have cloned a sheep–named Dolly–from the cell of an adult ewe. The FDA approves Rituxan, the first antibody-based therapy for cancer.

1998:

The first complete animal genome the C.elegans worm is sequenced. James Thomson at Wisconsin and John Gearhart in Baltimore each develop a technique for culturing embryonic stem cells.

1999:

A new medical diagnostic test will for the first time allow quick identification of BSE/CJD a rare but devastating form of neurologic disease transmitted from cattle to humans.

2000:

“Golden Rice,” modified to make vitamin A. Cloned pigs are born for the first time in work done by Alan Coleman and his team at PPL, the Edinburgh-based company responsible for Dolly the sheep.

2001:

The sequence of the human genome is published in Science and Nature, making it possible for researchers all over the world to begin developing genetically based treatments for disease.

2002:

Researchers sequence the DNA of rice, and is the first crop to have its genome decoded.

2003:

The sequencing of the human genome is completed.