NEW YORK, NY (REUTERS).- The brain, which has been humans' biggest advantage in surviving catastrophes and subjugating other species throughout history, is the focus of a new exhibition at the American Museum of Natural History.

"Brain: The Inside Story," which run until August 14, 2011, shows how the human brain evolved over millions of years and uses molecular, chemical and electrical signals to interpret information, weigh decisions and learn at every stage of life.

It allows humans to not just react to the world, but to imagine how it could be and to plan to make those dreams a reality.

"Visitors should take away from the exhibition a sense of awe for their brain," said Rob DeSalle, the exhibit's curator and a geneticist at the museum. "At how it is structured, how it works chemically, how it has evolved and how it changes itself as we develop and grow older."

The exhibit draws on 21st-century research and technology and offers perspective and insight to viewers through imaginative art, vivid brain-scan imaging and dynamic interactive exhibits for all ages.

The human brain weighs about three pounds (1.4 kilograms) and is mostly made of water. But every second a single neuron, the building block of the nervous system, in the brain may send as many as 1,000 signals which can zip from neuron to neuron at speeds of up to 250 miles an hour.

And since a single neuron can connect to at least 1,000 other neurons, a single brain may have at least 100 trillion connections in all.

Yet brain signals, which run on electricity, involve less than one-tenth the voltage of an ordinary flashlight battery.

The exhibit is organized in seven parts including how the brain coordinates the senses, how it processes emotions, and how it allows us to think with intelligence enabling language, memory and decision making.

Research has shown that London Taxi drivers, who memorize every landmark, street and route they could potentially drive, have larger hippocampi, the part of the brain used for long-term memories.

Studies have also revealed that improvising musicians turn down activity in the front part of the brain, the prefrontal cortex, as if to reduce mental control and let their ideas wander.

Neuroscience, the study of the nervous system with the brain the hub, is central to the exhibition and highlights the brain's ability to rewire itself in response to experience, disability or trauma.

After a peak in brain functioning just past age 20, the number of neural connections gradually declines, and over time, memory may become a bit less reliable. The good news is that studies suggest the brain will stay healthy longer if kept engaged with mental and physical exercise.

The exhibition also shows how new technologies are used to treat disorders such as Alzheimer's and Parkinson's.

Doctors can activate, or deactivate, certain brain regions by surgically inserting a wire into the brain and sending in pulses of electricity in what's called deep brain stimulation (DBS). Doctors have already used DBS on more than 80,000 people to treat Parkinson's disease.

Although the treatments are promising, the exhibit also highlights the ethical issues, questioning visitors about whether they should be used to give healthy people increased memory?

(Reporting by Nick Olivari; Editing by Patricia Reaney)

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