Brain Power

*There are approximately 100 billion neurons (nerve cells) in the human brain. That's 100,000,000,000!

*If you were to count all the neurons in the brain (one cell per second), it would take you about 3,171 years.

*Lined up side by side, the neurons in your brain would stretch close to 600 miles.

A Cell Is Born

Your body automatically repairs and replenishes itself. Cut your finger, and new skin cells grow. Break a bone, and specialized cells wrap around the fracture, and new bone tissue grows. Damage your brain cells (neurons), however, and some doctors think you're out of luck. Research in the 1960s convinced scientists that neurons lost to aging or disease can never be replaced.

But in 1998, Dr. Fred H. Gage, a neurobiologist at the Salk Institute of Biological Studies, challenged the accepted view that human brain cells do not reproduce. He assumed that thought-provoking mental activity could stimulate brain-cell growth, just as physical exercise stimulates muscle growth. To prove his hypothesis, Gage placed adult mice in an enriched environment that included exercise wheels, tunnels, and toys. Interestingly, Dr. Gage found that the number of neurons in the brains of these laboratory mice doubled. Furthermore, the growth occurred in the hippocampus- an area of the brain involved in learning and memory. These findings encouraged Dr. Gage to investigate the possibility that neurogenesis (the development of new brain cells) occurs in humans too.

To find out, Professor Gage studied hippocampus brain tissue of five cancer patients who were treated with BrdU, a unique drug that is absorbed only by new cells. While cancer specialists use BrdU to see if cancerous cells are reproducing, Gage was looking for healthy new brain cells, and he found them. Therefore, Dr. Gage concluded that mental exercise can cause new brain cells to grow, enabling us to keep our minds healthy and sharp, even as we age.

A Torah Workout

Today, we trust science exclusively to discover the truth.  And yet, Dr. Gage’s pioneering research on neurogenesis echoed a truth that King David described centuries ago in Psalm 92: “In old age they [righteous people] still produce fruit; they are full of sap and freshness.” According to our tradition, Torah study is essential to Jewish living; in fact, the Talmud says that learning Torah is equal to all the other commandments. An enriched environment of regular Torah study, therefore, can generate new brain cells, keeping us vibrant and productive, even into old age.