Thinking Beyond Science

Egg and sperm, their union forms a single cell, which will divide and divide again. Within 3 weeks the multiplying cells would have been curled up into a quivering oval ball.

Inside this ball lies a cluster of cells that have become to fall themselves into shape of a garden hose. The bottom of this hose will become the spinal cord and from the top, the brain.

By four weeks just as the mother is discovering that she is pregnant, the first brain cells – neurons are forming at an astonishing rate of 500,000 per minute, neurons that will never reproduce and rarely be replaced.

As the tiny fetus grows, the neurons make their way out through neural tube to build the brain, layer upon layer. These neurons follow a cellular pathway.

While travelling they put their nucleus at the back as they hold on to guide wires(neural tubes). Neurons travel in waves, millions everyday. Scientists call this process migration.

The young neurons have an idea that where they are migrating to and where they will be placed. Neurons are born from stem cells, the seeds from which the tissues of the body grow. Some stem cells can transform into any kind of cell and divide themselves to form more stem cells.

In early infancy or in fetus, everything is connected to everything in our brains, it may be an oversimplification but it’s approximately true as there is tremendous redundancy of connections in brain. There are pruning genes that come and eliminate the excess connections to create the characteristic modularity. If the connections are correct and are being used, they get strengthen, if they are not being used or used occasionally, they are lost.

If the child is born prematurely, the process of forming connections is partially over. So a huge amount of brain wiring is having to happen in the nursery.