Scientists have long wondered how the brain knows what is going on in the body. Another way to state the question is this: can we see predestination in biological systems?

To consider this, one must first address two complicated facts.

First, the human body has about 100 trillion cells, all of which are derived from a single cell which becomes a fertilized egg on the day of conception. As cells divide, they have to maintain all their genetic information, and yet at each specific location, the cells must differentiate into specific tissues performing very well-defined functions. Any cell growing out of control at any time is bad news.

Second, the fetus has about 200 billion brain cells which need to be made and properly wired before the 20th week of development. Given that 20 weeks contain only 12 million seconds, this means an average of over 10,000 nerve cells are made every second. Nerve cells are not just nerve cells. Each must be properly connected from an organ to a specific location in the brain. Otherwise, every time your toe itches, you might start scratching your nose with no relief. Of course, all these connections have to be done while the rest of the body is still being built.

It is said that the complexity of brain cell development is like asking a toddler to crawl on his own from Manhattan, New York to a certain Seattle suburb to knock on Bill Gates’ door.

One way to build such a complex system is to imagine that nerves that “fire together, wire together.” This assumes that most nerves are innocent until they receive sensory input from either the internal organs or the environment. For example, if the pre-born sucks the thumb, all the nerve endings on that thumb are stimulated. When the signals arrive together to the brain, the brain learns that those nerves must be located next to each other. And so, piece by piece, with different stimulation at different times on different parts of the body, the brain builds up a good idea of where things are located.

The nose, however, begs to differ.

Investigators are astonished that mammals have over 1,000 different detection molecules for odors. They found that when a specific odor molecule hits the nose, a specific kind of nerve gets turned on. Since each nerve can basically make only one kind of detection molecule, the nose must have thousands of different kinds of sensory nerves–all of which must be connected specifically to well-defined, yet different, locations in the brain. How is that possible?

According to conventional wisdom, a nerve’s identity comes from its detection molecule. Surely it should be the binding of the odor molecule to the nerve that tells it who it is and where it should connect to the brain.

Molecular biologists use their bag of “tricks” to determine if this is true. First, they put a “detection” gene in a nerve cell of a mouse so that when that nerve is turned on by the attachment of a specific odor molecule, the cell turns blue in the presence of a certain substrate. Thus, they can trace it all the way from the sensory part in the nose to the brain. That is a long nerve cell. They then repeat the experiment on a different mouse with different odors and confirm that nerves containing the P2 gene connect to a very different location in the brain than nerves containing the M12 gene.

Finally, they replace the P2 gene in a mouse embryonic stem cell with the M12 gene and inserted the modified cell back into an embryo. If the connection was made because of the detection molecule, then the modified nerve should connect to the M12 location in the brain.

Surprisingly, the replaced M12 gene still goes back to the P2 location in the brain, although slightly missing the target. This means the brain has the instructions for the conduction of nerves in the nose before any odor can hit any detection molecule in any nerve. This finding suggests that not everything in the body is a product of the environment.

The next time you smell “Folgers in your cup,” remember that the Creator put that ability in your brain when you were in your mother’s womb. You have the freedom to call it any brand name you want, but the nerves telling you that it is Folgers did not learn it from your experience.

If that is not called Predestination, I don’t know what is.

Suggestions for further reading:

The Mind and the Brain by J.M. Schwartz and S. Begley, Regan Books, 2002.

“Visualizing an Olfactory Sensory Map” by P. Mombaerts et al, Cell, vol. 87, 675-686, Nov. 1996.

(Dr. Richard Yen is a cell biologist, founder of a biotech company and advisor to the West Coast Chinese Christian Conference.)