You Are the Placebo: Making Your Mind Matter
Download 5.46 Mb. View original pdf
|
| The Biology of Gene Expression Now let’s take a closer look at how genes are switched on. (Several different factors can be responsible, actually, but for the sake of our discussion hereabout the mind-body connection, we’ll keep it simple.) Once a chemical messenger (for example, a neuropeptide) from outside of the cell (from the environment) locks into the cell’s docking station and passes through the cell membrane, it travels to the nucleus, where it encounters the DNA. The chemical messenger modifies or creates anew protein, and then the signal it was carrying is translated to information now inside the cell. Then it enters the nucleus of the cell through a small window, and depending on the content of the protein message, it looks fora specific chromosome (a single piece of coiled DNA that contains many genes) within the nucleus—just as you might look fora specific book on the shelf in the library. Each of these strands is covered in a protein sleeve that acts as alter between the information contained in the DNA strand and the rest of the intracellular environment of the nucleus. In order for the DNA code to be selected, the sleeve must be removed or unwrapped so that the DNA can be exposed (just as a book chosen from a library shelf then has to be opened before anyone can read it. The genetic code of DNA contains information waiting to be read and activated to create a particular protein. Until that information is exposed in the gene by unwrapping that protein sleeve, the DNA is latent. It’s a potential storehouse of encoded information just waiting to be unlocked or opened. You could think of the DNA as a parts list of potentials that are awaiting instructions to construct proteins, which regulate and maintain every aspect of life. Once the protein selects the chromosome, it opens it up by removing the outer covering around the DNA. Another protein then regulates and readies an entire gene sequence within the chromosome (think of it as a chapter within a book) to be read, all the way from the start of the sequence to its end. Once the gene is exposed and the protein sleeve is 102 removed and read, another nucleic acid, called ribonucleic acid (RNA, is produced from the regulatory protein reading the gene. Now the gene is expressed or activated. The RNA exits the nucleus of the cell to be assembled into anew protein from the code the RNA carries. It has gone from being a blueprint of latent potential to being an active expression. The protein the gene creates can now construct, assemble, interact with, restore, maintain, and influence many different aspects of life both within the cell and outside of it. Figure 4.2 gives an overview of the process. Figure A shows the epigenetic signal entering the cell receptor site. Once the chemical messenger interacts at the level of the cell membrane, another signal in the form of anew protein is sent to the nucleus of the cell to select a gene sequence. The gene still has a protein covering protecting it from its outer environment, and that covering has to be removed in order for it to be read. 103 Figure B illustrates how the protein sleeve around the gene sequence of the DNA is opened so that another protein, called a regulatory protein, can unzip and read the gene at a precise location. 104 Figure C demonstrates how the regulatory protein creates another molecule, called RNA, which organizes the translation and the transcription of the genetically coded material into a protein. 105 Figure D shows protein production. RNA assembles anew protein from the individual building blocks of proteins called amino acids. Just as an architect gets all of the information that’s necessary to build a structure from a blueprint, the body gets all the instructions it needs to create complex molecules that keep us alive and operating from the chromosomes of our DNA. But before the architect reads the blueprint, it has to be pulled out of its cardboard tube and unrolled. Until then, it’s 106 just latent information waiting to be read. The cell is the same way The gene is inert until its protein sheathing is removed and the cell chooses to read the gene sequence. Scientists used to believe all the body needed was the information itself (the blueprint) to start construction, so that’s what most of them focused on. They paid little attention to the fact that the whole cascade of events starts with the signal outside of the cell, which is, in fact, responsible for what genes within its library the cell chooses to read. That signal, as we now know, includes thoughts, choices, behaviors, experiences, and feelings. So it makes sense that if you can change these elements, you can also determine your genetic expression. Download 5.46 Mb. Share with your friends:
|