One Mechanism for Biological Bases for Behavior

This is a datum to support my assertion that Biological Bases for Behaviors are incorrectly interpreted as "Sin" and that we don't have as much free will as we think we do. The new field of Epigenetics is documenting that regulating gene expression in the brain affects how susceptible we are to maladies such as depression, anxiety and drug addiction.

One viewpoint that I keep pushing around here is that we don't have as much free will as we think we do. I argue that the brain is an electrochemical device where millions of tiny biological switches accept combinations of thousands of analog signals that interact together to turn processes on and off to produce what we call "our self". Now I know there is lot a packed into that statement (presumptions and all) but I want to focus on one molecular mechanism that is a part of all of that.

First, a layman's description of Genes and Gene expression.

What is a Gene?
Genes are a smaller component of DNA. It is made up of combinations of chemicals units called A (Adenine), T (Thymine), G (Guanine) and C (Cytosine). Chromatin proteins called histones compact and organize DNA to form chromosomes. Chromosomes are made up of DNA and reside in the nucleus of a Cell. Chromosomes guide the interactions between DNA and other proteins.

Genes carry chemical information that is used by the cells to collectively determine their characteristics. Each cell contains from 20,000 to 25,000 genes attached to a strand of DNA coiled up into a chromosome, sitting in the nucleus of a cell.

One estimate I found states that there are between 75 to 100 trillion cells that make up the human body. Only in the brain there are estimated to be 100 billion cells interconnected by trillions of synapses (http://www.livescience.com/mysteries/070405_brain_use.html).

Gene Expression
Our genes form the blue prints for proteins. Our bodies are built on proteins, just like a nicely marbled rib eye steak. Accordingly our brains are built on proteins. Every cell has every gene, but each cell only uses a subset of those genes. For a gene to be "expressed" it must be accessed by a chemical catalyst to cause the formation of an RNA molecule. The RNA is then used to make a protein, and the cell uses the protein to carry out its purpose in life, whatever that may be. In the brain, the purpose is to run your body in the background without any conscious effort or knowledge of it on your part and to produce the various stages of consciousness you experience between sleep to stressing out in traffic. Don't forget that while you are stressing out in traffic and worrying about that slow person in your way, you are still listening to the radio, working the pedals, breathing, remembering to call someone when you get in, etc. There's a lot going on that you are not conscious of so it is not accurate to say that YOU are in control, but it is accurate to say that your sense of self is one of those processes going on in the brain that you are not of aware of or even know how to manipulate. But those process are manipulated automatically biologically by a wide range of bodily process which include hormones produced by your organs (the endocrine system). Your brain gets feedback from your organs and it is regulated by them whether you like it or want it or not. Your brain reacts to stimulus and is regulated by the various chemicals that are set into motion as a result. Your experience in traffic changes your mind, your mood, your attitude, your thoughts, your wishes, your desires whether you like it or not. Those molecules that are the catalyst for creating RNA molecules are released, and they go about feeding the cells that your brain is using to handle your traffic experience. Your performance, your emotion, your mood, you thoughts, your access to your memories and your sense of self depends on how well those molecular processes work.

For an RNA molecule to be produced, a chromosome "unravels" (remember that a chromosome is coiled up DNA) to permit the catalyst molecules access to the sequence of ATGC that it is made up of. To "silence" a gene, is to prevent the interaction of the catalyst by preventing it from getting to the uncoiled part of the chromosome or from preventing the chromosome from uncoiling. The body does this on its own, your 'self' doesn't have any choice in the matter, whether it works properly or not. In fact, you or your personality can be modified and you won't even realize it. Just like gene expression causes your pancreas to work properly to do what it is supposed to do, gene expression causes your brain to work properly to do what is supposed to do which is run the processes in your body (such as your sense of self), and create your physical and emotional characteristics that everyone else knows as "YOU".

Now the Hard questions. Were does the soul fit into this? What is "the Soul"? Is the Soul "the personality"? Is the Soul the "I" in "I am alive"? If the personality/soul likes chocolate or to harm animals, can it stop liking those things? Why do people like anything? Am I responsible for things that I like? How do we turn "liking" on or off?

I'll buy a beer for anyone that can tell me why chocolate is so appealing to people. I know why, I'm just looking for audience participation.

One way to turn "liking" off is by manipulating the brain. Its bound to be more reliable than praying and there's no worrying about whether you've got the right god or not.

Nature versus Nurture.
We have been living with this concept since as long as I can remember. What makes one tomato more tasty than another or one person more amicable than another? Finally we know, it is a feedback loop between nature and nurture and we have identified one mechanism by which it happens. Now that this mechanism is revealed, scientists hope to develop treatments for maladies such as drug addiction, schizophrenia, depression and anxiety. Maybe one day they can discover where a specific desire originates from. Maybe one day it can be used to rehabilitate criminals. Maybe one day they can fix the Limbic Systems in psychopaths or make sociopaths more compassionate. Maybe one day they can give me something that will allow me to like mushrooms.

If I were to take a liking to harming animals, and I acted on that, then I am responsible and should be stopped, not necessarily for punishment because punishment may not mean anything to me, but I should be stopped simply to prevent more harm. However, if I have the desire, but do not act on it, since it is "in my heart" the bible says that I am still responsible for it. The desire is born in the brain, electrochemically, and subject to the "nature vs nurture" feedback loop. Since this feedback loop is verifiable, and predictable to a degree, and at least one mechanism for how it works has been identified, to say that human kind is accountable to the creator for "its sin" is as ridiculous as to say that I am responsible for how ugly I am or I am responsible for my dislike of mushrooms or that I even have a choice in the matter.

For further reading
Scientific American Mind, June 2008
* The New Genetics of Mental Illness (subscription or print only)
* Unmasking Memory Genes (subscription or print only)
* Addicted to Starvation: The Neurological Roots of Anorexia

From me on DC
* Reasonable Doubt About Sin: Biological Bases for Behavior
* Sin, Genes, Sugars and Alcohol
* Brains "Trust Machinery" Identified
* "When Our Vices Get the Better of Us"
* Negativity Is Contagious, Study Finds
* Schizophrenia Candidate Genes Affect Even Healthy Individuals
* Brain atrophy in elderly leads to unintended Racism, Depression and Gambling