Gene regulation and neurotransmitter questions

[jakan]

I started reading about how genetics works at the cell level on the web, but I need someone to answer some questions I have:

 

1.Genes produce receptor proteins, which then bind to the neurotransmitter or other chemicals. What happens then? How does this then cause the neuron to either fire or not fire? A link to a Wikipedia article would be fine.

 

2.Genes have often have thousands of base pairs, so how come in genetics research they usually only have 2 variations of a gene? Could you point to some descriptions of how different variations of a gene produce different amounts of receptors at a molecular level?

 

3.Are genes each responsible for only one thing? If that is true then different alleles for a neuroreceptor gene would basically only control one thing, the quantity of neuroreceptors produced, right? So if, for example, a certain activity had been shown to up-regulate this gene, would that essentially have the same effect as switching this gene to an allele which produced a higher number of those receptors, or somewhere inbetween?

 

4.For example, lets say a gene exists for which there are two alleles A and B, A produces less receptors for neurotransmitter X, and B produces more, and is associated with a 5 point increase in IQ compared to A. Lets say a person has A. Lets also say that sleep deprivation has been shown to up-regulate production of the neurotransmitter X receptor proteins. Would this basically have the same effect as switching the allele to B?

 

5.If this is the case then all you need to do to change help certain diseases, and give yourself genetic advantages is to find a gene which has been shown to be associated with that area, and then find an activity or nutritional supplement which can affect the regulation.

 

6.How many practical things are there which have been shown to change regulation significantly?

 

7.I know that the BDNF gene can be up regulated very significantly by sleep deprivation, exercise, and antidepressant therapies.

 

8.How often does gene regulation change? Does it change constantly, and can you attribute most changes in your thinking patterns to a gene regulation change?

Edited October 7, 2009 by jakan

[GDG]

I started reading about how genetics works at the cell level on the web, but I need someone to answer some questions I have:

 

1.Genes produce receptor proteins, which then bind to the neurotransmitter or other chemicals. What happens then? How does this then cause the neuron to either fire or not fire? A link to a Wikipedia article would be fine.

 

How about just looking up "neuron" in Wikipedia?

 

2.Genes have often have thousands of base pairs, so how come in genetics research they usually only have 2 variations of a gene? Could you point to some descriptions of how different variations of a gene produce different amounts of receptors at a molecular level?

 

Fortunately, our DNA polymerases are very accurate, and correct their errors (really!). You do find the odd mutation here or there, but many mutations are selected against. If you have a population with a predominant sequence, and a few mutants that occur at frequencies like 1:1000, how many individuals do you have to sequence to find more variants?

 

As for the second part, you can try Wikipedia again...

 

3.Are genes each responsible for only one thing? If that is true then different alleles for a neuroreceptor gene would basically only control one thing, the quantity of neuroreceptors produced, right? So if, for example, a certain activity had been shown to up-regulate this gene, would that essentially have the same effect as switching this gene to an allele which produced a higher number of those receptors, or somewhere inbetween?

 

The mRNA from a gene can be spliced in different ways, so that in some cases you can have several distinct proteins encoded by the same gene.

 

4.For example, lets say a gene exists for which there are two alleles A and B, A produces less receptors for neurotransmitter X, and B produces more, and is associated with a 5 point increase in IQ compared to A. Lets say a person has A. Lets also say that sleep deprivation has been shown to up-regulate production of the neurotransmitter X receptor proteins. Would this basically have the same effect as switching the allele to B?

 

If that was all that sleep deprivation did, possibly. However, it is more likely that sleep deprivation also affects the expression of many other genes: the net result could easily cancel out the upregulation of A. I have yet to meet someone who thinks that they are smarter after they've been deprived of sleep...

 

5.If this is the case then all you need to do to change help certain diseases, and give yourself genetic advantages is to find a gene which has been shown to be associated with that area, and then find an activity or nutritional supplement which can affect the regulation.

 

The system is a bit more complicated than that. For one thing, it is rare to find a disorder that affects only a single gene, for which modulating the gene activity alleviates the disorder. And sometimes the disorder is not the result of differential expression, but of a mutation in the gene that affects (or eliminates) the function of the encoded protein. For example, if you have cystic fibrosis because both copies of the relevant chloride channel gene are defective, no amount of gene modulation is going to help.

 

6.How many practical things are there which have been shown to change regulation significantly?

 

Just about every environmental factor alters the expression of some gene somewhere in the body. Even thinking! If you rehearse something mentally, for example memorizing your part in a play, the neural activity causes the affected neurons to strengthen their synapses -- which requires protein expression -- which requires gene expression.

 

7.I know that the BDNF gene can be up regulated very significantly by sleep deprivation, exercise, and antidepressant therapies.

 

8.How often does gene regulation change? Does it change constantly, and can you attribute most changes in your thinking patterns to a gene regulation change?

 

The regulation state probably changes constantly (although the expression of individual genes may vary only within a narrow range).

 

As for the last question, hard to say. As mentioned above, "thinking" by itself changes the regulatory state of several genes, which directly affects the neurons doing the thinking, which changes the regulatory state again, which ... However, the system (brain, this time) is complex enough that your genes cannot fully determine what (or how) you think.

[jakan]

Thanks for the great reply, GDG.

 

So is gene regulation actually responsible for everything we feel? Like if you are tired is that because of gene regulation?

 

Now evolutionary psychology makes a lot more sense, it would make perfect sense that if you put rats in a novel environment their certain genes would up regulate or turn on so that they would be able to learn better.

 

Is there any way to predict how something would effect gene regulation? Have you ever heard of people using evolutionary psychology to predict how gene regulation changes would happen with different experiences? Like for example cops are put in a situation where they need to be macho ect perhaps this causes gene regulation changes which turn on "alpha male" type genes, and perhaps this could explain the Stanford Prison Experiment.

 

I would like to know exactly how prevalent gene regulation changes are. Is there any research where, for example, researchers would expose people to different types of situations and then measure the changes in gene expression. Like they expose them to a say gambling game, and then measure gene regulation, or force them to make a public speech and then measure gene regulation?

 

If this was in the gene regulation article on Wikipedia then sorry for asking this, but I would really like to know how gene regulation changes could happen based on experiences or environment. It is easy to understand how it could work on a molecular level where one cell is signaling to the other, but when it comes to something where the cause of the gene regulation is an external stimulus, how would that work? Especially if that stimulus is complicated or subtle how would the brain be able to recognize that stimulus and then choose the right genes to regulate? I would assume that for example exposing a male to be around a attractive female probably causes gene regulation changes. But how?

[jakan]

Does anyone have any answers to the questions in my previous post? If I am way off please tell me.

[Mr Skeptic]

So is gene regulation actually responsible for everything we feel? Like if you are tired is that because of gene regulation?

 

Kind of. All of your proteins were produced via activated genes, and the proteins that you don't have were not produced because the genes were not active. The proteins are responsible for making the non-protein components. Actually, RNA does some stuff too but it too is a product of gene regulation.

 

I'm pretty sure that there are some stuff can be accomplished by receptor proteins setting off chemical cascades that don't involve gene regulation. (I base that on gene regulation not being a logical necessity for certain things). However, those receptors were produced by genes which were regulated to be active.

 

Now evolutionary psychology makes a lot more sense, it would make perfect sense that if you put rats in a novel environment their certain genes would up regulate or turn on so that they would be able to learn better.

 

Is there any way to predict how something would effect gene regulation? Have you ever heard of people using evolutionary psychology to predict how gene regulation changes would happen with different experiences? Like for example cops are put in a situation where they need to be macho ect perhaps this causes gene regulation changes which turn on "alpha male" type genes, and perhaps this could explain the Stanford Prison Experiment.

 

Hormones and various signaling molecules have receptor proteins to detect them, and these can be involved in huge amounts of gene regulation. Stress, for example.

 

I would like to know exactly how prevalent gene regulation changes are. Is there any research where, for example, researchers would expose people to different types of situations and then measure the changes in gene expression. Like they expose them to a say gambling game, and then measure gene regulation, or force them to make a public speech and then measure gene regulation?

 

I've heard that gene regulation is part of memory formation, allowing neurons to remember stuff apart from their synaptic connections. Not sure if this was verified or suggested.

 

If this was in the gene regulation article on Wikipedia then sorry for asking this, but I would really like to know how gene regulation changes could happen based on experiences or environment. It is easy to understand how it could work on a molecular level where one cell is signaling to the other, but when it comes to something where the cause of the gene regulation is an external stimulus, how would that work? Especially if that stimulus is complicated or subtle how would the brain be able to recognize that stimulus and then choose the right genes to regulate? I would assume that for example exposing a male to be around a attractive female probably causes gene regulation changes. But how?

 

The brain can do various things that eventually result in chemical signals that travel throughout the body. The chemical signals can be picked up by receptors, which can set off a cascade affecting gene regulation. The most obvious such thing is the glands, such as the release of adrenaline.