Brains, Genes And Chemical Imbalances

Oh my this one got the commentators responding!

Studies of mental functions, behaviors and the nervous system.

Moderators: Calilasseia, ADParker

Re: Brains, Genes And Chemical Imbalances

#81  Postby Darwinsbulldog » Aug 07, 2014 1:12 am

The incidence of schizophrenia is not just related to genetic errors, but also epistasis. Genetic networks [including genetic regulatory networks responsible for development including the brain] evolve a certain level of fault tolerance and resistance to this noise. A crude analogy would be a door or set of doors. In many people, they have multiple doors or protections against mental instability, but in people likely to develop schizophrenia, the door is flimsy and weak and so a traumatic event can break down the door, causing symptoms. Current practice is mainly biochemical eg by using respiradone and other drug to try and balance the brain chemistry levels of dopamine, seratonin etc, but work is also being done of behavioral "patterning" is in the hope of relieving those symptoms that don't respond to drugs. Short answer, schizophrenia is complex and there are no easy answers. :thumbup:
Jayjay4547 wrote:
"When an animal carries a “branch” around as a defensive weapon, that branch is under natural selection".
Darwinsbulldog
 
Posts: 7440
Age: 66

Print view this post

Ads by Google


Re: Brains, Genes And Chemical Imbalances

#82  Postby Templeton » Aug 07, 2014 3:48 pm

Genetic errors are removed from the gene pool - and with millions of years of evolution, kinda helps with the weeding out.

The point I've been making is that could it be that these "errors" (defects) actually are adaptations in response to environmental impacts? With as many people diagnosed with schizophrenia there sure is an awful lot of genetic errors (defects) in the gene pool. Any chance, especially considering the amount of incidences, that there might be other causes?
The belief in medical science is that genes are the problem...as you're implying.
How can we have so many genes malfunctioning, and still survive as a species? :ask:
Templeton
 
Posts: 473

Country: USA
United States (us)
Print view this post

Re: Brains, Genes And Chemical Imbalances

#83  Postby Darwinsbulldog » Aug 07, 2014 11:35 pm

Templeton wrote:Genetic errors are removed from the gene pool - and with millions of years of evolution, kinda helps with the weeding out.

The point I've been making is that could it be that these "errors" (defects) actually are adaptations in response to environmental impacts? With as many people diagnosed with schizophrenia there sure is an awful lot of genetic errors (defects) in the gene pool. Any chance, especially considering the amount of incidences, that there might be other causes?
The belief in medical science is that genes are the problem...as you're implying.
How can we have so many genes malfunctioning, and still survive as a species? :ask:

Genetic errors tend to be weeded out IF they are visible to selection. And new mutations are added all the time, so there will always be some mutations, because if selection is too hard, a bottleneck in the population will occur, thus making extinction likely. The more population bottlenecks, the more likely extinction will occur. It is that simple. Selection will always be imperfect at "purifying" the gen pool. However, in sexual species you can have very hard selection on the gametes. If a salmon produces 100,000 eggs while spawning, only two need to survive to adulthood [an spawning] for the population to remain stable. Bacteria of course, can withstand popn bottlenecks more easily, and often go in boom and bust cycles.
Jayjay4547 wrote:
"When an animal carries a “branch” around as a defensive weapon, that branch is under natural selection".
Darwinsbulldog
 
Posts: 7440
Age: 66

Print view this post

Re: Brains, Genes And Chemical Imbalances

#84  Postby epepke » Aug 08, 2014 3:02 am

Templeton wrote:What is a gene? What do they do? Do genes make a decision?


If Richard Dawkins has such difficulty defining what a gene is, then I doubt you are going to have much success here.

I apologize if I sounded condescending, that was not my intent


I'd call it more of a straw man than condescension. For all intents and purposes, to a zeroth approximation, when we talk about genes' causing something, what we mean are differential mechanisms affecting phenotype resulting from differences in genetic sequences, leading to different levels of expression of proteins or differences in proteins and other chemicals built with proteins. It is very complex, and of course, the very concept of a gene is an extremely rough approximation, well suited to the ways brains form categories, but not necessarily very good at describing reality. That is, the accuracy of a description is sacrificed to make it understandable.

Example. Once I studied what we called the Cystic Fibrosis gene. It's actually a pretty small region, and there were a variety of mutations that were associated with cystic fibrosis. Even though the region is small, the number of possible mutations associated with cyclic fibrosis was large enough that bioinformatics just to get data to figure out what it was was a significant challenge. I worked with visualizations of codon sequences in a kind of phase space and came up with a general information (not physical) shape that was associated with cystic fibrosis and another one that was not. There was something there, and it could be used to gauge the probability of someone's developing cystic fibrosis. But if I wrote this down or said it every time, people would fall asleep, so I just say "the Cystic Fibrosis gene" taking the rest as read.

Now, if you are criticizing the vapid and banal way that these categories are talked about, as in the gene being a thing that causes disease or some such nonsense, then please feel free to condescend all you like, because it really is very stupid and contemptible. Also feel free to mock talk about "chemical imbalances" and the like.

The cost of this, however, is that we will miss any meaningful discussion using the concept of genetics as opposed to other concepts. Some of this would otherwise be possible, provided that we accept that the concept of a "gene" is an extremely rough approximation.

That is, even given how bad human categorization is (and fortunately through Cognitive Science we are starting to understand just how bad it is), there is a very narrow sweet spot where the categories are taken just seriously enough to say something interesting and construct something testable. It's a difficult range to hit, but without trying, there's no hope of having any discussion or investigation at all, and everything solidifies into untestable dogma or dissolves into semantic much.

It appears that the conversation suggests that genes create disease, and while the Central Dogma in medical science has long believed that the flow of information from the gene is one way, DNA => RNA => Proteins => that assumption is incorrect. Cells in the body receive information from our environment, both internally and externally, and the gene is only a blueprint of information used to adapt to the information received from the current environment.


OK, but this directly leads to the concept of the developmental adaptation, of which many scores are pretty well understood. That doesn't necessarily address the topic under discussion. That is, we don't know enough, I think, to declare these things developmental adaptations. So it doesn't really help a lot.

What I am trying to do may be more radical than what you are trying to do, even. Ironically, because there's a meta-level involved, I want to work toward a position where people know a little bit about what the hell they are talking about, which I don't think people do. I think that a lot of it is just hand-waving. So, when I criticized the DSM and all its axes before, I was disappointed to see an answer talking about some alternate approach. What I meant to convey is that when you have six axes and hundreds of diagnoses, it strongly indicates to me that people don't know what the fuck they are talking about. Getting somewhere here is, I think, a prerequisite for saying, well, just about anything about anything. All we seem to have are a bunch of observed behaviors and names and numbers, and they don't necessarily mean anything. Other than that some people feel and act funny and it causes a lot of problems, I don't really see the elaborate claims and systems as much more useful than a carnival barker's top hat or a homophobic preacher's business suit. There's something going on, but what it is is really anybody's guess, and the £20 words and concepts aren't really helping.
User avatar
epepke
 
Posts: 4080

Country: US
United States (us)
Print view this post

Re: Brains, Genes And Chemical Imbalances

#85  Postby Federico » Aug 09, 2014 1:19 pm

An article recently reviewed by Medical News Today and entitled "Effects of stress can be passed down generations, finds rat study" is particularly interesting because it demonstrates the very important role of epigenetics in heredity.
I will quote a few paragraphs of the article:

".... Researchers at the University of Lethbridge in Canada investigated how preterm births are influenced by stress using an animal model. Rats were used in these experiments as, in general, there is very little variation between rat pregnancies.

The researchers subjected one generation of rats to stress during late pregnancy. The next two generations bred from the stressed rats were then divided into "stressed" and "non-stressed" groups.

The team observed that the daughters of the rats in the stressed group had shorter pregnancies than the daughters of non-stressed rats. Unexpectedly, the granddaughters of stressed rats had shorter pregnancies regardless of whether their mothers had been stressed or not.

As well as having short pregnancies, the descendants of stressed rats also exhibited higher glucose levels and weighed less than the control group
."

"....the study shows that stress across generations becomes powerful enough to induce features that are equivalent to human preterm birth. The team hopes that with further understanding of the mechanisms that generate these epigenetic signatures, it may become possible to predict and prevent preterm birth from occurring in humans.

The researchers add that the findings also have implications outside of pregnancy, as they suggest that the causes of various diseases could be rooted in the experiences of our ancestors.
"
In the End, we will remember not the words of our enemies, but the silence of our friends.(Martin Luther King Jr)
User avatar
Federico
 
Posts: 932
Male

Canada (ca)
Print view this post

Re: Brains, Genes And Chemical Imbalances

#86  Postby Templeton » Aug 14, 2014 6:01 am

Wow, can't a guy go on vacation without all sorts of foolishness springing up? Apparently not... :nono:
Templeton
 
Posts: 473

Country: USA
United States (us)
Print view this post

Re: Brains, Genes And Chemical Imbalances

#87  Postby Darwinsbulldog » Aug 14, 2014 9:50 am

Templeton wrote:Wow, can't a guy go on vacation without all sorts of foolishness springing up? Apparently not... :nono:


And what sort of foolishness would that be, Templeton? :ask:
Jayjay4547 wrote:
"When an animal carries a “branch” around as a defensive weapon, that branch is under natural selection".
Darwinsbulldog
 
Posts: 7440
Age: 66

Print view this post

Previous

Return to Psychology & Neuroscience

Who is online

Users viewing this topic: No registered users and 1 guest