Mr.Samsa wrote:Federico wrote: Enough for today, Mr.Samsa: I'm sure you'll have some more questions tomorrow.
Nope, just the same question since you didn't answer it:
Simple question for you: Do you accept that the brain can grow and connect neurons in different formations, and grow entire brain structures, without any change at all in the genetic structure?
And if so, why are you arguing that this basic, well-understood, process is better understood in epigenetic terms when no scientist agrees with you?
(If you're confused, I'll give you a hint: Your copied and pasted links have absolutely
nothing to do with my question).
Simple answers for you, Mr.Samsa.
To the first question the answer is: It depends. When a stem cell goes on to differentiate into neurones while migrating into what will become a brain under the influence of many factors, she is pluripotential and possesses all the machinery necessary to differentiate into anyone of the body cells. Then, neurones will multiply together with glial cells and other non-neuronal brain cells, the axons will grow, dendrites will multiply, interneuronal connexions will proliferate, etc.
All this will presumably be done without any changes in the information contained in the cell nucleus (chromosomes + histones).
The neurones will differentiate into specialized cells such as visual, auditory, for taste, for smell, for Hypothalamic Rfs, for movement, for balance, but also for memory, for pleasure, for making music, etc and migrate to form specific brain structures without the need for changes in the baggage of instructions carried in the Genome+Epigenome functional machinery.
However, if something happens during the two crucial periods of fast brain growth and differentiation (
In utero and during infancy) such as environmental alterations (lack of food, stress, exposure to smoke, alcohol, toxic substances, during pregnancy, and mainly lack of proteins in infancy), these may interfere with genes' function not by a genetic mutation, but by an alteration of the epigenetic control of genes' function, and thus result in some brain dysfunction.
Good night.
In the End, we will remember not the words of our enemies, but the silence of our friends.(Martin Luther King Jr)