Portal de Murcia
www.portaldemurcia.com
The results reveal that the interpretation prevalent to date on which are the main regions formed at the beginning of vertebrate brain development would not be adequate.
In order to carry out the research, the brain of a non-vertebrate organism (similar to an anchovy fillet), the amphioxus, has been used as a model, which is situated in a branch of the evolutionary tree very close to the origin of vertebrates.
Thanks to the data obtained, the researchers have for the first time made a detailed map of the regions in which the brain of this species, which lives on the seabed and has a very simple life, is divided.
"The work shows for the first time a detailed map of the regions in which the brain of one of the organisms most related to vertebrates is divided, and which could give us an idea of ​​what our ancestor was like"
"We set out to understand how the brain of the cephalopordid amphioxus was. This is a very simple non-vertebrate organism, but very evolutionarily related to us, so it gives us clues about how our ancestors might have been. Territories that present the brain of modern vertebrates with that of amphioxus, we analyze what may have happened to have multiplied and how a complex structure has formed during our evolution, "explains the professor of the Department of Human Anatomy and Psychobiology of University of Murcia (UMU) José Luis Ferrán, one of the researchers in charge of the work.
The research was jointly led by researchers José Luis Ferran and Luis Puelles, from the Department of Human Anatomy and Psychobiology of the UMU;
Manuel Irimia, from the Center for Genomic Regulation;
And Jordi García Fernández, from the Biomedicine Institute of the University of Barcelona (IBUB).
A new model that dismantles many of the above ideas
This work demonstrates that the vertebrate brain would initially have formed from two regions (anterior and posterior), and not from three (an anterior, a middle and a posterior brain) as proposed by the current prosomeric model.
"In this investigation, genoarquitectura is the axis of experimental reference to determine the regionalization of the neural tube of the amphioxo and to compare it with the nervous system of vertebrates. With this vision, a molecular map of gene expression patterns in amphioxo has been generated Whose orthologs would be involved in vertebrates in the establishment and regionalization of the nervous system, "says researcher Beatriz Albuixech-Crespo of the Department of Genetics, Microbiology and Statistics of the University of Barcelona (UB) and IBUB, the first signer of the study.
In the amphioxes no cerebral cortex or an exclusive region has been detected that results in the formation of the middle brain of vertebrates.
However, a common territory has been found within the anterior brain, which has been called DiMes, from which both the middle brain and other important structures of the classic anterior brain were derived.
"From the DiMes territory, three important regions of the vertebrate brain were used to process sensory information"
"As a result of the appearance of molecular signaling centers that cause the expansion and partition of the DiMes portion, the three classical vertebrate brain regions (thalamus, pretectum and middle brain) have evolved," says Manuel Irimia of the Center for Genomic Regulation of Barcelona (CRG) and one of the researchers responsible for the work, which explains that if the function of these signaling centers in vertebrates is eliminated, a single territory is similar to that observed in amphioxes.
The study of the formation of these three important parts of the brain, which serve vertebrates to process visual, auditory or proprioceptive information (on the position and movement of body parts), is useful in understanding how the brain has adapted to the environment and has Been able to process the information around him.
The idea that these regions were formed independently and that each region has given rise to other regions has proven to be erroneous.
"The brain has not evolved in isolation, but has done so because of the interaction of these primitive animals with the environment," says UMU professor.
In short, both brains, the amphioxus and the vertebrate, are divided into two major regions, one anterior and one posterior.
In the case of amphioxus it is observed that the anterior region would have split into two domains, whereas in vertebrates it would be divided into many more portions, including the three regions mentioned that would correspond jointly to one of the parts of the amphioxus.
Knowing the true history of brain formation and the composition of its structures can have important long-term repercussions because it could "serve to explain why a region is altered both in its composition and in its function, for example, it could help us to understand Better the diseases related to the brain and because some regions are affected jointly and others are not, "concludes Irimia.
"Knowing the true history of brain formation and the composition of its structures can help better understand brain-related diseases"
The structure of the brain is the result of an evolutionary process
The human brain has undergone an evolutionary process that began to be designed 500 million years ago in the marine animals that lived immersed in the sand and that gave rise to the first plan of construction of its central nervous system.
This system has been progressively modified and shared by all modern vertebrates.
The study of gene networks that have given identity to different regions of the brain is key to understanding how they have evolved.
That is why, genoarquitectura is a powerful tool to detail the regions of the nervous system, cells and their structures, which allows to determine which genes are active in each territory or region during development and characterize the boundaries between them as well as to define how many different components They originate from each region with great precision.
It is therefore useful to help us recognize in detail how a human's brain resembles that of another vertebrate.
Source: Universidad de Murcia
Privacy policy
- Legal notice
- Cookies