STUDY SEEKS TO DESCRIBE THE MECHANISMS AND DEVELOPMENT OF NEURAL CIRCUITS
FONDECYT PROJECT SEEKS TO DECIPHER CHANGES OF THE NERVOUS SYSTEM AS IT PROGRESSES, AND ALSO TO EXPLAIN THE ORIGIN OF NEURODEGENERATIVE DISEASES LIKE ALZHEIMER'S.
April 4, 2016
“Axonal Remodeling Mechanisms in the Development of Neuronal Networks” is the name of the Regular Fondecyt project developed by academic Juan Tapia, from the Basic Biomedical Sciences Unit of the Department of Health Sciences of our University.
His scientific work considers the nervous system (NS), the human body network of tissues in which neurons are the basic units. Such a system has as main function capturing and processing fast signals, exerting control and coordination on the other organs, so as to achieve an appropriate, timely, and effective interaction with the changing environment.
Likewise, neurons are cells of the NS, whose main work is electrical excitability as they are specialized in the reception of stimuli and the conduction of nerve impulses between them, or with other cell types, such as, for example, muscle fibers.
“Our questions and objectives are quite simple. We want to map a neural circuit. To determine what differences there are between the circuit of a baby and an adult. Then, identify how this neural circuit develops (or changes), and goes from immature (baby) to mature (adult). We also want to know if there are any changes and to determine the mechanism behind these” explained Professor Tapia, scientist in charge for this study, which obtained funding from Conicyt for the next four years.
The academic said that the NS is considered to be the “driving force behind our lives”, because it allows us to connect with the environment through the senses. He argued that the NS also makes us be different and unique, making possible the skills of each person, and in some cases exceptional qualities.
“Perhaps a closer example is the enormous plasticity of the NS that we observe in infants. No child is born knowing to write, read or walk. However, after 1 to 4 years, it is possible to see the tremendous capacity of the NS: they learn to walk and then manage to write and read. This ability does not stop and we continue our development”, said the academic.
The professor stressed that what is sought is to learn what varies as this system progresses. “Is it the number of neurons that change, the synaptic connections? How and when does this process occur? Unfortunately, the answer to these and many other questions in neuroscience are at the moment completely unknown,” said Professor Tapia.
Concerning his research hypothesis, he pointed out that each neuron communicates through extensive connections called axons, which are filiform extensions arising from each neuron and extending as a branch to get in contact with other cells (muscle, glandular, etc), along which nerve impulses circulate.
To know more details about the NS, the project considers building “maps” of neural circuits, in order to identify neurons, their axons and their synaptic connections. “And we are working on it, generating connectivity ‘maps’, using first relatively simple neural circuits. Once we have this map in hand, we want to study the changes that occur in it during its development, from the time they are born until the time they reach maturity,” said the scientist.
About the usefulness and contribution of this work, the academic argued that the alterations in the neuronal circuits could be the cause of many neurodegenerative diseases. “Therefore, our study will not only help to understand the essence of our individualities, but it can also guide us toward the mechanisms behind diseases such as Autism, Alzheimer's or Parkinson's. Once you have identified the mechanism, it is possible to promote the development of therapeutic alternatives that allow for the effective treatment of these diseases,” said the scientist.
One of the expected results is to visualize and understand for the first time the mechanism or mechanisms involved in the development of the above-mentioned neural circuits, and to know what makes each person special and unique.
Juan Tapia also talked about the methodology that will be used in this project. It envisages the study of various types of genetically modified animals. “In one of them, neurons express proteins that can be ‘marked up’ with a multitude of colors. As each neuron expresses a particular color, it is possible to follow each one of its processes, its axon, and ‘identify’ all of their synaptic contacts, and therefore, to know all its interlocutors. Microscopes of the latest generation help us in this task. The combination of these tools, together with computer algorithms developed in the United States, will allow us to meet the goals set out in Fondecyt”, explained the professor from the Department of Health Sciences.
“We’re just at the start of the journey, developing techniques to ‘map’ all of the neural circuits,” he said.