Neurons are specialized cells that perform a wide variety of very important functions for the proper functioning of the nervous system and, therefore, of the whole organism. These important cells may last longer than many people think.
When you try to think about the lifespan of a neuron, it’s quite possible that the idea that it doesn’t usually live long will come to mind, and we’ve probably heard, read, or discovered something hand that the cells of our body tend to destroy and renew themselves continuously; however, this process is not the same in the case of neurons.
In this article we will explain how long a neuron lives; but first we will see what exactly a neuron is, what are its main functions and we will also briefly explain the different types of existing neurons.
What exactly is a neuron?
Neurons are specialized cells responsible for building the nervous system. Among their main functions, it should be noted that they are responsible for receive, process and transmit information via two different types of signals: chemical and electrical, this being possible thanks to the electrical excitability of the plasma membrane they have, which is a layer that delimits the entire cell.
The neurons are divided into different parts: the neuronal body or soma, the nucleus, the axon, the dendrites, the myelin sheath, the nodes of Ranvier, the substance of Nissl, the synaptic buttons and, finally, we can find the axon cone
Similarly, neurons are responsible for receiving various stimuli and also for the conduction of nerve impulses between neurons by connections called “synapses”or even with other types of cells (for example muscle fibers).
There are three classes of neurons: sensory neurons, which are generally responsible for transporting information from sensory organs (eg eyes) to our brain; motor neurons, would be those that have long axons and are responsible for transporting indexing from the central nervous system (CNS) to the muscles and also to the glands of the body; finally there are interneurons, which have shorter axons and are responsible for establishing communications between neurons, never with muscle fibers or sensory receptors.
On the other hand, neurons are created from stem cells in the subgranular zone of the hippocampus and also in the subventricular zone in a process known as “neurogenesis” (the birth of new neurons). Normally, adult neurons do not have the ability to reproduce; however, some more recent studies claim that it has been possible to observe that certain types of neurons reproduce.
How long does a neuron live?
Let us now address the question of the longevity of human neurons. If we stop to think about the lifespan of a neuron, we will probably imagine that these specialized cells of our nervous system do not live too long, as is the case with other types of cells. present in our body; However, this idea is no longer true the lifespan of neurons differs a lot compared to other cells which are normally reproduced and destroyed continually throughout our lives.
Thanks to the research carried out in recent years, it has been possible to verify that the neurons that we have in our brain are the same age as us, since they have been there since our birth, unlike what happens with the cells of other parts of our body that are replaced every time (for example, skin cells are usually renewed every month).
Therefore, if someone asked us how long a neuron lives, they would probably be surprised at our answer now that we have been able to find it, thanks to the data that various surveys reveal that neurons could live even longer than us. Moreover, some scientific theories have developed the hypothesis of the possibility that they can live indefinitely.
If this were the case, with the future progress of science and medicine, as well as good habits of life, in the event that human beings manage to increase their life expectancy significantly (ex.: exceed 120 year) the neurons will continue to functionwhich could be very promising.
In addition, thanks to specialized research in the matter, it has been observed that when a person dies, a large percentage of their neurons are intact; in other words, these neurons which accompany a person until the end of his days, have done so since his birth. But despite this, when the person’s organism stops functioning, the neurons are gradually destroyed.
Does this mean that neurons are not destroyed throughout our lives?
There is a study that was done in 2013 by neurosurgeon Magrassi and his collaborators where they investigated mice that involved making a neural implant of the brains of some mice into other mice. The results are surprising, since these transplanted neurons managed to live up to 36 months longer on average than the mice that carried them in their brains.
The conclusion of this study reaffirmed the hypothesis of further investigations that some neurons could possibly be immortal if they were in a body capable of sustaining them.
Now, although there are neurons that are born with a person and die when they die, that doesn’t mean that all the neurons that person has in the brain live the same way they do. Actually, the brain can manage to keep part of the total number of neurons that the person had at birth throughout his life.
It should be mentioned, on the other hand, that there is a process called “neural pruning”, by which over the years the synaptic connections that are not used are eliminated, being a process contrary to what happens when some are used a lot of connections between neurons so that these are strengthened and they can also be able to interconnect with other new ones.
On the other hand, neuronal death usually occurs due to certain degenerative disorders, as can be the different types of dementia and it could also be caused by different traumas experienced, especially at an early age or due to certain infectious, immune or inflammatory diseases, among others. However, another process known as neuronal regeneration or neurogenesis can also occur, which would be the ability of neurons to regenerate, although this usually only happens in certain areas of the brain, so it’s not very running.
This neurogenesis usually occurs in two parts of the brain, the olfactory bulb, which is the area of the brain responsible for smell (although in this case this normally only occurs until the age of 18) and the hippocampus, which is the area of the brain which is particularly involved in memory and also in navigation through the environment. Apart from isolated cases and certain regions of the brain, such as those we have just mentioned, the rest of the neurons that we have are the same age as us and will accompany us for the rest of our lives.
Could the lifestyle we lead influence the lifespan of our neurons?
When thinking about the lifespan of a neuron, the question of whether our lifestyle can influence the lifespan of these cells may also come to mind. We could answer this question with a yes but with nuances because there are several factors that influence the life of neurons, as well as health in general, which are beyond our control (for example, suffering from certain diseases).
However, it is known that there are several factors that we can control and that can promote the extension of life and therefore the maintenance of a greater number of neurons for as long as possible.
Therefore, what we can do to keep our neurons in better condition are good habits and a healthy lifestyle. (e.g. maintaining a good diet, exercising, learning continuously throughout our lives, etc.) as you know. found that good habits prevent cognitive decline and at the same time help strengthen brain synapses.
On the other hand, bad habits, such as alcohol and other substance abusein addition to being sedentary and the lack of continuous learning, although no conclusive results have been found regarding the hypothesis that they could directly destroy neurons, it has been observed that they damage the development of synapses neuronal and this can affect various brain connections responsible for strengthening various functions such as memory or logical reasoning, among others.
In addition, if they start developing these bad habits at an early age, it could harm the correct and complete development of the brainso that the full potential is not achieved and this could have significant long-term negative consequences.
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