How many neurons does the human brain have?
If the human brain is the set of organs that houses the thought, it may be thought that all our mental processes are, in reality, the consequence that there are many nerve cells functioning in our head. However... How many neurons are there in the brain of an average human being?
Knowing this is not easy, since on a microscopic scale the variation in the number of cells is always very large and making mistakes in measurements is very easy. However, it is currently estimated that the brain of an adult person has almost one hundred billion neurons. Or, expressed in numbers, between 86,000,000,000 and 100.000.000.000 (10 raised to 11).
But these figures are not as important as one might suppose at first ...
Recommended article: "Parts of the human brain (and functions)"Massive amounts of neurons and synapses
This figure may seem overwhelming, but it is worth remembering that what really makes the human brain such a complex system is not the number of neurons a person has, but the way in which these neurons interact with each other .
The variability of things that can happen in our brain does not depend as much on the number of neurons as on what they do, the way they communicate. And to know this we have to take into account what happens at the points where these nerve cells connect with each other. These places are called synaptic spaces, and the same neuron can be associated with several of them, by which it receives and sends information.
How many synaptic spaces are there in the adult human brain? 10 raised to 14. That is: 100.000.000.000.000 . In addition, each of these synaptic spaces hosts a lot of events at once: thousands of particles called neurotransmitters are emitted and captured by the neurons that share the synaptic space, and depending on the type of neurotransmitter and its quantity, the neurons will be activated following one or another frequency pattern.
Age also counts
Another aspect that must be taken into account when considering how many neurons the human brain has is that this figure varies depending on the age of the person . The brain of newborns is not much smaller than that of an adult, and has a much higher number of neurons. However, they are nerve cells that are not very connected to each other, and that is why many of them are not yet fully functional.
During the first two decades of life, the process of maturation of mental processes has to do with favoring that the neurons used are connected with each other, not with increasing the number of nerve cells. What makes our ability to think in abstract terms stronger during puberty and adolescence is not that new parts of the brain are born or that the number of neurons grows, but that there are more efficient. This is embodied in a process called myelination, by which large regions of the brain turn white.
This color is a sign that axons, the parts of the neuron that "stretch" to reach neurons that are far away, are beginning to spread in many parts, since this part of the anatomy of the nerve cells is covered. for a whitish substance called myelin.
As for the number of brain neurons, just after the first months of life, when they are beginning to massively connect large amounts of neurons, the human body causes many of them to die . In this way, the material with which these nerve cells are made that are not used can be reused for other things.
How many neurons do other animals have in the brain?
By way of example, or as a curiosity, we can compare those 100,000,000,000 neurons of the human brain with the number of nerve cells that are estimated to have on average other animal species.
- Bee : 960.000.
- Frog : 16.000.000
- Cat : 300.000.000
- Raccoon : 453.000.000
- Rhesus Macaque : 480.000.000
- Chimpanzee : 6.200.000.000
- African elephant : 11.000.000.000.
How are neurons?
If after having read all this you have realized that you do not even know very well what a neuron is, You can read this article to see how is its structure and what are the main types of neurons :
It may interest you: "Types of neurons: characteristics and functions"
