por How many neurons does the human being have?
It is estimated that the human brain is approximately about 86 billion neurons. It is a figure that was calculated in a 2009 scientific investigation in which scientists used a new methodology.
The number is then close to the 200-400 billion stars in the Milky Way, but it is not the same. On the other hand, until recently it was thought that neurons cannot regenerate; however, it seems that in most mammals they do in the hippocampus and olfactory bulb, through neurogenesis.
The functioning of neurons
The neuron is composed of three main parts: the soma, the dendrites (there are usually several) and the axon.
All electrochemical messages cause thousands of neurons to fire at the same time and transmit the message to neighboring neurons. This connection occurs between the axon of a neuron with the dendrites of another and is called a synapse.
Each neuron communicates in this way with hundreds of neurons receiving electrical charges at a rate of 0.001 seconds, which can occur up to 500 times per second. The most curious thing is that the number of discharges and the value of each one constitute the language of neurons.
Number of neurons in babies
A newborn’s brain has more than 100 billion neurons, many more than it really needs. However, he still lacks dendrites that he will have to develop in the future and which will be the first reason for the weight gain.
In the first years of growth, there is a growth of axons and dendrites and synapses are produced, especially in the cerebral cortex.
In the first 2 years of life, up to 15,000 new neural connections can be formed and 100 billion synapses are reached.
Later, a pruning process occurs whereby unused neurons and unconnected dendrites atrophy and die.
Throughout life, neurons continue to form and die, and new synaptic connections are made, but the rate is not the same as right after birth.
The importance of experience
The development of neurons and their connections does not depend only on genetics and the pre-established; It also depends on your usage. That is, if there are no experiences that make neurons and their connections activate, they will be lost.
However, the death of some neurons may benefit the development of others, and it is believed that the development of the child is due in part to this process.
For example, in fragile X syndrome, children who have it have dense and very long dendrites, in which the process of loss (also called neuronal pruning) has not occurred.
Can neurons regenerate?
Yes, recent research has shown that damaged areas of the brain can be regenerated from cells that become neurons.
Likewise, the adult human brain can generate new neurons, and of course, new connections.
Diet, physical exercise and mental exercise (for example, with cognitive stimulation) are essential to maintain a healthy brain.
Processes that lead to the death of neurons
The brain loses about 10,000 neurons per day and if you have a bad diet, abuse alcohol or other drugs, the number is much higher.
In a binge you can lose up to 1,000,000 neurons.
Stress prevents the new formation of neurons and even kills them.
Hypertension can cause the death of neurons.
Alcohol and smoking tobacco or marijuana also causes the death of neurons.
The drugs.
Fun facts
-The brain constitutes 2% of the weight of the body, although it consumes 20% of the energy.
-The brain receives 36 liters of blood every hour, 891 liters per day.
-If the blood supply to the brain is interrupted, consciousness is lost in a few seconds.
-The brain needs 8-12 glasses of water to function properly.
-The cell body of the neuron is capable of movement, but the majority remains stable (extends the axons).
Number of neurons in other animals
Sea sponge – 0.
Jellyfish – 800.
Leech – 10,000.
Snail – 10,000.
Fruit fly – 100,000.
Lobster – 100,000.
Ant – 250,000.
Cockroach – 100,000.
Frog – 16,000,000.
Mouse – 71,000,000.
Dog – 160,000,000.
Rat – 200,000,000.
Cat – 300,000,000.
Octopus – 300,000,000.
Macaque – 480,000,000.
Capuchin monkey – 600,000,000–700,000,000.
Horse – 1,200,000,000.
Fin whale – 1,500,000,000.
Pilot whale – 3,000,000,000.
Gorilla – 4,300,000,000.
Dolphin – 5,800,000,000.
Chimpanzee – 6,200,000,000.
Killer Whale – 10,500,000,000.
African elephant – 11,000,000,000.