For a long time, scientists believed that neurogenesis was impossible. They thought that adults already had all the nerve cells and that these simply died, they did not regenerate. Now we know that this is not true. Neurogenesis exists, and new cells continue to grow in adulthood. Once this question has been clarified, neuroscientists have another challenge ahead of them: what is the function of new nerve cells and how can they be stimulated to grow?
Why are new nerve cells so important?
Many of the nerve cells that are born are responsible for assuming the functions of those that have died. However, neurogenesis is not a mere process of cell replacement but is something much more complex.
Today we know that neurons that are born are completely different from mature neurons. In fact, in the brain of a rodent, for example, only 50% of the neurons that are born live long enough to mature and perform specific functions within the brain.
When a neuron is born, it is not able to connect with the rest and transmit nerve impulses; it takes at least a couple of months for that neuron to grow, migrate and integrate into the already existing neural networks.
However, the best thing about this is that, unlike mature neurons, these have incredible plasticity. Therefore, many neuroscientists believe that one of the most important functions of new neurons is to maintain brain plasticity, thanks to which the brain manages to minimize the effects of functional or structural lesions.
In fact, a review of the scientific literature recently published in the journal Trends in Cognitive Sciences indicates that the growth of new nerve cells improves adaptation to the environment. These researchers focused on the growth of new cells in the hippocampus, an area related to memory and learning.
In practice, the new nerve cells appear to serve to fine-tune the work of the hippocampus when it has to react to certain environmental stimuli, especially when it has to seek pleasurable experiences or avoid stressful situations. Therefore, these cells would help to optimize the person’s response.
However, what is most curious is that a study carried out on mice revealed that positive and pleasurable experiences, such as exercise and sex, stimulate the growth of nerve cells, while stressful experiences, such as lack of sleep and food, led to the death of neurons.
Researchers believe that neurogenesis helps us cope with stressful situations. In fact, it is no coincidence that people with a higher number of nerve cells also have better cognitive performance and show lower levels of anxiety, while a decrease in these cells in the hippocampus not only affects memory and learning but also our ability to cope with the environment, leading to more maladaptive responses that generate even more stress.
How can we apply these results to practical life?
Neuropsychology is not something abstract, but has profound implications for daily life. The growth of nerve cells improves our brain plasticity and our ability to adapt to the environment, so it is important that we adopt lifestyles that stimulate neurogenesis. How can we do this?
– Exercise. Aerobic exercise has been shown to enhance neurogenesis.
– Practice meditation. Meditation causes changes in brain functions and generates a state of well-being, which is why it is also beneficial for promoting the growth of new neurons.
– Learn new things. New learning that represents a challenge not only stimulates curiosity but also the genesis of new neurons.
References:
Opendak, M. & Gould, E. (2015) Adult neurogenesis: a substrate for experience-dependent change. Trends in Cognitive Sciences; 19(3): 151–161.
Redolar, D. et. Al. (2013) Neurociencia Cognitiva. Madrid: Editorial Médica Panamericana.
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