The formation of new neurons was an impractical hypothesis just a few years ago. Now it is no longer a hypothesis, it is real, and we have seen it.
I remember when I started my medical career in 2008, and from the beginning we were told that phrase of neurons are the only cells that do not regenerate, the ones we have are the ones there are, and if we lose them we will never have new neurons. Just 2-3 years later they began to tell us that this was possibly not entirely true, and that some areas of the brain showed otherwise.
Today we already know that all this was a mistake, and that up to a third of our brain has continuous formation of new neurons. The first place discovered was the hippocampus, where we believe memory forms, but there are probably many more areas. And now we have gone further, as we have just seen it live and direct.
The formation of new neurons in a living brain
At least that is what the recent research published in the magazine affirms. Neuron in charge of Columbia University Medical Center (New York), who have had to combine various optical microscopy techniques to observe this formation of new neurons in the brains of living mice.
In the work, led by Attila Losonczy, it has been shown that such formation of new neurons is vital for learning and memory formation (at least in mice), a hypothesis that we already had practically previously confirmed. According to them, this finding could help us to treat various psychiatric disorders such as depression, anxiety or stress.
The formation of new neurons is real, not a myth
In order to visualize this formation of new neurons, the team of researchers had to perform various experiments on the brains of live mice. In one such experiment, the mice ran on a treadmill while the researchers adjusted different visual, sound, or olfactory perceptions: For example, hear low tones, smell a banana scent, and see a blue light; other times they made them smell lemon and see with flashing lights. While sensing these sensations, the team attached small discharges to the rodents, as a form of unpleasant association of the sensations.
After this, the researchers deactivated the new neurons by light, using the optogenetic. Unsurprisingly, after disabling these newly created neurons to associate perceptions with something unpleasant, the mice no longer distinguished safe signals from unsafe signals: They had lost their fear of losing the neurons that created it.
The formation of new neurons, key to treating neuropsychiatric disorders
The researchers claim that this inability to discriminate safe from unsafe situations could be key in some neuropsychiatric contexts such as panic disorders or stress and anxiety disorders (For example, I heard an exhaust pipe and reacted with fear for thinking it was a shot in a situation that did not proceed).
According to the authors of the work, this formation of new neurons (or the lack of them) could explain the origin of these disorders. In fact, they have hypothesized that disorders such as schizophrenia or depression could have some alteration in the birth of new neurons, which implies that the finding may help us improve current treatments for these diseases in the not too distant future.
Going | New ScientistSource | Neuron.