An international team of scientists has discovered that serotonin is capable of accelerating learning processes in lab mice, according to a study published today in the journal Nature. The research, carried out by the Champalimaud Foundation, in Portugal, and University College London, in the UK, sheds light on an unknown effect of the serotonin neurotransmitter.
Serotonin (5-HT) is one of the primary chemicals used by neurons to communicate with each other, although its influence on behavior and learning continues to raise questions.
The experts noted that by artificially activating “serotonin neurons” in lab mice, the rodents “adapted their behavior more quickly” to new situations that “required that flexibility,” explains Zach Mainen, one of the scientists.
“That is to say, they gave more importance to the new information and, consequently, changed their minds more quickly when those neurons were activated,” said Zach Mainen.
Serotonin can accelerate learning processes
It was already known, Dr. Mainen recalls, that serotonin contributes to increased brain plasticity and this study reinforces that idea, while showing that this substance is more than just a mood enhancer.
In this regard, experts can now clear why the antidepressants known as SSRIs (selective serotonin reuptake inhibitors) are most effective when combined with conductive therapies, designed to reinforce learning from behavioral strategies aimed at addressing depressive symptoms.
In their experiments, they put the mice in a chamber in which they had to activate a water dispenser on their right and left, “which, with a certain probability, would then discharge water, or not,” describes Madalena Fonseca, from the Champalimaud Foundation.
The researchers observed that the time the rodents spent between two attempts to find water was variable, as they tried immediately, hitting the dispenser, or delayed it a little longer.
This variability led researchers to discover the possible existence of a new effect of serotonin on animal decision making.
Regarding the role of SSRIs in the treatment of psychiatric disorders, the authors suggest that serotonin increases brain plasticity by influencing the pace of learning.