When released to certain areas of our brain, this neurotransmitter allows us to resist the need for instant gratification. In other words: this is the key to patience.
- Patience is managed by serotonin, which helps us not give in to instant gratification.
- Serotonin irrigates two parts of our brain which manage two ways of waiting.
Patience is a virtue that must be learned to work. Unlike the rhythm that society imposes on us for instant gratification, patience is like a muscle that works, and that pushes us to complete the pursuit of our goals to really enjoy the fruits of our labor. Researchers from the Institute of Science and Technology at the University of Okinawa (Japan) have succeeded in demonstrating how certain areas of the brain promote patience by using serotonin. The results of their study were published on November 27, 2020 in the journal Science Advances.
Prolong the wait with serotonin
“Serotonin is one of the most famous behavioral neuromodulators, helping to regulate mood, sleep-wake cycles and appetitesays Katsuhiko Miyazaki, a researcher at the Institute of Science and Technology at Okinawa University. Our research shows that the release of this chemical messenger also plays a crucial role in promoting patience, by increasing the time that mice are ready to wait for a food reward.”
The researchers bred genetically modified mice whose particularity lay in the release of serotonin when their neurons were exposed to light. Thus, the neurons could be stimulated by the researchers so that they release serotonin at specific times, when the brain was illuminated using an optical fiber implanted in the cortex.
Thanks to this, they realized that the stimulation of neurons while the mice waited to eat increased their waiting time. This effect on patience was especially observed when the probability that the mice rereceive a reward was high but that the timing of that reward was uncertain. “In other words, for serotonin to promote patience, the mice had to be confident that a reward would arrive, but uncertain when it would arrive.”emphasizes Katsuhiko Miyazaki.
For this study, the researchers drew inspiration from previous work that showed that serotonin is concentrated in an area of the brain called the dorsal raphe nucleus. The released serotonin supplies blood to other areas, such as the nucleus accumbens as well as two parts of the frontal lobe, called the orbitofrontal cortex and the medial prefrontal cortex.
Two patience systems for the same reward
When the researchers stimulated the orbitofrontal cortex and the medial prefrontal cortex of the genetically modified mice with serotonin, the rodents were able to wait longer for their reward. In the orbitofrontal cortex, serotonin release promoted patience as effectively as serotonin activation in the dorsal raphe nucleus. In the medial prefrontal cortex, the scientists found an increase in patience only when the timing of the reward was variable, with no observed effect when the timing was fixed.
“The observed differences in how each brain area responded to serotonin suggests that each brain area contributes distinctly to the mice’s overall waiting behavior.assures Katsuhiko Miyazaki. This supported the idea that these two brain areas calculate the probability of a reward independently of each other, and that these independent calculations are then combined to ultimately determine how long the mice will wait.”
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