Why do some people prefer stable, predictable lives while others prefer frequent changes? Why do some people make rational decisions and others, impulsive and reckless ones? UCLA behavioral neuroscientists have identified changes in two brain regions that may hold answers to these questions.
Why do some people prefer stable, predictable lives while others prefer frequent changes? Why do some people make rational decisions and others, impulsive and reckless ones? UCLA behavioral neuroscientists have identified changes in two brain regions that may hold answers to these questions.
The research — reported by Alicia Izquierdo, UCLA associate professor of psychology and a member of UCLA’s Brain Research Institute, and her psychology graduate student, Alexandra Stolyarova — is published today in the open-access online science journal eLife.
The new experiments, which involved studying the orbitofrontal cortex and basolateral amygdala brain regions, assessed the ability of rats to work for rewards under both stable and variable conditions. Rats earned sugar pellets after choosing between two images displayed side by side. The animals made their selections by using their noses to touch a screen the size of an iPad. When a rat touched one image, it received a sugar pellet at a predictable time — generally 10 seconds later. When the rat touched the other image, it received a sugar pellet at a time that varied. This was the riskier option as the rats might have to wait as little as five seconds or as long as 15 seconds. The rats did this for a month at a time, as long as 45 minutes each day.
The researchers discovered that the rats learned the task and were able to detect the fluctuations in wait times. When the rats experienced more variation in those wait times for their reward, the amount of the brain protein gephyrin in the basolateral amygdala region doubled, Izquierdo and Stolyarova reported.
Read more at University of California - Los Angeles
Image: A UCLA study has identified changes in brain regions that may hold a key to why some people prefer order and organization and others do not. (Credit: Patricia Marroquin/UCLA)
