Researchers at Nagoya University in Japan say they have identified a brain mechanism that may help explain how people keep working toward a goal as the effort increases. According to ScienceDaily, the study points to orexin neurons as an important part of sustaining motivated behavior.
The findings, published in PNAS, add to scientists’ understanding of motivation problems seen in conditions such as depression, addiction and ADHD. Until now, researchers have not fully understood the brain processes behind these difficulties.
The team, led by associate professor Hiroyuki Mizoguchi and professor emeritus Kiyofumi Yamada, used genetically modified rats to study orexin neurons more closely. Those neurons are already known for helping regulate sleep, appetite and energy use, but earlier research suggested they may also influence motivation.
In tests where rats had to work harder for food rewards, activating orexin neurons led the animals to push through more effort, while reducing those neurons’ activity had the opposite effect. The researchers also observed that orexin activity rose as the rats expected a reward and increased further when the work required became greater.
The scientists say the results suggest orexin neurons are needed to maintain motivated behavior, though simply increasing their activity may not be enough to boost motivation beyond normal levels. The team plans to continue studying the brain circuits that send signals to orexin neurons and receive them.
