Let’s face it, we’ve all been disappointed
many many times on occasion. Not to rub it in, but if you were hoping for a Yes vote in Scotland you’re probably feeling some pretty intense disappointment right now. What you might not know is where you’re feeling it, as scientists only just discovered that themselves. In fact, researchers from the University of California, San Diego have not only identified the part of the brain that controls our feelings of disappointment but a connected area that regulates it. (Or tries to, at least.)
It all centres on a small area above the thalamus (which process movement and senses) known as the lateral habenula. As we’ve previously reported, an overactive habenula has been linked to grumpiness. It’s also been implicated in psychosis, as it can cause people to feel both more speeded up and more slowed down. That’s because neurons coming into this part of the brain secrete both glutamate, which makes us feel excited, and GABA, which tells us to calm the heck down. It’s rare for neurons to have two different functions like this, and before this study it had only been observed in two other areas of the brain.
In primates, experiments showed increased activity in the laternal habenula when monkeys expected but didn’t get a drink of juice (cruelty!), leading the scientists to label this part of the brain the ‘disappointment pathway’. There isn’t enough evidence to show decisively that it’s linked to depression, but researchers have hypothesised that it could be. However, it’s not a complete downer designed to make us feel bad: its primary purpose may be to reduce the amount of physical pain we feel.
Image via Ben Grey’s Flickr.