Stress affects your brain. But it can recover
Bruno Giacobbo has been fascinated by stress for a long time. It’s all around us, all the time. ‘Everything we do involves some level of stress. So it’s important to know how it molds our life’, he says.
Research has already extensively shown that stress is related to many modern-day health problems like depression and anxiety, which is why it’s essential to know what exactly it does to the brain. Tiny problem: you can’t cut open a human brain to see what’s happening inside. And it’s also really hard to standardise this kind of research.
So Giacobbo did his research not on humans, but on rats. ‘They’re extremely social animals and very smart. And they react much the same way humans do when they’re put under stress.’
Mimic human situations
He worked on two kinds of stress: the short term sort of – say – an exam week. And the long-term stress. Think of children growing up in a home with abuse.
He mimicked these stress situations in rats by comparing animals he had completely isolated for three months, with animals that had lived the same period of time in a big cage, filled with lots of toys and other rats to play with.
For the short-term stress, he let rats get bullied, by putting a big and aggressive rat in their cage for five days in a row.
Stressed rats get fat
His findings were clear. The rats that had been socially isolated had gained weight. ‘Of course, they didn’t have much more to do than eat and sleep.’ They were also quite restless and fearful. And their short-term memory was way worse than that of the animals that had lived in an enriched environment, with lots of stimuli.
Giacobbo then turned to examining their brains and found differences there too. The socially isolated rats had lower levels of BDNF, a protein that is associated with memory and brain plasticity ‘And in humans BDNF is associated with depression and neurodegenerative diseases.’
Finally, he looked at inflammation of their brains using PET-scans. Again, the stressed animals had more neural inflammation. ‘When that happens for a longer period of time, it can reach a point of no return and the inflammation becomes chronic’, Giacobbo says. ‘The animal will suffer for a long time.’
No chronic effects
Giacobbo’s tests for short-term stress showed happier results. The rats that were bullied for five days in a row showed clear signs of depression, just like the animals that had been isolated for a long time. They were fearful and had more ‘anhedonia’ – an inability to enjoy themselves. ‘We tested that by giving them water with sugar. If they don’t drink it, then we know they don’t experience pleasure.’ Also they refrained from socializing. ‘Which makes perfect sense, of course.’
However, where the long-term stress seems to have chronic effects on the brain, the animals quickly overcame their short-term stress. ‘When we tested the animals two weeks after the tests had finished, the behaviour was gone completely’, says Giacobbo. ‘I really thought they would be stressed out for a long time. But then, suddenly, they were okay again. So that’s sort of a happy ending.’
He advises students experiencing stress to make sure they destress regularly. How you do that, however, is completely up to you. ‘It’s about what feels good for you’, Giacobbo says.