A more predictable past prevents an interest in risk in the future
Taking risks can make sense. If your usual grocery store is closed down, it’s probably worth venturing to an unknown store to get yourself some dinner, rather than wait in the familiar parking lot hoping they’ll reopen. Just how long you’ll think about waiting is tied to dopamine in your brain. And the amount of dopamine your brain produces has now been tied to your, or rather, some roundworms’, previous experiences.
By testing worms in environments with either stable or less predictable food sources, the researchers found that the worms in less stable environments showed more activity on a key circuit in their tiny, 302-neuron brain. That circuit triggered dopamine production, which then activated other circuits associated with learning, changing the worms’ behavior. In this case, they were willing to stray from known territory and venture out for new sources of food.
“What was surprising is the degree to which variability in animal behavior can be explained by variability in their past sensory experience and not just noise,” says Tatyana Sharpee, associate professor and co-senior author of the paper. “We can now predict future animal behaviors based on past sensory experience, independent of the influence of genetic factors.”
Despite this experiment being done with very simple ‘brains,’ the connection between dopamine and risk-taking is already established in many animals. As such, there’s a good chance that this idea will be applicable to more complex brains as well.
My kindergartner asked: What did the worms eat? And were they taken care of to make sure they weren’t drying out? The roundworms, also known as nematodes, were being fed bacteria. Their test environments were hospitable enough to keep them alive so that their responses could be recorded. Drying out on a sidewalk, like an earthworm, wasn’t really a concern for these critters.
Source: How the brain balances risk-taking and learning, Medical Xpress