Many neuroscience studies in animals involve some type of short-term (or acute) manipulation of the brain, followed by behavioral tests. When manipulations of a specific brain circuit are followed by behavioral changes, neuroscientists generally conclude that the circuit contributes to the behavior that's been changed.
But brain circuits are very densely packed and highly interconnected, so it’s hard to manipulate one without influencing others. This makes it particularly challenging to know if the behavioral effects are caused by the part of the brain that was targeted or by some other part that happens to be closely connected to it.
A paper published in Nature shows that short-term alterations and long-term damage can have different effects on behavior. The findings raise a significant caution about the cause-and-effect nature of manipulating the brain and provide a reminder that the brain can sometimes work its way around damage.