One-trial learning, such as avoiding a location where an electrical shock was received, is dependent on the hippocampus and can be blocked by inhibiting the release of epinephrine, adrenaline, and cortisol.

“That effect of avoiding that particular location occurs in one trial. That's a good example of one trial learning. So somehow the animal knows that it was shocked at that location. It remembers that. It is a hippocample dependent learning. They remember it after the first time and every time unless you are to block the release of certain chemicals in the brain and body and the chemicals I'm referring to are epinephrine, adrenaline, and to some extent cortisol.”