Research reportChange in hippocampal theta activity during behavioral inhibition for a stimulus having an overlapping element

•We recorded the hippocampal theta activity during a feature positive task.•Theta power declined during behavioral inhibition in simultaneous feature positive task.•Decline in theta power related to response inhibition for a stimulus with an overlapping element.

It is believed that a decline in hippocampal theta power is induced by response inhibition for a conflict stimulus having an overlapping element. This study used a simultaneous feature positive (simul FP: A−, AX+) task and a serial FP (A−, X → A+) task. In these tasks, the compound and single stimuli have an overlapping element, and rats are required to exhibit response inhibition for the single stimulus A. We examined hippocampal theta activity during simul FP (A−, AX+), serial FP (A−, X → A+), and simple discrimination (SD; A−, X+) tasks and revealed that the transient decrease in hippocampal theta power occurred during response inhibition for the single stimulus A in simul FP tasks, which provides evidence that a transient decline in hippocampal theta power is induced by behavioral inhibition of conflict stimuli having an overlapping element. Thus, we concluded that the transient decline in hippocampal theta power was induced by behavioral inhibition for the conflict stimulus having an overlapping element.