Is the rat prefrontal cortex crucial for cognitive control during spatial cognition?

Abstract

ABSTRACTCognitive control tasks require that the subject use one class of information and ignore another competing class of information. In prior work, we used an active place avoidance task on a rotating arena that requires rodent subjects to avoid shock by using information about their location in the stationary room and ignore information about their location on the rotating floor. During the task, the discharge of hippocampus neurons alternates judiciously between representing stationary and rotating locations according to the proximity of shock, demonstrating cognitive control directly in the neural representations of hippocampal discharge. The central role of the medial prefrontal cortex (mPFC) in cognitive control is well established in the primate literature, and largely accepted in the rodent literature because mPFC damage causes deficits in tasks that may require cognitive control, as inferred, typically from the task design. Here we test whether rat mPFC lesion impairs the active place avoidance task that requires cognitive control in order to test the “central-computation” hypothesis in which the mPFC is hypothesized to be essential for the computations required for cognitive control. Although ibotenic acid lesion of the mPFC was effective and caused alterations in the coordination of metabolic activity, including the dorsal hippocampus to the dorsal subiculum, its output structure, nonetheless the lesion did not impair active place avoidance. These data support an alternative “local computation” hypothesis: the computations required for cognitive control can occur locally in brain networks independently of the mPFC as a central computational locus for cognitive control.SIGNIFICANCE STATEMENTThe medial prefrontal cortex (mPFC) is considered to be crucial for cognitive control of information, operating with winner-take-all dynamics that allows subjects to make judicious choices in the presence of alternatives. Alternatively, cognitive control may also result from computations in neural circuits such as hippocampus, with a neural architecture for winner-take-all computations. We investigated whether mPFC lesion impairs an active place avoidance task that is demonstrated to require cognitive control that is observed in hippocampus place cell spike train dynamics. We produced mPFC lesions with brain-wide consequences that reduced resting-state coordination of metabolic activity within hippocampus and related areas. Nonetheless mPFC lesion did not impair the active place avoidance task, demonstrating that cognitive control does not always depend on mPFC.