Determination of functional connectivity between the frontal and auditory cortices in rats during the performance of visual and auditory tasks

To process sensory information and guide behavior in dynamic environments, the brain relies on precise cortical connectivity, with selective attention playing a key role. While top-down control is well-characterized in the visual cortex, its operation in the auditory cortex (AC) remains unclear. This study evaluates functional connectivity between the medial prefrontal cortex (mPFC) and AC in rats during selective attention tasks. Animals were trained in two-alternative forced-choice (2-AFC) tasks under visual and auditory modalities, with simultaneous Local Field Potential (LFP) recordings in the mPFC and AC. Behaviorally, subjects learned both tasks successfully, showing significant modality-dependent performance differences. LFP spectral analysis revealed oscillatory modulations dependent on learning stage and sensory modality. Granger Causality analysis was implemented to determine interaction directionality. The main finding revealed significant differences in top-down information flow between tasks: during the visual modality, a marked, statistically significant increase in top-down beta-band flow occurred during target stimulus presentation. This signature evidences strong directional communication from mPFC to AC during the visual task, suggesting an mPFC-driven inhibitory control mechanism to suppress auditory processing. Overall, these preliminary results provide initial evidence that the mPFC exerts a direct, context-dependent functional modulation on the AC.