The hippocampal to prefrontal cortex circuit in mice: a promising electrophysiological signature in models for psychiatric disorders.

Interaction between the hippocampus and the medial prefrontal cortex (mPFC) has been identified as a key target in several neuropsychiatric disorders. However, the hippocampus-mPFC (H-PFC) pathway has not been outlined in mice, which are increasingly the leading choice for new animal models for neurological disorders. Our results, establish the existence of a topographical, monosynaptic pathway originating exclusively from the ventral CA1 and subiculum to the mPFC. Functional connectivity of the H-PFC pathway, examined in vivo through field potential recordings in the prelimbic mPFC after high-frequency stimulation of the hippocampal outflow, demonstrates an induction of a significant long lasting long-term potentiation, which is stable for at least one hour and strongly impaired by exposure to acute stress. Given that stress exposure is known to have serious detrimental effects on prefrontal cortical functioning and is considered a major risk factor for several neuropsychiatric disorders, the present study provides a crucial animal model of neural interaction and response to environmental stress which could lend itself to the study of disruption of brain circuits and test for potential drug candidates.