Aberrant increased GABAergic neuronal activity in postrhinal cortex impairs spatial memory.

The postrhinal cortex (POR) in rodents is homologous with the primate parahippocampal cortex (PHC), and has been shown to play a crucial role in spatial and object recognition memory functions. Our previous study identified that POR glutamatergic neurons are specifically regulate spatial memory retrieval. However, the function of POR γ-aminobutyric acidergic (GABAergic) neurons in spatial and object recognition memory remains to be elucidated. In this study, we first confirmed that the POR contains plenty of GABAergic neurons. Then we determined that hyperactivity of POR GABAergic neurons impairs spatial memory, without affecting object recognition memory. We observed that hyperactivity of POR GABAergic neurons might suppress surrounding neuronal activity, which may lead to impairment of spatial memory. These findings add to our understanding of the function and dysfunction of POR GABAergic neurons in spatial memory and provide new insights for future research on diseases related to spatial memory decline.