Dorsal-ventral distinction of chronic stress-induced electrophysiological alterations in the rat medial prefrontal cortex

Abstract

Chronic stress causes neuronal adaptation and maladaptation in the widespread brain regions including the prefrontal cortex (PFC) and limbic structures, resulting in cognitive and affective dysfunctions. In this study, we examined the impacts of chronic stress on functional interaction between the medial PFC and limbic structures in rats. In vivo electrophysiological recordings in rats exposed to chronic stress unveiled disturbance of correlated local field potential activity between the PFC and limbic structures as well as impairment of synaptic plasticity induction in the limbic-PFC pathways. However, these stress-induced alterations in limbic-PFC interaction were distinct along with the dorsal-ventral axis within the PFC, with greater stress vulnerability in the dorsal than the ventral PFC, such that alterations in the dorsal PFC became evident with much shorter duration of repeated stress exposure than those occurring in the ventral PFC. In agreement with the stress-induced alterations in limbic-PFC interaction, spike firing patterns of neurons in the dorsal and ventral PFC were also differently modulated by chronic stress. These results suggest that chronic stress produces heterogeneous cellular and neural network adaptation and maladaptation within the PFC that affect limbic information integration mechanisms.