Physical exercise can alleviate some of the schizophrenia symptoms in patients, the mechanisms, however, are still unclear. To investigate whether the GABAergic interneuron involved in the therapeutic effect of treadmill running on schizophrenia, the parvalbumin (PV)-positive GABAergic interneurons in the dentate gyrus (DG) was specifically activated or abolished and the effects were evaluated. In the MK801induced schizophrenia-like animal model, we found:(1) Treadmill running rescued the schizophrenia-related behavioral phenotypes, promoted the adult hippocampal neurogenesis, and increased the dendrite number and complexity of newborn neurons. (2) Treadmill running increased the number of PV-positive interneurons in the DG; genetic ablation of these interneurons reduced adult neurogenesis and abolished the effect of treadmill running on the schizophrenia-related behaviors. Consistently, chemogenetic activation of these interneurons improved neurogenesis and alleviated the schizophrenia-related behaviors. These results suggest a pivotal role of PV-positive interneuron-mediated adult neurogenesis in exercise. (3) However, schizophreniarelated behavioral phenotypes and adult neurogenesis in the DG could still be reversed by exercise after specifically knocking out the schizophrenia-related gene ErbB4 in PV interneurons, as a means to reduce their GABA release. These results suggest that activation of PV interneurons in the DG is sufficient for treadmill running to reverse schizophrenia-like phenotypes.

Recent studies have shown exercise is effective for adult hippocampus neurogenesis and memory. However, the molecular mechanism of exercise is unclear. In this study, AG1478, an ErbB4 inhibitor, was used to explore the involvement of ErbB4 receptors. Four weeks post-running, cognitive impairment was analyzed using T-maze, Morris water maze (MWM) and contextual fear discrimination learning tests, followed by histological assessment of the proliferation and survival of hippocampal neurons using Ki67, NeuN and BrdU immunostaining respectively. Expression of total and phosphate ErbB4 protein level was evaluated by Western blotting. The results showed that AG1478 significantly impaired the performances in T-maze and MWM (spatial learning and memory), contextual fear conditioning and discrimination learning paradigm (non-spatial working and reference memory), enhanced neurogenesis loss, downregulated the expression of p-ErbB4 and total ErbB4 protein, which could be reversed by running. Taken together, our study suggested that running ameliorates cognitive impairment and neurogenesis via ErbB4 signaling.

Recent studies have shown exercise is effective for adult hippocampus neurogenesis and memory. However, the molecular mechanism of exercise is unclear. In this study, AG1478, an ErbB4 inhibitor, was used to explore the involvement of ErbB4 receptors. Four weeks post-running, cognitive impairment was analyzed using T-maze, Morris water maze (MWM) and contextual fear discrimination learning tests, followed by histological assessment of the proliferation and survival of hippocampal neurons using Ki67, NeuN and BrdU immunostaining respectively. Expression of total and phosphate ErbB4 protein level was evaluated by Western blotting. The results showed that AG1478 significantly impaired the performances in T-maze and MWM (spatial learning and memory), contextual fear conditioning and discrimination learning paradigm (non-spatial working and reference memory), enhanced neurogenesis loss, downregulated the expression of p-ErbB4 and total ErbB4 protein, which could be reversed by running. Taken together, our study suggested that running ameliorates cognitive impairment and neurogenesis via ErbB4 signaling.

In our previous study, we found parvalbumin (PV) positive GABAergic interneurons in DG were critical for exercise to increase adult neurogenesis and to improve schizophrenia related phenotypes in mouse model. How exercise affects PV interneuron function needs to be further investigated. In this study, AG1478, an ErbB4 inhibitor, was used to explore its molecular mechanisms as a pharmacological means. Four weeks post-running with AG1478, we found: (1). AG1478 significantly impaired the performances in T-maze, Morris water maze (MWM, spatial learning and memory), contextual fear conditioning and discrimination learning paradigm (non-spatial working and reference memory). (2).AG1478 enhanced neurogenesis loss, downregulated the expression of p-ErbB4 and total ErbB4 protein, (3) AG1478 decreased the intracellular Ca2+ levels in PV neurons which could be reversed by running. Taken together, our study suggested that Treadmill running regulates adult neurogenesis, spatial and non-spatial learning, PV neuron activity by ErbB4 signaling.