Effect of high-intensity interval exercise on depression-related behavior in mice / 生理学报

This paper was aimed to clarify the effect of high-intensity interval training (HIIT) on depression. Animal running platforms were used to establish HIIT exercise models, depression models were prepared by chronic unpredictable mild stress (CUMS), and depression-related behaviors were detected by behavioral experiments. The results showed that HIIT exercise improved depression-related behavior in CUMS model mice. Western blot and ELISA results showed that in the hippocampus, medial prefrontal cortex (mPFC) and amygdala of the CUMS model mice, glucocorticoid receptor (GR) protein expression was down-regulated, and the content of tumor necrosis factor α (TNF-α) was increased, compared with those in the control group, whereas HIIT exercise could effectively reverse these changes in CUMS model mice. These results suggest that HIIT exercise can exert antidepressant effect, which brings new ideas and means for the clinical treatment of depressive diseases.

Projections from Infralimbic Cortex to Paraventricular Thalamus Mediate Fear Extinction Retrieval / 神经科学通报·英文版

The paraventricular nucleus of the thalamus (PVT), which serves as a hub, receives dense projections from the medial prefrontal cortex (mPFC) and projects to the lateral division of central amygdala (CeL). The infralimbic (IL) cortex plays a crucial role in encoding and recalling fear extinction memory. Here, we found that neurons in the PVT and IL were strongly activated during fear extinction retrieval. Silencing PVT neurons inhibited extinction retrieval at recent time point (24 h after extinction), while activating them promoted extinction retrieval at remote time point (7 d after extinction), suggesting a critical role of the PVT in extinction retrieval. In the mPFC-PVT circuit, projections from IL rather than prelimbic cortex to the PVT were dominant, and disrupting the IL-PVT projection suppressed extinction retrieval. Moreover, the axons of PVT neurons preferentially projected to the CeL. Silencing the PVT-CeL circuit also suppressed extinction retrieval. Together, our findings reveal a new neural circuit for fear extinction retrieval outside the classical IL-amygdala circuit.