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The medial prefrontal cortex (mPFC) sends projections to numerous brain regions and is believed to play a significant role in depression and anxiety. One of the key downstream targets of the mPFC, the lateral habenula (LHb), is essential for chronic stress (CS)-induced depressive and anxiety-like behaviors. Nevertheless, whether the mPFC-LHb pathway mediates the co-occurrence of depression and anxiety and the underlying mechanism remain incompletely understood. Here, using chemogenetics, we first determined that activation of LHb-projecting mPFC neurons is essential for the development of depressive and anxiety-like behaviors induced by CS. Subsequently, we identify the extent and distribution of LHb-projecting neurons originating from the mPFC subregion. Through circuit-specific in vivo fiber photometry, we found that Ca2+activity in dorsal mPFC (dmPFC) axon terminals within the LHb was increased during exposure to stressful and anxiety-related stimuli, highlighting the potential role of LHb-projecting dmPFC neurons in conveying stressful and anxiety-related information to the LHb. Finally, we observed that activation of both LHb-projecting dmPFC neurons and their postsynaptic counterparts in the LHb was necessary for CS-induced depressive and anxiety-like behaviors. Overall, this study provides multiple lines of evidence demonstrating that activation of the dmPFC-LHb pathway is a crucial neural circuitry for CS-induced depressive and anxiety-like behaviors.

A silicon carbide (SiC) trench MOSFET featuring an adjustable P-region potential (AP-TMOS) is proposed and investigated to improve high frequency and short-circuit performance in this article. A P/N-base layer is embedded in the trench bottom to introduce a P-region portion at the trench corner. The P-region is at a floating potential due to the hole barrier formed in the fully depleted P-base during ON-state conduction of AP-TMOS, and P-region is grounded by the undepleted region of the P-base during OFF-state operation. Compared with the conventional SiC trench MOSFET (C-TMOS), AP-TMOS shows about 23% reduction of the specific ON-resistance because of the shrinkage of JFET depletion layer caused by the floating P-region. Furthermore, the Miller capacitance and gate–drain charge of AP-TMOS are 4.7 pF/cm2 and 51.1 nC/cm2, which are improved by about 2.4 and 1.7 times compared with C-TMOS owing to the reduced overlapping area between gate and drain contact. The short-circuit withstand time of the proposed TMOS with the adjustable P-region potential increases from 4 to $6~\mu \text{s}$ under 800-V dc bus voltage in comparison with C-TMOS. Finally, an analytical model for the hole barrier height has been discussed for AP-TMOS.

In this letter, a novel SiC trench MOSFET with integrated auto-adjust source-potential region (AS-TMOS) is proposed and investigated to suppress switching oscillation and reduce turn-off switching loss. The auto-adjust source-potential region, consists of a lightly doped P-base and heavy doped P-shield wrapped around the stepped thick-oxide gate trench, effectively modulates turn-off dV/dt by changing gate-to-drain capacitance ( ${C}_{\text {gd}}{)}$ . Under low applied voltage, a lower ${C}_{\text {gd}}$ is achieved because the deep source-potential region collects the electric field lines that originally contributed to gate-to-drain capacitance. Whereas, the ${C}_{\text {gd}}$ increases more rapidly under high applied voltage due to the source-potential region shrinkage induced by the fully depleted P-base. AS-TMOS under 10 nH stray inductance shows a 28% and 17% reduction of surge voltage and turn-off loss when compared with conventional SiC trench MOSFET (C-TMOS), thus reducing the EMI noise. Furthermore, the short circuit withstanding time of AS-TMOS increases from $2~\mu \text{s}$ to $4.5~\mu \text{s}$ under 800 V DC bus voltage in comparison with C-TMOS owing to the reduction of the peak short circuit current caused by the deep source-potential region.