Depression is a common psychiatric symptom in cerebral small vessel disease (CSVD), which has a certain relationship with impairment of cognitive function and can significantly increase the mortality and morbidity of CSVD patients. The occurrence of CVSD-associated depression is less related to psychological stress, but is associated with the impairment of the brain's emotional circuit. This article reviewed the correlation between the imaging features of CVSD and the occurrence and development of depression in recent years, and the neuroimaging mechanism of depression associated with CVSD. Many literatures have shown that deep white matter hyperintensities and asymptomatic lacunar infarction in the basal ganglia are independent risk factors for depression in CSVD, and the reduction of local brain volume is associated with depression. The neuroimaging mechanism of depression associated with CSVD suggests that the occurrence of depressive symptoms is related to the neural circuits in the lobar cortex-subcortical limbic area. These findings provide clues for exploring the neuropathological mechanisms and specific treatment methods of depression associated with CVSD.

OBJECTIVE To study the effects of isoliquiritigenin （ISL） regulating gut microbiota and repairing gut barrier function in model mice with non-alcoholic fatty liver disease （NAFLD）， and to clarify its mechanism for improving NAFLD. METHODS Thirty male C57BL/6J mice were randomly divided into the normal （ultrapure water）， model group （ultrapure water）， ISL group （100 mg/kg）， with 10 mice in each group. Model group and ISL group were fed with high-fat diet for 19 weeks to establish NAFLD model； at the same time， the mice were given relevant medicine/ultrapure water intragastrically. The changes of body weight in mice were recorded， and liver index， white fat index and brown fat index were calculated. The pathological changes of liver tissue and colon tissue as well as lipid accumulation were observed in mice. The levels of total cholesterol （TC）， triglyceride （TG）， aspartate aminotransferase （AST） and alanine aminotransferase （ALT） E-mail：xiangshj3@mail.sysu.edu.cn in serum or liver were measured； the serum levels of interleukin-6 （IL-6）， IL-1β and tumor necrosis factor-α （TNF-α） and the levels of IL-6， IL-1β and TNF-α mRNA expression in liver tissue were detected. Fecal samples underwent 16S rDNA sequencing analysis， and the effects of ISL on gut microbiota structure of mice were investigated. The expressions of gut mucosal barrier-related proteins （Claudin-4， Occludin and ZO-1） were determined in the colon tissue of mice. RESULTS Compared with model group， the body weight， liver index， the levels of TC in liver tissue and serum， the levels of AST and ALT in serum， the levels of IL-6， IL-1β and TNF-α in serum， and the mRNA expression of TNF-α in liver tissue were all decreased significantly in ISL group， while brown fat index was increased significantly. The inflammation and damage of liver tissue were significantly improved， and the NAFLD activity score and the proportion of lipid staining area were significantly reduced （P＜0.05）. ISL could significantly up-regulate the relative abundance of beneficial microbiota （norank_f_Muribaculaceae， Odoribacter， Ruminiclostridium， etc.） and the expressions of intestinal barrier function- related proteins， but could significantly down-regulate the relative abundance of harmful bacteria （Desulfovibrio， norank_f_Lachnospiraceae， unclassified_p_Firmicutes）， and could repair intestinal barrier. CONCLUSIONS ISL could significantly delay the progress of NAFLD， the mechanism of which may be associated with regulating gut microbiota and improving gut barrier function.

Activation of the heart normally begins in the sinoatrial node (SAN). Electrical impulses spontaneously released by SAN pacemaker cells (SANPCs) trigger the contraction of the heart. However, the cellular nature of SANPCs remains controversial. Here, we report that SANPCs exhibit glutamatergic neuron-like properties. By comparing the single-cell transcriptome of SANPCs with that of cells from primary visual cortex in mouse, we found that SANPCs co-clustered with cortical neurons. Tissue and cellular imaging confirmed that SANPCs contained key elements of glutamatergic neurotransmitter system, expressing genes encoding glutamate synthesis pathway (Gls), ionotropic and metabotropic glutamate receptors (Grina, Gria3, Grm1 and Grm5), and glutamate transporters (Slc17a7). SANPCs highly expressed cell markers of glutamatergic neurons (Snap25 and Slc17a7), whereas Gad1, a marker of GABAergic neurons, was negative. Functional studies revealed that inhibition of glutamate receptors or transporters reduced spontaneous pacing frequency of isolated SAN tissues and spontaneous Ca