Purpose: Gut microbiota affects various physiological functions in the host and has crucial effects on the nervous system. There is increasing evidence of a correlation between gut microbiota and depression; however, the mechanisms underlying the regulation of depression-like behavior by gut microbiota remain unclear. In this study, we assessed the regulatory mechanism of gut microbiota on depression-like behavior in rats. Methods: We transplanted fecal microbiota obtained from patients with depression and healthy individuals into germ-free (GF) rats (n=18) through fecal microbiota transplantation technology. Next, we assessed the affective behavior in the rats using the forced swimming test and a sucrose preference test. We used enzyme-linked immunosorbent assay (ELISA) to determine the hippocampal levels of 5-hydroxytryptamine (5-HT), dopamine (DA), and noradrenaline (NE) and the serum levels of corticosterone (CORT), adrenocorticotropic hormone (ACTH), corticotropin-releasing hormone (CRH), tumor necrosis factor-α (TNFα), interferon-γ (IFN-γ), interleukin-6 (IL-6), interleukin-1 (IL-1), interleukin-1 (IL-4), and interleukin-1 (IL-10). The mitochondrial morphology of small intestinal epithelial cells was observed through transmission electron microscopy. Results: Rats that received fecal microbiota from patients with depression (depression microbiota) exhibited depression-like behavior. They presented decreased levels of hippocampal neurotransmitters, serum CORT levels, and anti-inflammatory cytokine levels, as well as increased ACTH, CRH, and serum levels of multiple pro-inflammatory cytokines. Observation of the mitochondria ultrastructure showed damaged mitochondria in the intestinal epithelial cells, significant endoplasmic reticulum expansion, and border aggregation of nuclear chromatin. Conclusion: Our findings suggested that the depression-like behaviors induced by the depression microbiota through the neuroendocrine-immune-mitochondrial pathway, which were associated with neuroendocrine disorders, inflammatory responses, and mitochondrial damage.

Objective To clarify the effectiveness and mechanism of the Chinese herbal formula Xingpi Kaiyu Fang (XPKYF) which is composed of American ginseng (Xi-Yang-shen), Radix curcumae (Yu-Jin), Acori tatarinowii rhizoma (Shi-Chang-pu), and Hypericum perforatum (Guan-Ye-lian-qiao) in depressed rats. Methods The rat model of depression was established by chronic unpredictable mild stress (CUMS) method for 6 weeks. Rats were randomly divided into six groups: control group, CUMS group, CUMS+XPKYF (3.6g/kg/d, 7.2g/kg/d, 14.4g/kg/d) groups, and CUMS+sertraline (4.5mg/kg/d) group. The sucrose preference test and the forced swimming test were performed to assess the rats' depression behavior. Mitochondrial ultrastructure was observed by transmission electron microscope and adenosine triphosphate (ATP) content, sodium potassium ATPase (Na/K-ATPase) activity, and mitochondrial respiratory chain complexes activities in hippocampus and gastrocnemius muscle were measured at the 14th and 42nd day. Results Rats subjected to six weeks of CUMS exhibited decreased sucrose preference ratio and prolonged immobility time. CUMS reduced ATP content in hippocampus, decreased Na/K-ATPase activity and respiratory chain complex I, III, and IV activities in hippocampus and gastrocnemius muscle, and damaged mitochondrial ultrastructure of hippocampus and gastrocnemius muscle. XPKYF at 14.4g/kg, the efficacy trend of which was better than the other drug groups, could prevent the stress-induced depressed behavior changes, inhibit the decrease of Na/K-ATPase activity in hippocampus, inhibit the decrease of respiratory chain complex III activities in hippocampus and gastrocnemius muscle, and protect mitochondria from ultrastructural damage. Conclusions Energy deficiency and damaged mitochondrial ultrastructure were found in hippocampus and gastrocnemius muscle of depressed rats established by CUMS. XPKYF could partly reverse alterations in ATP, Na/K-ATPase, and respiratory chain complexes of hippocampus and gastrocnemius muscle and protect mitochondria from ultrastructural damage. This provides another experimental evidence for the clinical application of XPKYF in the treatment of depression.

Magnetostrictive bioinspired whisker is a new kind of sensor that can realize tactile and flow sensing by utilizing magnetoelastic effect. e sensitivity is a key technical indicator of whisker sensor. e paper presented a new magnetostrictive whisker based on Galfenol cantilever beam, as well as its operation principle. en, the static and dynamic sensitivity of the whisker sensor was investigated by using a self-made experimental system. e results illustrated that the proposed sensor has a high sensitivity. Its static sensitivity is 2.2 mV/mN. However, its dynamic sensitivity depends on the vibration frequency. When working at the natural frequency of the cantilever beam, the dynamic sensitivity performs an obvious increase-1.3 mV/mN at 3.5 Hz (the first-order natural frequency) and 2.1 mV/mN at 40 Hz (the second-order natural frequency), respectively.

Background and objectivesThe treatment of somatic symptoms of depression is a medical problem nowadays. More and more evidences show that oxidative stress and mitochondrial dysfunction may be an important pathogenesis of depression and are closely related to somatic symptoms. Currently, studies on oxidative stress and mitochondrial function are mostly concentrated in the brain, with less attention paid to peripheral tissues, and classical SSRIs are not direct antioxidants in treatment. XingPiJieYu (XPJY) Decoction is one of the most widely used clinical formulas of traditional Chinese medicine. Our study aims to exploring whether it has antioxidative and mitochondrial effects on intracerebral and extra brain tissue. Materials and methodsThe rat model of depression was established by CUMS (chronic unpredictable mild stress, CUMS) for 6 weeks. They were randomly divided into six groups: control group, CUMS group, CUMS+XPJY (3.6g/kg/d, 7.2g/kg/d, 14.4g/kg/d) groups, CUMS+ sertraline (4.5mg/kg/d) group. We used sucrose preference test and forced swimming test to verify the success of the depression model. The contents of CK and SDH in orbital blood were measured weekly as well as the following assay index were measured on 14 th day and 42 th day, including MDA, ATP and mtDNA in hippocampus, prefrontal cortex, liver, small intestine and gastrocnemius muscle. ResultsAt the 14 th day, the sucrose preference ratio was decreased. Besides, the immobility time prolonged at the 42 nd day. CUMS increased MDA content in hippocampus, prefrontal cortex and gastrocnemius muscle, but decreased mtDNA content in prefrontal cortex at the 14 th day; CUMS decreased serum SDH level at the 35 th day, but elevated serum CK level at the 42 nd day; CUMS increased MDA content in hippocampus, prefrontal cortex, liver and gastrocnemius muscle, while decreased ATP and mtDNA content in hippocampus, prefrontal cortex, liver, small intestine and gastrocnemius muscle at the 42 nd day. XPJY decoction at 14.4g/kg, the efficacy trend of which was better than the other drug groups, could prevent the depressive behavior caused by CUMS, reduce the serum CK content and the MDA content of the tissues mentioned above, and increase serum SDH content as well as ATP, mtDNA content in tissues.XPJY Decoction, a Chinese herbal medicine, which has been confirmed to improve depressive behavior, increase serum 5-HT, decrease serum corticosterone, decrease inflammatory factors in serum and hippocampus, increase the expression of cAMP, PKA, CREB and BDNF in hippocampus of CUMS rats [21][22][23][24].