Cell Type-Specific Modulation of Acute Itch Processing in the Anterior Cingulate Cortex.

Despite remarkable progress in understanding the fundamental bases of itching, its cortical mechanisms remain poorly understood. Herein, the causal contributions of defined anterior cingulate cortex (ACC) neuronal populations to acute itch modulation in mice are established. Using cell type-specific manipulations, the opposing functions of ACC glutamatergic and GABAergic neurons in regulating acute itching are demonstrated. Photometry studies indicated that ACC glutamatergic neurons are activated during scratching induced by both histamine and chloroquine, whereas the activation pattern of GABAergic neurons is complicated by GABAergic subpopulations and acute itch modalities. By combining cell type- and projection-specific techniques, a thalamocortical circuit is further identified from the mediodorsal thalamus driving the itch-scratching cycle related to histaminergic and non-histaminergic itching, which is contingent on the activation of postsynaptic parvalbumin-expressing neurons in the ACC. These findings reveal a cellular and circuit signature of ACC neurons orchestrating behavioral responses to itching and may provide insights into therapies for itch-related diseases.

Novel Polyurethane Based, Fully Flexible, High-Performance Piezoresistive Sensor for Real-Time Pressure Monitoring.

Flexible piezoresistive pressure sensors are garnering substantial attention, in line with advancements in biointegrated and wearable electronics. However, a significant portion of piezoresistive pressure sensors suffer from the trade-off between sensitivity and pressure range. Moreover, the current piezoresistive sensors generally rely on a rigid metallic electrode, severely deteriorating their long-term durability. Herein, a fully flexible piezoresistive sensor coupling polyurethane (PU) based electrode and active sensing element is proposed to circumvent the aforementioned problems. By rationally regulating the double-permeable conductive networks within the PU matrix, an elastomeric electrode and sensing element are implemented, respectively. The assembled heterostructured configurations enable impressive sensitivity up to 7.023 kPa-1, broad pressure detection (up to 420 kPa), an ultralow pressure sensing limit (0.1 Pa), and extraordinary operation stability over 80000 cyclic pressings along with fast response/relaxation times (60 ms/80 ms). Additionally, the fully flexible sensor is capable of both real-time detection of physiological signals and mimicking keyboards, implying its viability as a high-performance pressure sensor.

Prenatal disruption of blood-brain barrier formation via cyclooxygenase activation leads to lifelong brain inflammation.

Gestational maternal immune activation (MIA) in mice induces persistent brain microglial activation and a range of neuropathologies in the adult offspring. Although long-term phenotypes are well documented, how MIA in utero leads to persistent brain inflammation is not well understood. Here, we found that offspring of mothers treated with polyriboinosinic­polyribocytidylic acid [poly(I:C)] to induce MIA at gestational day 13 exhibit blood­brain barrier (BBB) dysfunction throughout life. Live MRI in utero revealed fetal BBB hyperpermeability 2 d after MIA. Decreased pericyte­endothelium coupling in cerebral blood vessels and increased microglial activation were found in fetal and 1- and 6-mo-old offspring brains. The long-lasting disruptions result from abnormal prenatal BBB formation, driven by increased proliferation of cyclooxygenase-2 (COX2; Ptgs2)-expressing microglia in fetal brain parenchyma and perivascular spaces. Targeted deletion of the Ptgs2 gene in fetal myeloid cells or treatment with the inhibitor celecoxib 24 h after immune activation prevented microglial proliferation and disruption of BBB formation and function, showing that prenatal COX2 activation is a causal pathway of MIA effects. Thus, gestational MIA disrupts fetal BBB formation, inducing persistent BBB dysfunction, which promotes microglial overactivation and behavioral alterations across the offspring life span. Taken together, the data suggest that gestational MIA disruption of BBB formation could be an etiological contributor to neuropsychiatric disorders.

Parvalbumin Neurons in Zona Incerta Regulate Itch in Mice.

Pain and itch are intricately entangled at both circuitry and behavioral levels. Emerging evidence indicates that parvalbumin (PV)-expressing neurons in zona incerta (ZI) are critical for promoting nocifensive behaviors. However, the role of these neurons in itch modulation remains elusive. Herein, by combining FOS immunostaining, fiber photometry, and chemogenetic manipulation, we reveal that ZI PV neurons act as an endogenous negative diencephalic modulator for itch processing. Morphological data showed that both histamine and chloroquine stimuli induced FOS expression in ZI PV neurons. The activation of these neurons was further supported by the increased calcium signal upon scratching behavior evoked by acute itch. Behavioral data further indicated that chemogenetic activation of these neurons reduced scratching behaviors related to histaminergic and non-histaminergic acute itch. Similar neural activity and modulatory role of ZI PV neurons were seen in mice with chronic itch induced by atopic dermatitis. Together, our study provides direct evidence for the role of ZI PV neurons in regulating itch, and identifies a potential target for the remedy of chronic itch.

Ginsenoside Rb1 induces a pro-neurogenic microglial phenotype via PPARγ activation in male mice exposed to chronic mild stress.

BACKGROUND: Anti-inflammatory approaches are emerging as a new strategy for the treatment of depressive disorders. Ginsenoside Rb1 (GRb1), a major component of Panax ginseng, can inhibit inflammatory cascade and alleviate depressive-like behaviors. Microglia can promote or inhibit adult hippocampal neurogenesis according to their functional phenotypes. Here, we examine whether GRb1 may exert antidepressant effects by promoting a pro-neurogenic phenotype of microglia and thereby increasing neurogenesis. METHODS: The antidepressant effects of GRb1 or the licensed antidepressant imipramine (IMI) were assessed in chronic mild stress (CMS)-exposed male mice. The depressive-like behaviors of mice were evaluated by sucrose preference test, forced swimming test (FST), and tail suspension test (TST). The microglial phenotypes were identified by pro- and anti-inflammatory cytokine expression and morphological properties, analyzed by RT-qPCR, western blotting, and immunofluorescence staining. The effect of GRb1-treated microglia on adult hippocampal neurogenesis in vivo and in vitro was detected using immunofluorescence staining. RESULTS: Behavioral assessment indicated that GRb1 or IMI treatment alleviated depressive-like behaviors in CMS-exposed mice. Immunofluorescence examination demonstrated that GRb1 induced a pro-neurogenic phenotype of microglia via activating PPARγ in vivo and in vitro, which were effectively reversed by the PPARγ inhibitor GW9662. In addition, GRb1-treated microglia increased the proliferation and differentiation of neural precursor cells. CONCLUSIONS: These findings demonstrated that GRb1 alleviated depressive-like behaviors of CMS-exposed male mice mainly through PPARγ-mediated microglial activation and improvement of adult hippocampus neurogenesis.

IL4-driven microglia modulate stress resilience through BDNF-dependent neurogenesis.

Adult neurogenesis in the dentate gyrus of the hippocampus is regulated by specific microglia groups and functionally implicated in behavioral responses to stress. However, the role of microglia in hippocampal neurogenesis and stress resilience remains unclear. We identified interleukin 4 (IL4)-driven microglia characterized by high expression of Arg1, which is critical in maintaining hippocampal neurogenesis and stress resistance. Decreasing Arg1+ microglia in the hippocampus by knocking down the microglial IL4R suppressed hippocampal neurogenesis and enhanced stress vulnerability. Increasing Arg1+ microglia in the hippocampus by enhancing IL4 signaling restored hippocampal neurogenesis and the resilience to stress-induced depression. Brain-derived neurotrophic factor (BDNF) was found necessary for the proneurogenesis effects of IL4-driven microglia. Together, our findings suggest that IL4-driven microglia in the hippocampus trigger BDNF-dependent neurogenesis responding to chronic stress, helping protect against depressive-like symptoms. These findings identify the modulation of a specific microglial phenotype as a treatment strategy for mood disorders.

Brain-Type Glycogen Phosphorylase Is Crucial for Astrocytic Glycogen Accumulation in Chronic Social Defeat Stress-Induced Depression in Mice.

Astrocytic glycogen plays an important role in brain energy metabolism. However, the contribution of glycogen metabolism to stress-induced depression remains unclear. Chronic social defeat stress was used to induce depression-like behaviors in mice, assessed with behavioral tests. Glycogen concentration in the medial prefrontal cortex (mPFC) and the expression of key enzymes of the glycogen metabolism were investigated using Western blots, immunofluorescent staining, electron microscopy, and biochemical assays. Stereotaxic surgery and viral-mediated gene transfer were applied to knockdown or overexpress brain-type glycogen phosphorylase (PYGB) in the mPFC. The glycogen content increased in the mPFC after stress. Glycogenolytic dysfunction due to inactivation of PYGB was responsible for glycogen accumulation. Behavioral tests on astrocyte-specific PYGB overexpression mice showed that augmenting astrocytic PYGB reduces susceptibility to depression when compared with stress-susceptible mice. Conversely, PYGB genetic down-regulation in the mPFC was sufficient to induce glycogen accumulation and depression-like behaviors. Furthermore, PYGB overexpression in the mPFC decreases susceptibility to depression, at least partially by rescuing glycogen phosphorylase activity to maintain glycogen metabolism homeostasis during stress. These findings indicate that (1) glycogen accumulation occurs in mice following stress and (2) glycogenolysis reprogramming leads to glycogen accumulation in astrocytes and PYGB contributes to stress-induced depression-like behaviors. Pharmacological tools acting on glycogenolysis might constitute a promising therapy for depression.

Pioglitazone alleviates maternal sleep deprivation-induced cognitive deficits in male rat offspring by enhancing microglia-mediated neurogenesis.

Maternal sleep disturbance in pregnancy causes cognitive impairments and emotional disorders in offspring. Microglia-mediated inflammatory processes contribute to prenatal stress-induced neurodevelopmental deficits. Peroxisome proliferator-activated receptor gamma (PPARγ) activation underlies the switching of microglial activation phenotypes, which has emerged as a pharmacological target for regulating neuroinflammatory responses in the treatment of neuropsychiatric disorders. Here we investigated the effects of PPARγ-dependent microglial activation on neurogenesis and cognitive behavioral outcomes in male rat offspring exposed to maternal sleep deprivation (MSD) for 72 h from days 18-21 of pregnancy. In the Morris water maze test, male MSD rat offspring needed more time than control offspring to escape to the hidden platform and spent less time in the target quadrant when the hidden platform was removed. In MSD rat offspring, microglial density as determined by immunofluorescence was higher, microglia showed fewer and shorter processes, and neurogenesis in the hippocampus was significantly reduced. Levels of mRNA encoding pro-inflammatory markers IL-6, TNFα, and IL-1ß were higher in male MSD offspring, whereas levels of anti-inflammatory markers Arg1, IL-4, and IL-10 were lower, as was PPARγ expression in the hippocampus. PPARγ activation by pioglitazone (30 mg/kg/day, i.p., 7 d) mitigated these negative effects of MSD, rescuing hippocampal neurogenesis and improving cognitive function. The PPARγ inhibitor GW9662 (1 mg/kg/day, i.p., 7 d) eliminated the effects of pioglitazone. Conditioned medium from pioglitazone-treated microglia promoted proliferation and differentiation of neural progenitor cells. These results suggest that MSD-induced deficits in spatial learning and memory can be ameliorated through PPARγ-dependent modulation of microglial phenotypes.

PVDF-Based Composition-Gradient Multilayered Nanocomposites for Flexible High-Performance Piezoelectric Nanogenerators.

Recently, flexible energy generators with good performance have trigged enormous interest because of their great potential application in developing full flexible self-powered electronics. Herein, we reported a flexible high-performance piezoelectric nanogenerator (PNG) based on composition-gradient multilayered poly(vinylidene fluoride) (PVDF) nanocomposites wherein a novel three-dimensional (3D) carbon-based nanoparticle was employed as the nanofiller. Making use of this novel 3D nanofiller and composition-gradient concept, one can efficiently promote the interfacial coupling effect and induce internal strain inside the PVDF matrix, contributing to dramatically improved piezoelectricity and consequently output performance for PNG. With the excellent output ability, the PNG also demonstrated to be capable of operating in both d33 and d31 modes and possesses high stability as well as durability, confirming its applicability as green power source for full flexible electronic systems.

In Utero Exposure to Citalopram Mitigates Maternal Stress Effects on Fetal Brain Development.

Human epidemiological and animal-model studies suggest that separate exposure to stress or serotonin-selective reuptake inhibitor (SSRI) antidepressants during pregnancy increases risks for neurodevelopmental disorders in offspring. Yet, little is known about the combined effects of maternal stress and SSRIs with regard to brain development in utero. We found that the placenta is highly permeable to the commonly prescribed SSRI (±)-citalopram (CIT) in humans and mice, allowing rapid exposure of the fetal brain to this drug. We investigated the effects of maternal chronic unpredictable stress in mice with or without maternal oral administration of CIT from embryonic day (E)8 to E17. We assessed fetal brain development using magnetic resonance imaging and quantified changes in serotonergic, thalamocortical, and cortical development. In utero exposure to maternal stress did not affect overall fetal brain growth. However, serotonin tissue content in the fetal forebrain was increased in association with maternal stress; this increase was reversed by maternal CIT. In utero exposure to stress increased the numbers of deep-layer neurons in specific cortical regions, whereas CIT increased overall cell numbers without changing the proportions of layer-specific neurons to offset the effects of stress on deep-layer cortical development. These findings suggest that stress and SSRI exposure in utero differentially impact serotonin-dependent fetal neurodevelopment such that CIT reverses key effects of maternal gestational stress on offspring brain development.

Minocycline inhibits microglial activation and alleviates depressive-like behaviors in male adolescent mice subjected to maternal separation.

Exposure to early adversity increases vulnerability to psychiatric disorders in later life. Microglia-mediated inflammation has been linked to psychopathology, so such inflammation may be a target for treating depression. Using a model of depression involving adolescent male C57BL/6J mice subjected to maternal separation, we explored whether using minocycline to mitigate inflammation can alleviate depression-like behaviors. Between postnatal days 1 and 14, male mice were separated from their mothers for 3 h per day. Minocycline (20 mg/kg) was administered intraperitoneally once daily for 2 weeks starting one week after weaning. Then the male mice were subjected to a second stress for 2 weeks. Results from the sucrose preference test, forced swimming test, and open field test showed that maternal separation did not obviously alter behavior of the male mice, but it did increase the risk of depression-like behaviors following a second stress. This increased risk disappeared if minocycline was given preemptively before the second stress. Maternal separation and second stress up-regulated pro-inflammatory markers and down-regulated anti-inflammatory markers in the hippocampus, and they activated microglia and promoted pro-inflammatory transitions in microglia. All these effects were reversed by minocycline. These changes in inflammatory processes correlated with changes in neurogenesis and BDNF expression in the hippocampus. Our results in this mouse model suggest the potential of minocycline for treating psychiatric disorders induced by early adversity.

Maternal immune activation-induced PPARγ-dependent dysfunction of microglia associated with neurogenic impairment and aberrant postnatal behaviors in offspring.

Maternal infection during pregnancy is an important factor involved in the pathogenesis of brain disorders in the offspring. Mounting evidence from maternal immune activation (MIA) animals indicates that microglial priming may contribute to neurodevelopmental abnormalities in the offspring. Because peroxisome proliferator-activated receptor gamma (PPARγ) activation exerts neuroprotective effects by regulating neuroinflammatory response, it is a pharmacological target for treating neurogenic disorders. We investigated the effect of PPARγ-dependent microglial activation on neurogenesis and consequent behavioral outcomes in male MIA-offspring. Pregnant dams on gestation day 18 received Poly(I:C) (1, 5, or 10 mg/kg; i.p.) or the vehicle. The MIA model that received 10 mg/kg Poly(I:C) showed significantly increased inflammatory responses in the maternal serum and fetal hippocampus, followed by cognitive deficits, which were highly correlated with hippocampal neurogenesis impairment in prepubertal male offspring. The microglial population in hippocampus increased, displayed decreased processes and larger soma, and had a higher expression of the CD11b, which is indicative of the M1 phenotype (classical activation). Activation of the PPARγ pathway by pioglitazone in the MIA offspring rescued the imbalance of the microglial activation and ameliorated the MIA-induced suppressed neurogenesis and cognitive impairments and anxiety behaviors. In an in vitro experiment, PPARγ-induced M2 microglia (alternative activation) promoted the proliferation and differentiation of neural precursor cells. These results indicated that the MIA-induced long-term changes in microglia phenotypes were associated with hippocampal neurogenesis and neurobehavioral abnormalities in offspring. Modulation of the microglial phenotypes was associated with a PPARγ-mediated neuroprotective mechanism in the MIA offspring and may serve as a potential therapeutic approach for prenatal immune activation-induced neuropsychiatric disorders.

Correction to "Structure Based Design of Non-Natural Peptidic Macrocyclic Mcl-1 Inhibitors".

[This corrects the article DOI: 10.1021/acsmedchemlett.6b00464.].

Salvianolic acid B promotes microglial M2-polarization and rescues neurogenesis in stress-exposed mice.

Although accumulating evidence suggests that activated microglia are associated with deficits in neurogenesis and contribute to the physiopathology of major depressive disorder, the role of microglia in treating depression remains poorly understood. Our previous study showed that salvianolic acid (SalB) has the regulation of neuroinflammatory responses and antidepressant-like effects. Here, we hypothesized that SalB's therapeutic effects occur because it modulates microglial phenotypes that are associated with neurogenesis. To test this hypothesis, we treated CMS-exposed C57BL/6 mice with SalB (20mg/kg, intraperitoneally, once daily) for 3weeks and investigated microglial phenotypic profiles and hippocampal neurogenesis. The results showed that the SalB treatment skewed M1 microglial polarization toward M2 activation in the hippocampus and cortex and remedied CMS-induced deficits in hippocampal neurogenesis. SalB (40µM) inhibited LPS-stimulated microglial M1 activation as well as induced M2 activation in vitro, and the cultured microglia with the SalB treatment showed enhanced neural precursor cell proliferation, differentiation, and survival. SalB treatment also ameliorated the depressive-like behaviors of the CMS-treated mice in sucrose preference, forced swimming, and tail suspension tests. These findings suggest a possible antidepressive mechanism for anti-inflammatory agents that is correlated with microglial polarization and hippocampal neurogenesis and which may provide a new microglia-targeted strategy for depression therapy.

Structure Based Design of Non-Natural Peptidic Macrocyclic Mcl-1 Inhibitors.

Mcl-1 is a pro-apoptotic BH3 protein family member similar to Bcl-2 and Bcl-xL. Overexpression of Mcl-1 is often seen in various tumors and allows cancer cells to evade apoptosis. Here we report the discovery and optimization of a series of non-natural peptide Mcl-1 inhibitors. Screening of DNA-encoded libraries resulted in hit compound 1, a 1.5 µM Mcl-1 inhibitor. A subsequent crystal structure demonstrated that compound 1 bound to Mcl-1 in a ß-turn conformation, such that the two ends of the peptide were close together. This proximity allowed for the linking of the two ends of the peptide to form a macrocycle. Macrocyclization resulted in an approximately 10-fold improvement in binding potency. Further exploration of a key hydrophobic interaction with Mcl-1 protein and also with the moiety that engages Arg256 led to additional potency improvements. The use of protein-ligand crystal structures and binding kinetics contributed to the design and understanding of the potency gains. Optimized compound 26 is a <3 nM Mcl-1 inhibitor, while inhibiting Bcl-2 at only 5 µM and Bcl-xL at >99 µM, and induces cleaved caspase-3 in MV4-11 cells with an IC50 of 3 µM after 6 h.

The antidepressant-like effects of pioglitazone in a chronic mild stress mouse model are associated with PPARγ-mediated alteration of microglial activation phenotypes.

BACKGROUND: Discoveries that microglia-mediated neuroinflammation is involved in the pathological process of depression provided a new strategy for novel antidepressant therapy. Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor regulating inflammation and microglial polarization and, therefore, a potential target for resolving depressive disorders. Our hypothesis was that antidepressant effects could be achieved through anti-inflammatory and neuroprotective activities by PPARγ-dependent microglia-modulating agents. METHODS: Chronic mild stress (CMS) treatment was performed on C57BL/6 mice for 6 weeks. After 3 weeks with the CMS procedure, depressive-like behaviors were evaluated by sucrose preference (SP), tail suspension test (TST), forced swimming test (FST), and locomotor activity. Pioglitazone was administered intragastrically once per day for 3 weeks at different doses. Neuroinflammatory cytokines were determined by real time-PCR (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and western blot. The activated microglial state was confirmed by immunohistochemistry. N9 microglial cells were subjected to lipopolysaccharide, pioglitazone, and GW9662 to discuss the phenotype of activated microglia by RT-PCR, ELISA, and western blot. RESULTS: It was demonstrated that the PPARγ agonist pioglitazone (2.5 mg/kg) ameliorated depression-like behaviors in CMS-treated mice, as indicated by body weight (BW), the SP test, the FST, and the TST. The amelioration of the depression was blocked by the PPARγ antagonist GW9662. The expression of M1 markers (IL-1ß, IL-6, TNFα, iNOS, and CCL2) increased, and the gene expression of M2 markers (Ym1, Arg1, IL-4, IL-10, and TGFß) decreased in the hippocampus of the stress-treated mice. Pioglitazone significantly inhibited the increased numbers and morphological alterations of microglia in the hippocampus, reduced the elevated expression of microglial M1 markers, and increased the downgraded expression of microglial M2 markers in C57BL/6 mice exposed to CMS. In an in vitro experiment, pioglitazone reversed the imbalance of M1 and M2 inflammatory cytokines, which is correlated with the inhibition of nuclear factor kB activation and is expressed in LPS-stimulated N9 microglial cells. CONCLUSIONS: We showed that pioglitazone administration induce the neuroprotective phenotype of microglia and ameliorate depression-like behaviors in CMS-treated C57BL/6 mice. These data suggested that the microglia-modulating agent pioglitazone present a beneficial choice for depression.

Salvianolic acid B ameliorates depressive-like behaviors in chronic mild stress-treated mice: involvement of the neuroinflammatory pathway.

AIM: Major depressive disorder (MDD) is a debilitating mental disorder associated with dysfunction of the neurotransmitter-neuroendocrine system and neuroinflammatory responses. Salvianolic acid B (SalB) has shown a variety of pharmacological activities, including anti-inflammatory, antioxidant and neuroprotective effects. In this study, we examined whether SalB produced antidepressant-like actions in a chronic mild stress (CMS) mouse model, and explored the mechanisms underlying the antidepressant-like actions of SalB. METHODS: Mice were subjected to a CMS paradigm for 6 weeks. In the last 3 weeks the mice were daily administered SalB (20 mg·kg(-1)·d(-1), ip) or a positive control drug imipramine (20 mg·kg(-1)·d(-1), ip). The depressant-like behaviors were evaluated using the sucrose preference test, the forced swimming test (FST), and the tail suspension test (TST). The gene expression of cytokines in the hippocampus and cortex was analyzed with RT-PCR. Plasma corticosterone (CORT) and cerebral cytokines levels were assayed with an ELISA kit. Neural apoptosis and microglial activation in brain tissues were detected using immunofluorescence staining. RESULTS: Administration of SalB or imipramine reversed the reduced sucrose preference ratio of CMS-treated mice, and significantly decreased their immobility time in the FST and TST. Administration of SalB significantly decreased the expression of pro-inflammatory cytokines IL-1ß and TNF-α, and markedly increased the expression of anti-inflammatory cytokines IL-10 and TGF-ß in the hippocampus and cortex of CMS-treated mice, and normalized their elevated plasma CORT levels, whereas administration of imipramine did not significantly affect the imbalance between pro- and anti-inflammatory cytokines in the hippocampus and cortex of CMS-treated mice. Finally, administration of SalB significantly decreased CMS-induced apoptosis and microglia activation in the hippocampus and cortex, whereas administration of imipramine had no significant effect on CMS-induced apoptosis and microglia activation in the hippocampus and cortex. CONCLUSION: SalB exerts potent antidepressant-like effects in CMS-induced mouse model of depression, which is associated with the inhibiting microglia-related apoptosis in the hippocampus and the cortex.

Antidepressant-like effects of Sanyuansan in the mouse forced swim test, tail suspension test, and chronic mild stress model.

Natural products have been widely reported as effective therapeutic alternatives for treatment of depression. Sanyuansan is a compound recipe composed of ginseng total saponins, fish oil, and valeriana. The aims of this study were to validate whether Sanyuansan has antidepressant-like effects through acute behavioral tests including the forced swimming test (FST), tail suspension test (TST), locomotor activity test, and chronic mild stress (CMS) mice model of depression. C57BL/6 mice were given oral administration of 30 mg/kg imipramine, Sanyuansan, and saline, respectively. The acute behavioral tests including the TST, FST, and locomotor activity test were done after the administration of drugs for consecutively three times (24 hours, 1 hour, and 0.5 hour prior to the tests). Furthermore, the sucrose preference and the serum corticosterone level of mice in the CMS model were examined. Sanyuansan only at 900 mg/kg markedly reduced immobility time in the TST compared with the saline-treated group of mice. Sanyuansan at doses of 225 mg/kg, 450 mg/kg, and 900 mg/kg significantly reduced immobility time of mice in the FST. Sanyuansan reversed the CMS-induced anhedonia and hyperactivation of the hypothalamus-pituitary-adrenal axis. In addition, our results showed that neither imipramine nor Sanyuansan at any dosage increased spontaneous motor activity. These results suggested that Sanyuansan induced significant antidepressant-like effects in mice in both acute and chronic animal models, which seemed unlikely to be attributed to an increase in locomotor activities of mice, and had no sedative-like effects.

Phenotypic dysregulation of microglial activation in young offspring rats with maternal sleep deprivation-induced cognitive impairment.

Despite the potential adverse effects of maternal sleep deprivation (MSD) on physiological and behavioral aspects of offspring, the mechanisms remain poorly understood. The present study was intended to investigate the roles of microglia on neurodevelopment and cognition in young offspring rats with prenatal sleep deprivation. Pregnant Wistar rats received 72 h sleep deprivation in the last trimester of gestation, and their prepuberty male offspring were given the intraperitoneal injection with or without minocycline. The results showed the number of Iba1(+) microglia increased, that of hippocampal neurogenesis decreased, and the hippocampus-dependent spatial learning and memory were impaired in MSD offspring. The classical microglial activation markers (M1 phenotype) IL-1ß, IL-6, TNF-α, CD68 and iNOS were increased, while the alternative microglial activation markers (M2 phenotype) Arg1, Ym1, IL-4, IL-10 and CD206 were reduced in hippocampus of MSD offspring. After minocycline administration, the MSD offspring showed improvement in MWM behaviors and increase in BrdU(+)/DCX(+) cells. Minocycline reduced Iba1(+) cells, suppressed the production of pro-inflammatory molecules, and reversed the reduction of M2 microglial markers in the MSD prepuberty offspring. These results indicate that dysregulation in microglial pro- and anti-inflammatory activation is involved in MSD-induced inhibition of neurogenesis and impairment of spatial learning and memory.