Chronic social defeat stress induces anxiety-like behaviors via downregulation of serotonin transporter in the prefrontal serotonergic system in mice.

The serotonergic (5-HTergic) system is closely involved in the pathophysiology of mood and anxiety disorders and the responsibility of this system may differ for each symptom. In this study, we examined the relationship between the dysfunction of the 5-HTergic system and abnormal behaviors in the social defeat stress model, an animal model of mood and anxiety disorders and in mice with knockdown of Slc6a4, the gene encoding SERT. Monoamine content, serotonin (5-HT) release, 5-HT uptake, 5-HT transporter (SERT) protein levels, and behaviors were investigated in mice subjected to chronic social defeat stress and in mice with knockdown of Slc6a4, in 5-HTergic neurons projecting to the prefrontal cortex (PFC). Furthermore, DNA methylation of Slc6a4 was examined in mice subjected to chronic social defeat stress. Increased turnover, increased extracellular basal levels, decreased release and decreased uptake of 5-HT, and decreased SERT protein levels were observed in the PFC of the stressed mice. The decreased 5-HT uptake correlated with anxiety-like behavior characterized by decreased time spent in the open arms of the elevated plus maze. DNA methylation was increased in the CpG island of Slc6a4 in 5-HTergic neurons projecting to the PFC of the stressed mice. Similar to the stressed mice, mice with Slc6a4 knockdown in 5-HTergic neurons projecting to the PFC also showed decreased release and uptake of 5-HT in the PFC and increased anxiety-like behavior. Chronic stress may induce anxiety due to dysfunction in the prefrontal 5-HTergic system via decreased SERT expression in the PFC.

2'-Fucosyllactose Alleviates Early Weaning-Induced Anxiety-Like Behavior, Amygdala Hyperactivity, and Gut Microbiota Changes.

Early life stress has a significant impact on development of the central nervous system (CNS), with lasting rather than transient consequences; therefore, it is important to alleviate these effects. In recent years, functional communication between the CNS and gut microbiota through the so-called brain-gut-microbiota axis has been examined, and it is likely that prebiotics contribute to development of the CNS through the gut microbiota. In this study, we performed behavioral, neurohistological, and fecal microbiota analyses in early-weaned mice to examine the effects of 2'-fucosyllactose (2'-FL), a human milk oligosaccharide, on anxiety induced by early life stress. Mice weaned at 17 d old (17-d mice) showed anxiety-like behaviors, such as decreased time in the open arms in the elevated plus maze test, compared to mice weaned at 24 d old (24-d mice). The number of cells that were positive for the neuronal activity marker c-Fos in the amygdala was also higher in 17-d mice. The behavioral and neural abnormalities caused by early weaning were alleviated by post-weaning ingestion of 2'-FL. The composition of the fecal microbiota differed among control diet-fed 24-d and 17-d mice, and 2'-FL diet-fed 17-d mice. These findings indicate that human milk oligosaccharides 2'-FL alleviate early stress-induced anxiety, amygdala hyperactivity, and gut microbiota changes.

Methyl Donor Supplementation Prevents a Folate Deficiency-induced Depression-like State and Neuronal Immaturity of the Dentate Gyrus in Mice.

We have recently shown that folate deficiency induces depression-like behavior and neuronal immaturity in the dentate gyrus (DG) in mice. We also revealed that folate deficiency inhibits neuronal maturation, hypomethylates the promoter of certain neuronal genes and decreases intracellular levels of S-adenosylmethionine (SAM), a methyl donor, in cultured neural stem and progenitor cells. Based on these findings, we hypothesized that SAM reduction may be involved in a folate deficiency-induced depressive state and neural immaturity. In this study, we examined whether SAM supplementation prevents depression-like behavior and neural immaturity in low folate diet-fed mice. Intraperitoneal administration of SAM (50 mg/kg/day) for 14 days from 7 weeks old prevented increased immobility in low folate diet-fed mice. SAM supplementation also prevented an increase in the number of doublecortin (an immature neuron marker)-positive cells and a decrease in the number of NeuN (a mature neuron marker)/5-bromo-2'-deoxyuridine (a proliferation marker)-double positive cells in the DG of these mice. Furthermore, neurofunctional and neuromorphological abnormalities in the DG of low folate diet-fed mice, such as decreases in stress-induced expression of c-Fos (a neuronal activity marker), dendritic complexity and the number of mature spines, were improved by SAM supplementation. The disrupted expression of transcription factors involved in neuronal differentiation and maturation was also normalized by SAM supplementation. These results suggest that SAM reduction may be involved in a folate deficiency-induced depressive state.

Kihito prevents corticosterone-induced brain dysfunctions in mice.

Kihito (KIT; Gui Pi Tang) is a traditional herbal medicine that is used for treatment of neuropsychiatric disorders such as depression, anxiety, neurosis and insomnia in China and Japan. Recently, it has also been shown that KIT improves cognitive dysfunction in patients with Alzheimer's disease. In this study, to investigate the mechanisms underlying the effects of KIT on stress-induced brain dysfunctions such as a depressed state and memory impairment, we examined whether KIT prevents behavioral and neurophysiological abnormalities in mice treated chronically with corticosterone (CORT). CORT (40 mg/kg/day, s.c.) and KIT (1000 mg/kg/day, p.o.) were given to 7-week-old male ddY mice for 14 days. Twenty-four hours after the last treatment, depression-like behavior in the forced swim test, spatial memory in the Barnes maze test, cell survival and the number of new-born immature neurons, dendritic spine density and expression levels of mRNA for neurotrophic factors were analyzed. Depression-like behavior and spatial memory impairment were observed in CORT-treated mice without KIT treatment. Hippocampal cell survival, the number of hippocampal new-born immature neurons, hippocampal and accumbal dendritic spine density and mRNA levels for neurotrophic factors such as glial cell line-derived neurotrophic factor (GDNF) were decreased in CORT-treated mice without KIT treatment. KIT prevented CORT-induced depression-like behavior, spatial memory impairment, and decreases in hippocampal cell survival, the number of hippocampal new-born immature neurons, accumbal dendritic spine density and GDNF mRNA. KIT may ameliorate stress-induced brain dysfunctions via prevention of adverse effects of CORT on cell survival, new-born immature neurons, spine density and neurotrophic factors.

Low folate induces abnormal neuronal maturation and DNA hypomethylation of neuronal differentiation-related genes in cultured mouse neural stem and progenitor cells.

Folate deficiency in a fetus is well known to cause neurodevelopment defects and development disorders. A low level of folate is also thought to be a risk for depression in adults. We have previously shown that post-weaning low folate induces neuronal immaturity in the dentate gyrus in mice, which suggests that low folate causes neuropsychological disorders via inhibition of neuronal maturation. In this study, we examined the effects of low folate on expression and epigenetic modification of genes involved in neuronal differentiation and maturation in primary mouse neural stem/progenitor cells (NSPCs) in vitro. An increase in Nestin (NSPC marker)-positive cells was observed in cells differentiated in a low folate medium for 3 days. An increase in ßIII-tubulin (Tuj1: immature neuron marker)-positive cells and a decrease in microtubule-associated protein 2 (MAP2: mature neuron marker)-positive cells were observed in cells differentiated in a low folate medium for 7 days. In these cells, mRNA levels for genes involved in neuronal differentiation and maturation were altered. Hypomethylation of DNA, but not of histone proteins, was also observed at some promoters of these neuronal genes. The level of S-adenosylmethionine (SAM), a methyl donor, was decreased in these cells. The abnormalities in neural maturation and changes in gene expression in culture under low folate conditions were partially normalized by addition of SAM (5 µM). Based on these results, decreased SAM may induce DNA hypomethylation at genes involved in neuronal differentiation and maturation under low folate conditions, and this hypomethylation may be associated with low folate-induced neuronal immaturity.

Ferulic acid alleviates abnormal behaviors in isolation-reared mice via 5-HT1A receptor partial agonist activity.

RATIONALE: Preclinical and clinical reports suggest that ferulic acid (FA), a plant-derived phenylpropanoid, is effective against mental health problems such as agitation, anxiety, and irritability in humans, without causing adverse side effects. However, the mechanism of action is unknown. OBJECTIVE: The aim of the study is to investigate the mechanism underlying the ameliorative effects of FA on mental health problems such as agitation, anxiety, and irritability, using in vivo behavioral analysis, in vitro pharmacological analysis, and in silico binding analysis. METHODS: The effects of FA (10 mg/kg, 50 mg/kg, and 250 mg/kg) on hyperactivity and aggressive behaviors of isolation-reared mice were examined. The effects of FA (50 mg/kg and 250 mg/kg) on extracellular levels of monoamines such as serotonin (5-HT), dopamine, and noradrenaline were analyzed by in vivo microdialysis. The effects of FA (10-13-10-6 M) on 5-HT1A and 5-HT2A receptors were analyzed using a luciferase reporter gene assay. Binding of FA to the mouse 5-HT1A receptor was evaluated by in silico analysis. RESULTS: The behavioral analysis showed that administration of FA (50 mg/kg) 1 h before experiments significantly alleviated hyperactivity and aggressive behaviors in isolation-reared mice. These alleviative effects were abolished by pretreatment with the 5-HT1A receptor antagonist WAY-100635 (1 mg/kg). In vivo microdialysis analysis showed that FA (50 mg/kg) did not change extracellular monoamine levels in the prefrontal cortex of mice. The luciferase reporter gene assay indicated that FA activated 5-HT1A receptors, but not 5-HT2A receptors, in a dose-dependent manner. The maximal response of 5-HT1A receptors to FA was weaker than that to 8-hydroxy-2-dipropylaminotetralin (8-OH-DPAT), a 5-HT1A receptor full agonist. In silico binding analysis showed that FA binds to the orthosteric site of 5-HT1A receptors. CONCLUSION: Taken together, these results suggest that FA ameliorates agitation-, anxiety-, and irritability-like behaviors such as hyperactivity and aggressive behaviors in isolation-reared mice via 5-HT1A receptor partial agonist activity. These findings support the efficacy of FA on mental health problems that have been suggested in preclinical and clinical practice.

Post-weaning folate deficiency induces a depression-like state via neuronal immaturity of the dentate gyrus in mice.

Folate deficiency has been suggested as a risk factor for depression in preclinical and clinical studies. Several hypotheses of mechanisms underlying folate deficiency-induced depressive symptoms have been proposed, but the detailed mechanisms are still unclear. In this study, we assessed whether post-weaning folate deficiency affect neurological and psychological function. The low folate diet-fed mice showed depression-like behavior in the forced swim test. In contrast, spontaneous locomotor activity, social behavior, coordinated motor skills, anxiety-like behavior and spatial memory did not differ between control and low folate diet-fed mice. In the dentate gyrus (DG) of the hippocampus, decreased number of newborn mature neurons and increased number of immature neurons were observed in low folate diet-fed mice. Staining with Golgi-Cox method revealed that dendritic complexity, spine density and the number of mature spines of neurons were markedly reduced in the DG of low folate diet-fed mice. Stress response of neurons indicated as c-Fos expression was also reduced in the DG of low folate diet-fed mice. These results suggest that reduction in the degree of maturation of newborn hippocampal neurons underlies folate deficiency-induced depressive symptoms.

Post-weaning social isolation of mice: A putative animal model of developmental disorders.

Post-weaning social isolation of laboratory animals is known to induce many behavioural and neurochemical abnormalities, which resemble neuropsychiatric disorders such as depression and anxiety. Therefore, they can help provide a suitable animal model to investigate the pathophysiology of neuropsychiatric symptoms and explore potential drugs for the treatment of neuropsychiatric diseases. Our recent studies have demonstrated that post-weaning social isolation of mice for no less than one week causes behaviour changes such as reduced attention, impaired social affiliation behaviour, and impaired conditional fear memories. Our neuropharmacological analyses have revealed that these behavioural features are modulated by different neuronal mechanisms, suggesting that post-weaning social isolation of mice can help provide an animal model with comorbid symptoms of patients with developmental disorders, including attention-deficit hyperactivity disorder, autism spectrum disorder, and specific learning disability. In this review, we discuss the neuropharmacological features of developmental disorder-like behaviour induced by post-weaning social isolation in mice to offer new insights into the pathophysiology of developmental disorders and possible therapeutic strategies.

The combination of maternal blood and amniotic fluid biomarkers improves the predictive accuracy of histologic chorioamnionitis.

INTRODUCTION: This study was performed to determine whether the combination of maternal blood and amniotic fluid biomarkers can improve the predictive accuracy of histologic chorioamnionitis (HC). METHODS: This retrospective study included 80 singleton pregnant women who were suspected to have intrauterine infection and underwent measurement of two maternal blood biomarkers [maternal white blood cell count (mWBC) and maternal C-reactive protein level (mCRP)] and three amniotic fluid biomarkers [amniotic white blood cell count (aCell), amniotic glucose level (aGlucose), and amniotic lactate dehydrogenase level (aLDH)]. We divided the patients into two groups based on the presence or absence of HC and assessed the predictors of HC using logistic regression models: Model 1, combination of mWBC and mCRP; Model 2, combination of Model 1 and aGlucose; and Model 3, combination of Model 2, aCell, and aLDH. RESULTS: The multivariable analysis showed that aCell was the only significant predictor of HC [odds ratio, 1.24; 95% confidence interval (CI), 1.06-1.68] independent of mWBC, mCRP, aGlucose, and aLDH. The c-statistics were higher in Model 3 (0.803; 95% CI, 0.701-0.905) than Model 1 (0.634; 95% CI, 0.511-0.758) and Model 2 (0.785; 95% CI, 0.684-0.887). DISCUSSION: We found that the combination of maternal blood and amniotic fluid biomarkers can improve the predictive accuracy of HC. Therefore, our data provide relevant information to support counseling with regard to improving the predictive accuracy of HC in patients with suspected intrauterine infection.

Single-Needle Intensive Granulocyte and Monocyte Adsorptive Apheresis Is Suitable for Elderly Patients With Active Ulcerative Colitis Taking no Corticosteroids or Biologics.

Twice-weekly intensive granulocyte/monocyte adsorptive apheresis is effective and safe for ulcerative colitis, but maintaining two blood access routes is problematic. We previously reported that intensive granulocyte/monocyte adsorptive apheresis using a single needle in ulcerative colitis is effective and safe. We hypothesized that the efficacy and safety of single-needle intensive granulocyte/monocyte adsorptive apheresis for ulcerative colitis would especially benefit the elderly. We enrolled 17 elderly ulcerative colitis patients to receive single-needle intensive granulocyte/monocyte adsorptive apheresis, 27 elderly ulcerative colitis patients to receive double-needle intensive granulocyte/monocyte adsorptive apheresis, and 52 nonelderly ulcerative colitis patients to receive single-needle intensive granulocyte/monocyte adsorptive apheresis. Remission and mucosal healing rates after treatment did not differ significantly between elderly ulcerative colitis patients receiving single-needle apheresis and the other two groups. In addition, no serious adverse effects, including blood clots, were observed in single-needle intensive granulocyte/monocyte adsorptive apheresis patients. Single-needle intensive granulocyte/monocyte adsorptive apheresis might be a novel alternative therapeutic option for elderly ulcerative colitis patients before considering corticosteroids.

Kami-shoyo-san ameliorates sociability deficits in ovariectomized mice, a putative female model of autism spectrum disorder, via facilitating dopamine D1 and GABAA receptor functions.

ETHNOPHARMACOLOGICAL RELEVANCE: Kami-shoyo-san (KSS) is a Kampo formula used clinically for menopause-related symptoms in Japan. However, the effect of KSS on autism spectrum disorder (ASD), a developmental disorder with a higher prevalence in males than in females, has not been reported yet. AIM OF THE STUDY: It is accepted generally that dysfunction in the GABAergic system is associated with pathogenesis of ASD. In our previous study, a decrease in brain allopregnanolone (ALLO), a positive allosteric GABAA receptor modulator, induced ASD-like symptoms such as impaired sociability-related performance and increased repetitive self-grooming behavior in male mice, and that KSS ameliorated these behavioral abnormalities via GABAA receptor- and dopamine D1 receptor-mediated mechanisms. In this study, to better understand a gender difference in the prevalence of ASD, we examined whether dissection of ovary (OVX), a major organ secreting progesterone in females, causes ASD-like behaviors in a manner dependent on brain ALLO levels, and if so, how KSS affects the behaviors. MATERIALS AND METHODS: Six-week-old ICR female mice received ovariectomy, and KSS (74 mg/kg and 222 mg/kg, p.o.) were treated before 1 h starting each behavioral test. The sociability, social anxiety-like behavior, and self-grooming behavior were analyzed by the resident-intruder test, mirror chamber test, and open field test, respectively. After finishing the behavioral experiment, the ALLO content in the brain was measured by ELISA. Furthermore, we examined the effects of OVX on the neuro-signaling pathways in the prefrontal cortex and striatum by Western blotting. RESULTS: The results revealed that OVX induced sociability deficits and social anxiety-related behaviors, but not repetitive self-grooming behavior, and that these behavioral changes were accompanied not only by a decrease of brain ALLO levels, but also by impairment of CREB- and CaMKIIα-mediated neuro-signaling in the prefrontal cortex. Moreover, the administration of KSS had no effect on the brain ALLO level, but significantly ameliorated the OVX-induced behavioral and neurochemical changes via facilitation of GABAA receptor and dopamine D1 receptor-mediated neurotransmission. CONCLUSIONS: These findings suggest that a decrease in gonadal hormone-derived ALLO plays a major role in ASD-like behaviors in female mice and that KSS is beneficial for the treatment of ASD in females.

Kami-shoyo-san improves ASD-like behaviors caused by decreasing allopregnanolone biosynthesis in an SKF mouse model of autism.

Dysfunctions in the GABAergic system are associated with the pathogenesis of autism spectrum disorder (ASD). However, the mechanisms by which GABAergic system dysfunctions induce the pathophysiology of ASD remain unclear. We previously demonstrated that a selective type I 5α-reductase inhibitor SKF105111 (SKF) induced ASD-like behaviors, such as impaired sociability-related performance and repetitive grooming behaviors, in male mice. Moreover, the effects of SKF were caused by a decrease in the endogenous levels of allopregnanolone (ALLO), a positive allosteric modulator of the GABAA receptor. In this study, we used SKF-treated male mice as a putative animal model of ASD and examined the effects of Kami-shoyo-san (KSS) as an experimental therapeutic strategy for ASD. KSS is a traditional Kampo formula consisting of 10 different crude drugs and has been used for the treatment of neuropsychiatric symptoms. KSS dose-dependently attenuated sociability deficits and suppressed an increase in grooming behaviors in SKF-treated mice without affecting ALLO content in the prefrontal cortex. The systemic administration of the dopamine D1 receptor antagonist SCH23390 reversed the ameliorative effects of KSS. On the other hand, the dopamine D2 receptor antagonist sulpiride and GABAA receptor antagonist bicuculline only attenuated the ameliorative effect of KSS on repetitive self-grooming behaviors. The present results indicate that KSS improves SKF-induced ASD-like behaviors by facilitating dopamine receptor-mediated mechanisms and partly by neurosteroid-independent GABAA receptor-mediated neurotransmission. Therefore, KSS is a potential candidate for the treatment of ASD.

Kamiuntanto increases prefrontal extracellular serotonin levels and ameliorates depression-like behaviors in mice.

Kamiuntanto (KUT; Jia Wei Wen Dan Tang in Pinyin) is a traditional Japanese Kampo medicine that is used to treat psychological dysfunction. However, the mechanisms of action of KUT are not understood. To investigate the mechanisms underlying the ameliorative properties of KUT, the effects of KUT on abnormal behaviors of isolation-reared mice and on the prefrontal monoaminergic system were examined. KUT (1000 mg/kg) reversed encounter-induced hyperactivity and increased immobility in the forced swim test in isolation-reared mice, as also found for an antidepressant, fluoxetine (30 mg/kg). In vivo microdialysis showed that KUT (1000 mg/kg) transiently increased the level of extracellular serotonin (5-HT) in the prefrontal cortex. In contrast, an incomplete KUT formula excluding Bambusae Caulis (BC), a component herb of KUT, did not reverse abnormal behaviors of isolation-reared mice or increase prefrontal extracellular 5-HT. Furthermore, the antidepressant-like effect of KUT in the forced swim test was prevented by pretreatment with GR127935, a 5-HT1B antagonist. These findings suggest that KUT may ameliorate depressive symptoms via 5-HTergic systems, and that BC plays an important role in the antidepressant-like effects of KUT.

Association of Serum HB-EGF Value and Response to Chemotherapy in Patients with Recurrent Ovarian Cancer.

BACKGROUND/AIM: Many anticancer agents including molecularly-targeted drugs have been developed for ovarian cancer. However, the prognosis of recurrent ovarian cancer remains extremely poor. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is reported as a rational target for ovarian cancer therapy. Moreover, serum HB-EGF expression is recognized as a biomarker in patients with primary ovarian cancer. MATERIALS AND METHODS: We analysed serum samples with recurrent ovarian cancer at the Fukuoka University Hospital from April 2009 to March 2014. To assess the clinical significance of serum HB-EGF in recurrent ovarian cancer, the association between serum HB-EGF levels and prognosis in patients with recurrent ovarian cancer was examined using ELISA. RESULTS: Patients with high serum HB-EGF expression showed a significantly poor response to second-line chemotherapeutic agents compared with patients with low HB-EGF levels. CONCLUSION: HB-EGF expression in serum may be a potential therapeutic indicator for novel HB-EGF-targeted therapy in recurrent ovarian cancer.

Sansoninto, a traditional herbal medicine, ameliorates behavioral abnormalities and down-regulation of early growth response-1 expression in mice exposed to social isolation stress.

Social isolation (SI) mice exhibit behavioral abnormalities such as impairments of sociability- and attention-like behaviors, offering an animal model of neurodevelopmental disorders such as attention-deficit/hyperactivity disorder (ADHD). This study aimed to identify the effects of Sansoninto (SST; suan zǎo rén tang) on the psychiatric symptoms related to ADHD using SI mice. Four-week-old mice were socially isolated during the experimental period, and SST administration (800 or 2400 mg/kg, p.o.) was started at 2 weeks after starting SI. SST ameliorated SI-induced impairments of sociability- and attention-like behaviors in a dose-dependent manner, and tended to ameliorate contextual- and auditory-dependent fear memory deficit. Moreover, the expression level of Egr-1 was down-regulated by SI stress, and was restored by a high dose of SST. These findings suggest that SST is useful for improvement of psychiatric disorders such as ADHD.

Microbiome profile of the amniotic fluid as a predictive biomarker of perinatal outcome.

Chorioamnionitis (CAM), an inflammation of the foetal membranes due to infection, is associated with preterm birth and poor perinatal prognosis. The present study aimed to determine whether CAM can be diagnosed prior to delivery based on the bacterial composition of the amniotic fluid (AF). AF samples from 79 patients were classified according to placental inflammation: Stage III (n = 32), CAM; Stage II (n = 27), chorionitis; Stage 0-I (n = 20), sub-chorionitis or no neutrophil infiltration; and normal AF in early pregnancy (n = 18). Absolute quantification and sequencing of 16S rDNA showed that in Stage III, the 16S rDNA copy number was significantly higher and the α-diversity index lower than those in the other groups. In principal coordinate analysis, Stage III formed a separate cluster from Stage 0-I, normal AF, and blank. Forty samples were classified as positive for microbiomic CAM (miCAM) defined by the presence of 11 bacterial species that were found to be significantly associated with CAM and some parameters of perinatal prognosis. The diagnostic accuracy for CAM according to miCAM was: sensitivity, approximately 94%, and specificity, 79-87%. Our findings indicate the possibility of predicting CAM prior to delivery based on the AF microbiome profile.

Serum Heparin-binding Epidermal Growth Factor-like Growth Factor (HB-EGF) as a Biomarker for Primary Ovarian Cancer.

Ovarian cancer is the most lethal malignancy among gynaecological cancers. Although many anticancer agents have been developed for the treatment of ovarian cancer, it continues to have an extremely poor prognosis. Heparin-binding epidermal growth factor-like grown factor (HB-EGF) has been reported to be a rational therapeutic target for ovarian cancer. Here, we evaluated the clinical significance of serum HB-EGF by examining the association between prognosis and serum HB-EGF levels in patients with primary ovarian cancer. We found that high serum HB-EGF concentrations were significantly associated with poor prognosis in a combined cohort of patients with all stages of ovarian cancer, as well as in a subset of patients with advanced disease. In addition, serum HB-EGF levels increased as the cancer advanced. These data suggest that serum HB-EGF may be a target for the design of novel therapies for ovarian cancer.

Decrease in endogenous brain allopregnanolone induces autism spectrum disorder (ASD)-like behavior in mice: A novel animal model of ASD.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with core symptoms of social impairments and restrictive repetitive behaviors. Recent evidence has implicated a dysfunction in the GABAergic system in the pathophysiology of ASD. We investigated the role of endogenous allopregnanolone (ALLO), a neurosteroidal positive allosteric modulator of GABAA receptors, in the regulation of ASD-like behavior in male mice using SKF105111 (SKF), an inhibitor of type I and type II 5α-reductase, a rate-limiting enzyme of ALLO biosynthesis. SKF impaired sociability-related performance, as analyzed by three different tests; i.e., the 3-chamber test and social interaction in the open field and resident-intruder tests, without affecting olfactory function elucidated by the buried food test. SKF also induced repetitive grooming behavior without affecting anxiety-like behavior. SKF had no effect on short-term spatial working memory or long-term fear memory, but enhanced latent learning ability in male mice. SKF-induced ASD-like behavior in male mice was abolished by the systemic administration of ALLO (1mg/kg, i.p.) and methylphenidate (MPH: 2.5mg/kg, i.p.), a dopamine transporter inhibitor. The effects of SKF on brain ALLO contents in male mice were reversed by ALLO, but not MPH. On the other hand, SKF failed to induce ASD-like behavior or a decline in brain ALLO contents in female mice. These results suggest that ALLO regulates episodes of ASD-like behavior by positively modulating the function of GABAA receptors linked to the dopaminergic system. Moreover, a sex-dependently induced decrease in brain ALLO contents may provide an animal model to study the main features of ASD.

Daily administration of yokukansan and keishito prevents social isolation-induced behavioral abnormalities and down-regulation of phosphorylation of neuroplasticity-related signaling molecules in mice.

BACKGROUND: Our previous studies demonstrated that post-weaning social isolation (ISO) in mice induces behavior abnormalities such as deficits of sociability- and attention-like behaviors. These deficits can be attenuated by methylphenidate (MPH), a drug used for attention deficit hyperactivity disorder (ADHD), suggesting that ISO mice offer a potential animal model of comorbid developmental disorder with ADHD and autism spectrum disorder symptoms. This study investigated the effects of Kampo formulae, yokukansan (YKS) and keishito (KST), on the neuropsychiatric symptoms of ISO mice to clarify the therapeutic or preventive/delaying potential of these formulae for the treatment of neurodevelopmental disorders. METHODS: Three-to-4-week old male ICR mice were socially isolated during an experimental period and YKS and KST (1523.6 and 2031.8 mg/kg, p.o.) was administered starting from week 2 and week 0 after starting ISO for the analysis of their therapeutic and preventive/delaying potentials, respectively. Sociability, attention-related behavior and fear memory were elucidated by a 3 chamber test, a water-finding test and fear conditioning test, respectively. Moreover, the phosphorylation of neuroplasticity-related signaling molecules in mice hippocampus was analyzed using western blotting. RESULTS: In a therapeutic procedure, YKS ameliorated ISO-induced impairments of attention-like behavior and context-dependent fear memory, but not of sociability, whereas KST had no beneficial effects in ISO mice. In experiments to analyze the preventive/delaying potentials of these treatments, both YKS and KST improved sociability, attention, and context-dependent fear memory deficits. The improvement of sociability in mice by YKS and KST was not inhibited by a dopamine D1 receptor antagonist, suggesting that YKS and KST improved the ISO-induced sociability deficit by other mechanisms besides activation of the dopaminergic system. On the other hand, the beneficial effects of YKS and KST on attention-like behavior were inhibited by a muscarinic antagonist, suggesting that YKS and KST ameliorated ISO-induced attention-like behavior through a cholinergic mechanism. Moreover, the phosphorylated forms of CaMKII and CREB were down-regulated by ISO stress and restored by YKS and KST administration. CONCLUSIONS: These findings suggest that YKS and KST may be useful for the improvement of neurodevelopmental disorders.

Gomisin N ameliorates lipopolysaccharide-induced depressive-like behaviors by attenuating inflammation in the hypothalamic paraventricular nucleus and central nucleus of the amygdala in mice.

Emotional impairments such as depressive symptoms often develop in patients with sustained and systemic immune activation. The objective of this study is to investigate the effect of gomisin N, a dibenzocyclooctadiene lignan isolated from the dried fruits of Schisandra chinensis (Turcz.) Baill., which exhibited inhibitory effects of the bacterial endotoxin lipopolysaccharide (LPS)-induced NO production in a screening assay, on inflammation-induced depressive symptoms. We examined the effects of gomisin N on inflammation induced by LPS in murine microglial BV-2 cells and on LPS-induced behavioral changes in mice. Gomisin N inhibited LPS-induced expression of mRNAs for inflammation-related genes (inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α) in BV-2 cells. Administration of gomisin N attenuated LPS-induced expression of mRNAs for inflammation-related genes, increases in the number of c-Fos immunopositive cells in the hypothalamus and amygdala, depressive-like behavior in the forced swim test and exploratory behavior deficits 24 h after LPS administration in mice. These results suggest that gomisin N might ameliorate LPS-induced depressive-like behaviors through inhibition of inflammatory responses and neural activation in the hypothalamus and amygdala.