Hypnotic activities of Zao Ren An Shen capsule, a traditional Chinese medicine, in an anxiety-like mouse model.

PURPOSE: Zao Ren An Shen capsule (ZRASC) which is composed of three kinds of traditional Chinese herbs is a popular Chinese medicine for the treatment of insomnia. This study investigated the hypnotic effect of ZRASC in an anxiety-like mouse model. METHODS: We determined the role of ZRASC in anxiety and co-morbid insomnia using electroencephalogram and electromyogram recordings. Anxiety-like behaviors were tested by using the open-field, light/dark box, or elevated plus-maze in mice. Immunohistochemical techniques were employed to reveal the mechanism by which ZRASC regulated anxiety and insomnia. RESULTS: ZRASC at 680 mg/kg prolonged the time spent in the central area, open arms area, and light box by 1.9, 2.3, and 1.7-fold respectively, compared with the vehicle control group in immobilization stress (IMS) mice. ZRASC at 680 mg/kg given at 08:00 h increased the amount of non-rapid eye movement sleep by 1.4-fold in a 2-h period after dosing in IMS mice. However, it did not alter the sleep-wake behaviors in normal mice. Immunohistochemistry showed that IMS increased c-Fos expression in the neurons of the stria terminalis and tuberomammillary nucleus by 1.8 and 1.6-fold, respectively. In addition, ZRASC (680 mg/kg) reversed the IMS-induced c-Fos expression. CONCLUSIONS: Our results suggest that ZRASC is an effective therapeutic strategy for both anxiety disorder and sleep disturbances in an anxiety-like mouse model.

Activation of Parabrachial Nucleus Glutamatergic Neurons Accelerates Reanimation from Sevoflurane Anesthesia in Mice.

BACKGROUND: The parabrachial nucleus (PBN), which is a brainstem region containing glutamatergic neurons, is a key arousal nucleus. Injuries to the area often prevent patient reanimation. Some studies suggest that brain regions that control arousal and reanimation are a key part of the anesthesia recovery. Therefore, we hypothesize that the PBN may be involved in regulating emergence from anesthesia. METHODS: We investigated the effects of specific activation or inhibition of PBN glutamatergic neurons on sevoflurane general anesthesia using the chemogenetic "designer receptors exclusively activated by designer drugs" approach. Optogenetic methods combined with polysomnographic recordings were used to explore the effects of transient activation of PBN glutamatergic neuron on sevoflurane anesthesia. Immunohistochemical techniques are employed to reveal the mechanism by which PBN regulated sevoflurane anesthesia. RESULTS: Chemogenetic activation of PBN glutamatergic neurons by intraperitoneal injections of clozapine-N-oxide decreased emergence time (mean ± SD, control vs. clozapine-N-oxide, 55 ± 24 vs. 15 ± 9 s, P = 0.0002) caused by sevoflurane inhalation and prolonged induction time (70 ± 15 vs. 109 ± 38 s, n = 9, P = 0.012) as well as the ED50 of sevoflurane (1.48 vs. 1.60%, P = 0.0002), which was characterized by a rightward shift of the loss of righting reflex cumulative curve. In contrast, chemogenetic inhibition of PBN glutamatergic neurons slightly increased emergence time (56 ± 26 vs. 87 ± 26 s, n = 8, P = 0.034). Moreover, instantaneous activation of PBN glutamatergic neurons expressing channelrhodopsin-2 during steady-state general anesthesia with sevoflurane produced electroencephalogram evidence of cortical arousal. Immunohistochemical experiments showed that activation of PBN induced excitation of cortical and subcortical arousal nuclei during sevoflurane anesthesia. CONCLUSIONS: Activation of PBN glutamatergic neurons is helpful to accelerate the transition from general anesthesia to an arousal state, which may provide a new strategy in shortening the recovery time after sevoflurane anesthesia.

Aesthetic principles access thyroidectomy produces the best cosmetic outcomes as assessed using the patient and observer scar assessment scale.

BACKGROUND: Thyroid carcinoma (TC) is more likely to occur in young women. The aim of this study was to compare the aesthetic effect of different thyroidectomies. METHODS: One hundred twenty female patients who underwent thyroidectomy were evenly distributed into three groups: conventional access (CA), aesthetic principles access (APA) and minimally invasive access (MIA). The Patient and Observer Scar Assessment Scale (POSAS) was used as the assessment tool for the linear scar. RESULTS: The patients in the MIA group showed significantly less intraoperative blood loss, less drainage, a shorter scar length and a shorter duration of drainage than those in the CA group and the APA group. However, the operation time of 129.0 min in the MIA group was significantly longer than the 79.6 min in the CA group and the 77.0 min in the APA group. The best aesthetic score, as assessed by the Observer Scar Assessment Scale (OSAS), was obtained in the APA group. The Patient Scar Assessment Scale (PSAS) scores were significantly lower in the APA group and CA group than in the MIA group. Significantly lower objective scar ratings were found in the APA group than in the other two groups. CONCLUSION: These results show that APA produced the best surgical outcomes in TC patients, indicating that conventional thyroidectomy can produce an ideal aesthetic result using the principles of aesthetic surgery. Thyroid surgery need not be performed through excessively short incisions for the sake of patient satisfaction with the scar's appearance. TRIAL REGISTRATION: This clinical trial was retrospectively registered on ClinicalTrials.gov PRS on August 1st,2017 ( NCT03239769 ).

Helicid alleviates pain and sleep disturbances in a neuropathic pain-like model in mice.

Natural helicid (4-formylphenyl-O-ß-d-allopyranoside), a main active constituent from seeds of the Chinese herb Helicia nilagirica, has been reported to exert a sedative, analgesic and hypnotic effect, and is used clinically to treat neurasthenic syndrome, vascular headaches and trigeminal neuralgia. In the current study, mechanical allodynia tests, electroencephalograms, electromyogram recordings and c-Fos expression in neuropathic pain-like model mice of partial sciatic nerve ligation were used to investigate the effect of helicid on neuropathic pain and co-morbid insomnia. Our results showed that helicid at a dose of 100, 200 or 400 mg kg-1 could increase the mechanical threshold by 2.5-, 2.8- and 3.1-fold for 3 h after administration, respectively. Helicid at 200 and 400 mg kg-1 given at 07:00 hours increased the amount of non-rapid eye movement sleep in a 3-h period by 1.27- and 1.35-fold in partial sciatic nerve ligated mice. However, helicid (400 mg kg-1 ) given at 21:00 hours did not change the sleep pattern in normal mice. Immunohistochemical study showed that helicid (400 mg kg-1 ) administration could reverse the increase of c-Fos expression in the neurons of the rostral anterior cingulate cortex and tuberomammillary nucleus, and the decrease of c-Fos expression in the ventrolateral preoptic area caused by partial sciatic nerve ligation. These results indicate that helicid is an effective agent for both neuropathic pain and sleep disturbances in partial sciatic nerve ligated mice.

Gelsemine alleviates both neuropathic pain and sleep disturbance in partial sciatic nerve ligation mice.

AIM: Gelsemine, an alkaloid from the Chinese herb Gelsemium elegans (Gardn & Champ) Benth., is effective in mitigating chronic pain in rats. In the present study we investigated whether the alkaloid improved sleep disturbance, the most common comorbid symptoms of chronic pain, in a mouse model of neuropathic pain. METHODS: Mice were subjected to partial sciatic nerve ligation (PSNL). After the mice were injected with gelsemine or pregabalin (the positive control) intraperitoneally, mechanical allodynia and thermal hyperalgesia were assessed, and electroencephalogram (EEG)/electromyogram (EMG) recording was performed. Motor performance of the mice was assessed using rota-rod test. c-Fos expression in the brain was analyzed with immunohistochemical staining. RESULTS: In PSNL mice, gelsemine (2 and 4 mg/kg) increased the mechanical threshold for 4 h and prolonged the thermal latencies for 3 h. Furthermore, gelsemine (4 mg/kg, administered at 6:30 AM) increased non-rapid eye movement (non-REM, NREM) sleep, decreased wakefulness, but did not affect REM sleep during the first 3 h in PSNL mice. Sleep architecture analysis showed that gelsemine decreased the mean duration of wakefulness and increased the total number of episodes of NREM sleep during the first 3 h after the dosing. Gelsemine (4 mg/kg) did not impair motor coordination in PSNL mice. Immunohistochemical study showed that PSNL increased c-Fos expression in the neurons of the anterior cingulate cortex, and gelsemine (4 mg/kg) decreased c-Fos expression by 58%. Gelsemine (4 mg/kg, administered at either 6:30 AM or 8:30 PM) did not produce hypnotic effect in normal mice. Pregabalin produced similar antinociceptive and hypnotic effects, but impaired motor coordination in PSNL mice. CONCLUSION: Gelsemine is an effective agent for treatment of both neuropathic pain and sleep disturbance in PSNL mice; anterior cingulate cortex might play a role in the hypnotic effects of gelsemine.

A new aurone glycoside from Veratrum dahuricum (Turcz.) Loes. f.

To study the chemical constituents of Veratrum dahuricum (Turcz.) Loes. f., a new aurone glycoside named as (Z)-7, 4'-dimethoxy-6-hydroxyl-aurone-4-O-ß-glucopyranoside was isolated from the 95% ethanol extracts of the rhizomes and roots of Veratrum dahuricum (Turcz.) Loes. f. by repeated column chromatography on silica gel and recrystallization. Its structure was established by extensive spectroscopic analyses, and its cytotoxicities against HepG-2, MCF7 and A549 cell lines were measured in vitro.

Notch1 contributes to chemoresistance to gemcitabine and serves as an unfavorable prognostic indicator in pancreatic cancer.

BACKGROUND: Pancreatic cancer (PC) carries frequent chemoresistance and extremely dismal prognosis. The underlying mechanisms remain to be further elucidated. We here report the role of Notch1 in gemcitabine resistance and its prognostic significance in PC. METHODS: A small interfering RNA (siRNA) specifically targeting Notch1 was transiently transfected into three PC cell lines (AsPC-1, BxPC-3, and MIA PaCa-2), followed by examination of chemosensitivity to gemcitabine. On the other hand, Notch1 expression was evaluated immunohistochemically and correlated with clinicopathological and prognostic variables. RESULTS: Successful knockdown of Notch1 by specific siRNA induced increased chemosensitivity to gemcitabine in all three cell lines. Immunohistochemical staining revealed that Notch1 was highly expressed in PC tissues (54.8 %), in contrast to that in para-tumor tissues (16.4 %). In addition, Notch1 positivity was significantly correlated with early-term metastasis and shortened overall survival. Multivariate Cox regression identified Notch1 as an independent prognostic factor. CONCLUSIONS: Notch1 contributes to chemoresistance to gemcitabine, and serves as a significant indicator of unfavorable prognosis in PC.

[Small interfering RNA targeting STAT3 enhances antitumor activity of doxorubicin].

This study is to investigate the effect of small interfering RNA targeting STAT3 (STAT3-siRNA) enhancing antitumor activity of doxorubicin. RT-PCR and Western blotting were used to test the expression of STAT3 mRNA and protein in the HepG2, HeLa and K562/DOX cells and the effect of STAT3-siRNA on the expression of STAT3 mRNA and protein. MTT and Trypan blue assay were performed to determine the inhibitory effect of STAT3-siRNA on HepG2, HeLa and K562/DOX cells and the effect of STAT3-siRNA enhancing antitumor activity of doxorubicin. The effects of STAT3-siRNA on intracellular accumulation of doxorubicin and cell apoptosis were performed by Arrary Scan V(TI)HCS600 High-Contents. The results showed that STAT3 gene, STAT3 and pSTAT3 protein were highly expressed in HepG2, HeLa and K562/DOX cells and STAT3-siRNA decreased the expression of STAT3 mRNA and protein. STAT3-siRNA inhibited the growth of HepG2, HeLa and K562/DOX cells. STAT3-siRNA in combination with doxorubicin decreased by 3.13, 5.22 and 1.74 fold of IC50 of HepG2, HeLa and K562/DOX cells compared with doxorubicin only. Intracellular accumulation of doxorubicin increased by 16.8%, 12.87% and 25.67% respectively in HepG2, HeLa and K562/DOX cells in the presence of STAT3-siRNA. An enhancement of doxorubicin-induced cell apoptosis was observed in HepG2, HeLa and K562/DOX cells treated with STAT3-siRNA. The results suggested that STAT3-siRNA could enhance the antitumor activity of doxorubicin on HepG2, HeLa and K562/DOX cells.

Endogenous cystathionine-gamma-lyase/hydrogen sulfide pathway regulates apoptosis of HepG2 cells.

This study is to investigate the role of endogenous CSE/H2S in regulating apoptosis of HepG2 cells. MTT and Trypan blue assay were performed to determine the effect of CSE inhibitor PAG and CSE siRNA on proliferation of HepG2. Production of H2S from HepG2 cells was assessed spectrophotometrically using N, N-dimethyl-p-phenylenediamine-dihydrochloride. Cells apoptosis was detected by means of double staining of Hoechst 33342 and PI with Array Scan V(TI)HCS600 High-Contents. Dihydroethidine (DHE) and 2', 7'-dichlorodihydrofluorescein diacetate (DCFH-DA) assay was used to determine intracellular superoxide anion and ROS level. Reduced glutathione (GSH) was determined by OxiSelect Total Glutathione Assay Kit. Recombinant plasmid pcDNA 3.1/myc-His(-)-CSE was constructed and transfected into 293T cells to rescue the ROS and GSH level to further investigate the effect of CSE/H2S on ROS and GSH. Western blotting was performed to test the effect of CSE siRNA on expression of activated caspase 3 and p-AKT and Nrf2 protein. The results showed that PAG and CSE siRNA could significantly decrease the production of H2S in HepG2 cells and inhibit the proliferation of HepG2 cells at a dose-dependent and time-dependent manner, respectively. PAG and CSE siRNA could promote the cell apoptosis of HepG2 cells. Moreover, PAG and CSE siRNA induced increased ROS generation and depletion of the critical antioxidant GSH and recombinant plasmid pcDNA 3.1/myc-His(-)-CSE rescued the level of ROS and GSH. Meanwhile, CSE siRNA increased the expression of activated caspase 3, but CSE siRNA did not affect the expression of p-AKT and Nrf2. These results suggested that the CSE/H2S pathway was involved in suppression of HepG2 cell growth and promoted apoptosis of HepG2 cells in an oxidative stress-dependent manner.

[Prosapogenin A inhibits cell growth of MCF7 via downregulating STAT3 and glycometabolism-related gene].

This study is to investigate the inhibitory effect and mechanism of prosapogenin A (PSA) on MCF7. MTT assay was performed to determine the inhibitory effect of PSA on MCF7 cells. PI/Hoechst 33342 double staining was used to detect cell apoptosis. RT-PCR was used to test the mRNA levels of STAT3, GLUT1, HK and PFKL. Western blotting was performed to determine the expression of STAT3 and pSTAT3 protein in MCF7 cells. The results showed that PSA could dose-dependently inhibit cell growth of MCF7 followed by IC50 of 9.65 micrmol x L(-1) and promote cell apoptosis of MCF7. Reduced mRNA levels of STAT3, HK and PFKL were observed in MCF7 cells treated with 5 micromol x L(-1) of PSA. PSA also decreased the level of pSTAT3 protein. STAT3 siRNA caused decrease of mRNA of GLUT1, HK and PFKL which indicated STAT3 could regulate the expressions of GLUT1, HK and PFKL. The results suggested that PSA could inhibit cell growth and promote cell apoptosis of MCF7 via inhibition of STAT3 and glycometabolism-related gene.

[Serum parathyroid hormone levels predict hospitalization in outpatients of heart failure: a preliminary study].

OBJECTIVE: To evaluate the predicative value of serum parathyroid hormone (PTH) levels in outpatients of heart failure (HF) for hospitalization. METHODS: A total of 102 consecutive HF outpatients were enrolled. The receiver operating characteristic (ROC) curves demonstrated the optimal cut-off points of PTH levels for hospitalization due to HF. And Logistic regression analysis model was employed to analyze the independent association between PTH and hospitalization for HF. RESULTS: The more advanced grade of New York Heart Association (NYHA), the higher serum level of PTH. The ROC curves showed PTH levels ≥ 56.05 ng/L were the optimal cut-off point for hospitalization for HF with a sensitivity of 90.0%, a specificity of 89.2% and the area under ROC curve of 0.92. After adjustment for predictors for hospitalization due to HF (gender, age, diabetes mellitus, hypertension, left ventricular ejection fraction, estimated glomerular filtration rate and brain natriuretic peptide), PTH levels were associated with hospitalization due to HF (OR = 1.282, 95%CI 1.026-1.362). CONCLUSION: The serum level of PTH in HF outpatients is an independent predicator for hospitalization due to HF.

[Chemical constituents from Psoralea corylifolia and their antioxidant alpha-glucosidase inhibitory and antimicrobial activities].

Twelve compounds were isolated from Psoralea corylifolia and their structures were identified as isopsoralen (1), psoralen (2), 8-methoxypsoralen (3), psoralidin (4), corylin (5), bavachin (6), daidzein (7), corylifolinin (8), bavachinin (9), neobavaisoflavone (10), daidzin (11) and astragalin (12). The results showed that psoralidin had the activity of scavenging DPPH free radicals activity (IC50 43.85 mg x L(-1)). Psoralidin (IC50 1.32 mg x L(-1))c, oryfolin (IC50 4.97 mg x L(-1)), daidzin (IC50 10.47 mg x S(-1)), daidzein (IC50 34.22 mg) x L(-1)) and astragalin (IC50 31.27 mg x L(-1)) had the activity of scavenging ABTS free radical. Psoralidin (IC50 40.74 mg x L(-1)), coryfolin (IC50 45.73 mg x L(-1)) and daidzein (IC50 49.44 mg x L(-1)) had alpha-glucosidase inhibitory activity. Corylifolinin and neobavaisoflavone had significantly effect of inhibiting SA, MRSA and ESBLs-SA (MIC 0. 781 3, 1.562, 5, 0.781 25 microg x disc(-1) and 6.25, 6.25, 6.25 microg x disc(-1).

Machine Learning-Based Integration of Metabolomics Characterisation Predicts Progression of Myopic Retinopathy in Children and Adolescents.

Myopic retinopathy is an important cause of irreversible vision loss and blindness. As metabolomics has recently been successfully applied in myopia research, this study sought to characterize the serum metabolic profile of myopic retinopathy in children and adolescents (4-18 years) and to develop a diagnostic model that combines clinical and metabolic features. We selected clinical and serum metabolic data from children and adolescents at different time points as the training set (n = 516) and the validation set (n = 60). All participants underwent an ophthalmologic examination. Untargeted metabolomics analysis of serum was performed. Three machine learning (ML) models were trained by combining metabolic features and conventional clinical factors that were screened for significance in discrimination. The better-performing model was validated in an independent point-in-time cohort and risk nomograms were developed. Retinopathy was present in 34.2% of participants (n = 185) in the training set, including 109 (28.61%) with mild to moderate myopia. A total of 27 metabolites showed significant variation between groups. After combining Lasso and random forest (RF), 12 modelled metabolites (mainly those involved in energy metabolism) were screened. Both the logistic regression and extreme Gradient Boosting (XGBoost) algorithms showed good discriminatory ability. In the time-validation cohort, logistic regression (AUC 0.842, 95% CI 0.724-0.96) and XGBoost (AUC 0.897, 95% CI 0.807-0.986) also showed good prediction accuracy and had well-fitted calibration curves. Three clinical characteristic coefficients remained significant in the multivariate joint model (p < 0.05), as did 8/12 metabolic characteristic coefficients. Myopic retinopathy may have abnormal energy metabolism. Machine learning models based on metabolic profiles and clinical data demonstrate good predictive performance and facilitate the development of individual interventions for myopia in children and adolescents.

Synergistic effects of cell-penetrating peptide Tat and fusogenic peptide HA2-enhanced cellular internalization and gene transduction of organosilica nanoparticles.

The nonviral gene delivery system is an attractive alternative to cancer therapy. A new kind of gelatin-silica nanoparticles (GSNPs) was developed through a two-step sol-gel procedure. To improve the transfection efficacy, GSNPs modified with different fusion peptides (Tat, HA2, R8, Tat/HA2, and Tat/R8) were prepared for particle size, zeta potential, cellular uptake, hemolysis activity at physiological pH (7.0) or acidic pH (5.0), and condensation of plasmid DNA. The results suggest that the sizes and zeta potentials of GS-peptide conjugates were 147 - 161 nm and 19 - 33 mV, respectively; GS-peptide conjugates exhibited low cytotoxicity; the plasmid DNA was readily entrapped at a GS-peptide/pDNA weight ratio of 50 - 200. The in vitro and in vivo studies demonstrated that the synergistic effects of cell-penetrating peptide Tat and fusogenic peptide HA2 could promote the efficient cellular internalization, endosome escape, and nucleus targeting, hence delivering the therapeutic nucleic acid efficiently.

Quercitrin restrains the growth and invasion of lung adenocarcinoma cells by regulating gap junction protein beta 2.

Lung adenocarcinoma (LUAD) is the most prevalent subtype of non-small cell lung cancer (NSCLC) with high lethality, and quercitrin exhibits anticancer characteristics. Here, we attempted to uncover the anticancer activity of quercitrin in LUAD. In this work, quercitrin prohibited the cell viability and clone-formation of LUAD cells in vitro. Meanwhile, quercitrin treatment reduced the aggressive phenotypes in LUAD cells. Further, Gap Junction Protein Beta 2 (GJB2) expression was aberrantly higher in LUAD when compared within control tissue. The higher expression of GJB2 is associated with an inferior overall survival for patients with LUAD. Finally, the reintroduction of GJB2 offset the inhibiting influence of quercitrin in LUAD cells. Altogether, these findings disclosed that quercitrin suppressed the growth and metastatic-related traits of LUAD cells partly via regulating GJB2 expression.

Nucleus accumbens neurons expressing dopamine D1 receptors modulate states of consciousness in sevoflurane anesthesia.

Although general anesthesia (GA) enables patients to undergo surgery without consciousness, the precise neural mechanisms underlying this phenomenon have yet to be identified. In addition to many studies over the past two decades implicating the thalamus, cortex, brainstem, and conventional sleep-wake circuits in GA-induced loss of consciousness (LOC), some recent studies have begun to highlight the importance of other brain areas as well. Here, we found that population activities of neurons expressing dopamine D1 receptor (D1R) in the nucleus accumbens (NAc), a critical interface between the basal ganglia and limbic system, began to decrease before sevoflurane-induced LOC and gradually returned after recovery of consciousness (ROC). Chemogenetic activation of NAcD1R neurons delayed induction of and accelerated emergence from sevoflurane GA, whereas chemogenetic inhibition of NAcD1R neurons exerted opposite effects. Moreover, transient activation of NAcD1R neurons induced significant cortical activation and behavioral emergence during continuous steady-state GA with sevoflurane or deep anesthesia state with constant and stable burst-suppression oscillations. Taken together, our findings uncover that NAcD1R neurons modulated states of consciousness associated with sevoflurane GA and may represent an area for targeting GA-induced changes in consciousness and ameliorating related adverse effects.

Serum parathyroid hormone levels in patients with chronic right heart failure.

Parathyroid hormone (PTH) is a novel cardiovascular biomarker which is particularly useful for detection and assessment of heart failure (HF). However, previous studies examining PTH in heart failure have primarily focused on left HF; thus, the relationship between PTH and right HF remains unclear. The aim of the present study was to evaluate the serum PTH levels in patients with chronic right HF. A total of 154 patients with chronic right HF were enrolled in the present study. A binary logistic regression analysis model was used to assess the independent predictive value of PTH levels in chronic right HF. Partial correlative analysis was used to demonstrate the relevance of PTH levels on the parameters of assessment of right heart function. A multiple linear regression analysis model was used to evaluate the independent factors of PTH levels in patients with right HF. The results showed that the serum PTH levels in the right HF group were significantly higher compared with the control group. After adjusting for predictors of right HF, serum PTH levels were associated with right HF with an odds ratio of 1.066 (95% confidence interval: 1.030-1.102, P<0.001. Serum PTH levels were independently correlated with plasma N-terminal pro-B-type natriuretic peptide levels, right ventricular end-diastolic diameter and severity of lower extremity edema (all P<0.05). Therefore, based on the results of the present study, PTH may be a useful biomarker for detection and assessment of right HF.

Sevoflurane depresses neurons in the medial parabrachial nucleus by potentiating postsynaptic GABAA receptors and background potassium channels.

Despite persistent clinical use for over 170 years, the neuronal mechanisms by which general anesthetics produce hypnosis remain unclear. Previous studies suggest that anesthetics exert hypnotic effects by acting on endogenous arousal circuits. Recently, it has been shown that the medial parabrachial nucleus (MPB) is a novel wake-promoting component in the dorsolateral pons. However, it is not known whether and how the MPB contributes to anesthetic-induced hypnosis. Here, we investigated the action of sevoflurane, a widely used volatile anesthetic agent that best represents the drug class of halogenated ethers, on MPB neurons in mice. Using in vivo fiber photometry, we found that the population activities of MPB neurons were inhibited during sevoflurane-induced loss of consciousness. Using in vitro whole-cell patch-clamp recordings, we revealed that sevoflurane suppressed the firing rate of MPB neurons in concentration-dependent and reversible manners. At a concentration equal to MAC of hypnosis, sevoflurane potentiated synaptic GABAA receptors (GABAA-Rs), and the inhibitory effect of sevoflurane on the firing rate of MPB neurons was completely abolished by picrotoxin, which is a selective GABAA-R antagonist. At a concentration equivalent to MAC of immobility, sevoflurane directly hyperpolarized MPB neurons and induced a significant decrease in membrane input resistance by increasing a basal potassium conductance. Moreover, pharmacological blockade of GABAA-Rs in the MPB prolongs induction and shortens emergence under sevoflurane inhalation at MAC of hypnosis. These results indicate that sevoflurane inhibits MPB neurons through postsynaptic GABAA-Rs and background potassium channels, which contributes to sevoflurane-induced hypnosis.

Ablation of olfactory bulb glutamatergic neurons induces depressive-like behaviors and sleep disturbances in mice.

RATIONALE: Major depression is a serious, but common, psychological disorder, which consists of a long-lasting depressive mood, feelings of helplessness, anhedonia, and sleep disturbances. It has been reported that rats with bilateral olfactory bulbectomies (OBXs) exhibit depressive-like behaviors which indicates that the olfactory bulb (OB) plays an important role in the formation of depression. However, which type of OB neurons plays an important role in the formation of depression remains unclear. OBJECTIVE: To determine the role of OB neuronal types in depression and related sleep-wake dysfunction. METHODS: Firstly, we established and evaluated a conventional physical bilateral OBX depression model. Secondly, we used chemical methods to ablate OB neurons, while maintaining the original shape, and evaluated depressive-like behaviors. Thirdly, we utilized AAV-flex-taCasp3-TEVp and transgenetic mice to specifically ablate the OB GABAergic or glutamatergic neurons, then evaluated depressive-like behaviors. RESULTS: Compared with measured parameters in sham mice, mice with OBXs or ibotenic acid-induced OB lesions exhibited depressive-like behaviors and sleep disturbances, as demonstrated by results of depressive-like behavior tests and sleep recordings. Selective lesioning of OB glutamatergic neurons, but not GABAergic neurons induced depressive-like behaviors and increased rapid eye movement sleep during the light phase of the circadian cycle. CONCLUSIONS: These results indicate that OB glutamatergic neurons play a key role in olfactory-related depression and sleep disturbance.

Glutamate Activates the Histaminergic Tuberomammillary Nucleus and Increases Wakefulness in Rats.

Glutamate is the major excitatory neurotransmitter in the brain and plays an essential role in regulating wakefulness. Histaminergic neurons, which are exclusively localized in the tuberomammillary nucleus (TMN) of the hypothalamus, have a pivotal role in the regulation of sleep-wake patterns by sending widespread projections into many brain areas implicated in sleep-wake control. The role of glutamate in histaminergic neurons within the TMN and the resulting sleep-wake profile remains unknown. We found that glutamate, NMDA, AMPA or dihydrokainate, a glutamate-uptake inhibitor, dose-dependently increased wakefulness when microinjected into the rat TMN. Glutamate, NMDA, and AMPA also increased the firing rate of action potentials in TMN histaminergic neurons. The arousal-promoting effect of glutamate was inhibited by NMDA and histamine H1 receptor antagonists. Furthermore, MK-801, an NMDA receptor antagonist, inhibited the firing rate of histaminergic neurons and increased non-rapid eye movement sleep after microinjection into rat TMN. Taken together, these findings demonstrated that glutamate activated histaminergic neurons in the TMN and increased wakefulness in rats, possibly via the action of NMDA and histamine H1 receptors.