Elevated serum LDL-C increases the risk of Lewy body dementia: a two-sample mendelian randomization study.

BACKGROUND: Lewy body dementia (LBD) ranks second among prevalent neurodegenerative dementias. Previous studies have revealed associations of serum lipid measures with several neurodegenerative diseases. Nevertheless, the potential connection between serum lipids and LBD remains undetermined. In this study, Mendelian randomization (MR) analyses were carried out to assess the causal relationships of several serum lipid measures with the risk of developing LBD. METHODS: Genome-wide association study (GWAS) data for serum lipids and LBD in European descent individuals were acquired from publicly available genetic summary data. A series of filtering procedures were conducted to identify the genetic variant candidates that are related to serum lipids, including high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). The causal effects were primarily determined through inverse-variance weighting (IVW)-based analyses. RESULTS: Neither TG (odds ratio [OR] = 1.149; 95% confidence interval [CI], 0.887-1.489; P = 0.293) nor HDL-C (OR = 0.864; 95% CI, 0.718-1.041; P = 0.124) had causal effects on LBD. However, a causal relationship was identified between LDL-C and LBD (OR = 1.343; 95% CI, 1.094-1.649; P = 0.005), which remained significant (OR = 1.237; 95% CI, 1.015-1.508; P = 0.035) following adjustment for HDL-C and TG in multivariable MR. CONCLUSIONS: Elevated serum LDL-C increases the risk of LBD, while HDL-C and TG have no significant causal effects on LBD.

Blink reflex: A practical test to evaluate the trigeminal nerve injury following percutaneous balloon compression for the treatment of trigeminal neuralgia.

OBJECTIVE: To evaluate the blink reflex (BR) in estimating the potential injury of trigeminal nerve following percutaneous balloon compression (PBC) surgery, and to determine the association between BR alterations and early surgical outcomes. METHODS: In this single-center, prospective before-and-after study, a total of 74 patients who had primary trigeminal neuralgia and scheduled for PBC between October 2020 and June 2021 were prospectively included. BR testing and facial sensory assessment were performed pre- and post-PBC. The latency and the area under the curve (AUC) of pre- and postoperative R1 (R1pre /R1post ) and R2 (R2pre /R2post ) were measured. RESULTS: The BR components were noticeably delayed or diminished following PBC. R1post was elicited in only 26 patients, and absent in 48 patients. The residual R1post had markedly reduced AUC (median difference [Hodges-Lehmann]: -59.5, 95% confidence interval [CI]: -217.5 to -6.9, p = 0.023). Compared with R2pre , the latency of R2post was considerably delayed (mean difference: 4.3, 95% CI: 2.9 to 5.7, p < 0.001) and the AUC was greatly suppressed (median difference [Hodges-Lehmann]: -388.4, 95% CI: -548.4 to -259.5, p < 0.001). After PBC, 58 patients had immediate total pain relief, and 16 had partial relief. The absence of R1post was found in 46 of 58 (79.3%) patients with complete remission, whereas in only 2 of 16 (12.5%) patients with partial relief. Association analysis showed that the absence of R1post was strongly associated with total pain relief (46/58 [79.3%] vs. 2/16 [12.5%], odds ratio [OR]: 26.8, 95% CI: 5.4 to 134.5, Cramér's V: 0.6, p < 0.001). The latency of R2post in patients with total relief was significantly delayed (mean difference: 2.5, 95% CI: 0.3 to 4.6, p = 0.028). Patients experienced graded facial numbness after PBC, of whom 31 reported mild numbness (Grades I-II) and 43 reported more severe numbness (Grades III-IV). The absence of R1post was significantly associated with facial numbness severity, 33/43 (76.7%) in Grades III-IV vs. 15/31 (48.4%) in Grades I-II (OR: 0.284, 95% CI: 0.105 to 0.771, Cramér's V: 0.3, p = 0.012). In patients with more severe numbness, the latency of R2post was significantly delayed (mean difference: 2.7, 95% CI: 0.1 to 5.3, p = 0.043), and the reduction of AUC was much greater (median difference [Hodges-Lehmann]: 17.2, 95% CI: 0.5 to 35.4, p = 0.041). CONCLUSION: Both R1 and R2 were significantly diminished after PBC and these alterations were associated with early surgical outcomes, suggesting that the BR is useful in evaluating trigeminal injury following PBC and could provide objective information about early prognosis.

Nickel Foam Supported NiO@Ru Heterostructure Towards High-Efficiency Overall Water Splitting.

Electrocatalytic water splitting for hydrogen production from renewable energy requires the innovation of electrocatalysts with high activity and low cost. In this work, densely packed NiO@Ru nanosheets were fabricated on the surface of Ni foam through a two-step method of Ni(OH)2 growth followed by Ru deposition. Through pair distribution function analysis from selected-area electron diffraction and X-ray photoelectron spectroscopy, the interface structure feature is revealed as a thin layer of perovskite NiRuO3 sandwiched between NiO and Ru. The electrode exhibits high activity and durability for HER and OER, delivering a current density of 10 mA cm-2 at a voltage of 1.55 V for overall water splitting in 1 M KOH. The excellent performance can be attributed to the intimate interface contact of NiO and Ru in addition to low charge transfer resistance and super-hydrophilic surface structure, as verified by the electrochemical impedance spectroscopy and contact-angle measurement.

Angiomotin-like 1 plays a tumor-promoting role in glioma by enhancing the activation of YAP1 signaling.

Angiomotin-like 1 (AMOTL1) is reportedly a pivotal tumor-associated protein that is strongly associated with the tumorigenesis of multiple malignant tumors. However, the issue of whether AMOTL1 plays a role in the tumorigenesis of glioma remains unclear. The aim of this work was to explore the possible relationship between AMOTL1 and glioma progression. Results demonstrated that high levels of AMOTL1 in glioma tissues were associated with a reduced survival rate in patients with glioma. Cellular functional assays revealed that silencing of AMOTL1 in glioma cell lines substantially decreased cell proliferation and invasion and increased cell apoptosis. Further investigation revealed that silencing of AMOTL1 inhibited the activation of yes-associated protein 1 (YAP1) and decreased the expression of YAP1 target genes. Reactivation of YAP1 reversed AMOTL1-silencing-induced antitumor effects, whereas inhibition of YAP1 abolished AMOTL1-overexpression-induced tumor-promoting effects in glioma cells. Silencing of AMOTL1 also retarded the growth of glioma cell-derived xenograft tumors in vivo. In conclusion, these findings suggested that AMOTL1 may exert a tumor-promoting function in glioma by enhancing the activation of YAP1 signaling. This work suggested AMOTL1 as a potential target for the development of antiglioma therapy.

Anatomical deviations of vertebral artery in hemifacial spasm: a quantitative study.

PURPOSE: There exist different opinions on whether the anatomical laterality of vertebral artery (VA) is related to the unilateral onset of hemifacial spasm (HFS). In this study, we intended to qualitatively explore the potential correlation between the anatomical deviations of VA and the clinical characteristics of HFS. METHODS: Two hundred and forty patients who underwent microvascular decompression for HFS between January 2018 and December 2019 were recruited. Clinical data including medical records and preoperative MRI images were retrospectively reviewed. A score system was specially designed for VAs to illustrate their distribution, and a score-weighted cross-sectional area of VA was proposed to represent the relative thickness of VA on each side. Then, the anatomical deviations of VA were comparatively analyzed between the symptomatic side and asymptomatic side and between VA-involved cases and non-VA-involved cases. RESULTS: The score and weighted cross-sectional area (WCSA) of VA in symptomatic side were significantly greater than those in asymptomatic side (P = 0.000, P = 0.000). And in symptomatic side, the score and WCSA of VA in VA-involved cases were significantly greater than those in non-VA-involved cases (P = 0.000). Moreover, with higher score (P = 0.000) and greater WCSA (P = 0.001) on the left side, the VA-involved cases showed a preference (74%) of left HFS. CONCLUSIONS: In HFS, the symptomatic side tends to have an ipsilaterally deviated and relatively larger VA, especially in VA-involved cases. And it is the VA-involved cases that are prone to have a prevalence of left HFS, but not the non-VA-involved cases.

MicroRNA-378 regulates epithelial-mesenchymal transition and metastasis of melanoma by inhibiting FOXN3 expression through the Wnt/ß-catenin pathway.

MicroRNAs (miRNAs) participate in the development and progression of melanoma. However, while dysregulation of microRNA-378 (miR-378) has been seen in various cancer types, its clinical importance and function in melanoma are poorly elucidated. In this work, miR-378 expression in melanoma and in adjacent non-cancerous tissue was evaluated with a quantitative real-time polymerase chain reaction. A series of assays (wound healing, Transwell, and nude mouse subcutaneous tumor model) were used to investigate the implications of abnormal miR-378 regulation on melanoma cell migration and invasion in vitro, and on tumorigenicity in vivo. Prediction and conformation of the miR-378 target gene was undertaken using bioinformatic analysis and luciferase reporter system. Expression of miR-378 was often increased in melanoma, and shown to potentiate its migration, invasion, and tumorigenicity. miR-378 acted, at least partially, through inhibition of the potential target FOXN3 and via Wnt/ß-catenin pathway activation. The findings indicate that miR-378 triggers melanoma development and progression. This miRNA could be a novel diagnostic and prognostic biological marker and provide utility for targeted treatment of melanoma.

Ultrathin Nanotubes of Bi5O7I with a Reduced Band Gap as a High-Performance Photocatalyst.

Bismuth oxyhalide (Bi-O-X) is a group of layered semiconductors, which are promising candidates for photocatalysis due to their inherent internal electric field and adjustable band gap through composition and morphology control. Bismuth-rich Bi-O-X has improved stability and advantageous band structure compared to those of Bi-O-X and hence has attracted an increasing amount of research interest. In this work, ultrathin nanotubes of Bi5O7I with a 5 nm diameter and a 1 nm wall are obtained through a hydrothermal method while the phase and morphology of the products are regulated by the pH values and polyvinylpyrrolidone (PVP) concentration of the reaction system, of which the products can be tuned from BiOI nanosheets to Bi5O7I nanobelts and ultrathin Bi5O7I nanotubes. PVP and pH control is important to the formation of the nanotubes as formation occurs via a PVP-guided oriented attachment from primary nanoparticles of Bi5O7I. The poorly crystalline and porous structure of the resultant bismuth-rich ultrathin nanotubes not only exposes more surface atoms but also exhibits a highly reduced conduction band minimum. The resultant band gap of 2.39 eV (as compared to 3.20 eV for the nanobelts) arises from the undercoordinated bismuth centers brought about by the rich oxygen vacancies in the nanotubes. The largely reduced band gap effectively enhances visible-light absorption, while the short charge-diffusion length of the nanotubes further reduces the charge-carrier loss in recombination.

microRNA-216b inhibits cell proliferation and migration in human melanoma by targeting FOXM1 in vitro and in vivo.

MicroRNAs (miRNAs) play an increasingly important role in cancer growth by coordinately suppressing genes that control cell migration, proliferation, and invasion. The above results can be achieved through the regulation of gene expression by miRNAs by suppressing translation or the direct sequence-specific degradation of the targeted mRNA. In the present study, we indicate that the expression of miR-216b could be effectively repressed both in human melanoma tissues through a comparison with primary melanoma and in human melanoma cell lines through a comparison with a normal human keratinocyte line. Moreover, miR-216b induced a clear decrease in melanoma cell proliferation and migration in vitro. Forkhead box M1 (FOXM1) was confirmed as a target gene of miR-216b, and the overexpression of miR-216b markedly repressed the luciferase activity of reporter plasmids containing the FOXM1 3'-UTR (untranslated region). Furthermore, miR-216b suppressed melanoma cell growth in nude mice in vivo, with the effects of miR-216b overexpression on melanoma cell growth and proliferation reversed by FOXM1 overexpression. The results demonstrated that miR-216b is a tumor suppressor in melanoma, identified the FOXM1 signaling pathway as a target of miR-216b action, and suggested a potential therapeutic role for miR-216b in melanoma.

PARP3 interacts with FoxM1 to confer glioblastoma cell radioresistance.

Poly(ADP-ribose) polymerase 3 (PARP3), a critical player in cellular response to DNA double-strand breaks (DSBs), plays an essential role in the maintenance of genome integrity. However, the role of PARP3 in tumorigenesis especially in glioblastoma remains largely unknown. In the present study, we found that the mRNA and protein levels of PARP3 were upregulated in primary glioblastoma tissues. Knockdown of PARP3 expression by lentivirus-based shRNA decreased cell glioblastoma proliferation and inhibited tumor growth in vivo by using a xenograft mouse model. Furthermore, we found that silencing the expression of PARP3 resulted in a synergistic radiosensitizing effect when combined with radiotherapy in glioblastoma cell lines. At the molecular level, we found that PARP3 interacted with FoxM1 to enhance its transcriptional activity and conferred glioblastoma cell radioresistance. Thus, our data suggest that PARP3 could be a therapeutic target to overcome radioresistance in glioblastoma.

HDAC4-mediated Deacetylation of Glutaminase Facilitates Glioma Stemness.

BACKGROUND: Inhibiting cancer metabolism via glutaminase (GLS) is a promising strategy to disrupt tumor progression. However, the mechanism regarding GLS acetylation remains largely unknown. METHODS: Mitochondrial protein isolation and glutaminase activity assay were used to examine GLS activity. RT-qPCR, western blot, sphere-formation, ALDH activity, and tumor-initiating assays were performed to evaluate the alteration of cell stemness. Co-IP and rescuing experiments were conducted to explore the underlying mechanisms. RESULTS: In this study, we demonstrated that GLS acetylation is a vital post-translational modification that inhibits GLS activity in glioma. We identified GLS as deacetylated by HDAC4, a class II deacetylase. GLS acetylation stimulated the interaction between GLS and SIRT5, thereby promoting GLS ubiquitination and inhibiting GLS activity. Furthermore, GLS overexpression suppressed the stemness of glioma cells, which was rescued by the deacetylation of GLS. CONCLUSION: Our findings reveal a novel mechanism of GLS regulation by acetylation and ubiquitination that participate in glioma stemness.>.

C-Fos-activated circRPPH1 contributes to glioma stemness.

OBJECTIVE: Cancer stem cells or cancer stemness has been confirmed to a major obstacle for glioma progression and it has also been reported that circRNAs play an important part in cancer progression. This study mainly focuses on revealing the role of circRPPH1 and the underlying mechanisms in glioma cell stemness. METHODS: In vitro experiment including RT-qPCR, Western blot, sphere-formation analysis, and ALDH1 activity, and in vivo tumorigenesis experiments were performed to evaluate the effects of circRPPH1 on glioma cell stemness. Luciferase reporter, ChIP, and DNA pull-down analysis were used to reveal the underlying mechanisms. RESULTS: It was found that circRPPH1 level was upregulated in glioma cell spheres and facilitated the stemness of glioma cells; C-FOS transcriptionally activated circRPPH1 expression via directly binding to circRPPH1 promoter in glioma cells. Moreover, circRPPH1 promoted the stemness of glioma cells dependent on c-FOS-mediated transcriptional activation. CONCLUSIONS: This study indicates that c-Fos-activated circRPPH1 contributes to glioma stemness and provides a potential target for glioma progression based on the c-FOS/circRPPH1 regulatory axis.

Microstructure and Reasonable Management of the Arachnoid Associated with the Infrafloccular Approach for Microvascular Decompression of the Facial Nerve.

AIM: To understand the arachnoid microstructure during infrafloccular approach for facial nerve microvascular decompression (MVD). MATERIAL AND METHODS: This study recruited 55 patients with hemifacial spasm who underwent MVD. Retrospective analyses of the MVD surgical videos were performed to reveal the arachnoid microstructure during the procedures. Cadaveric head specimens (n=8, on 16 sides) were dissected for observation of the microstructure of the arachnoid in the cerebellopontine angle. RESULTS: The arachnoid membrane surrounding the facio-cochleovestibular and lower cranial nerves forms two arachnoid sheaths. Both arachnoid sheaths contain two parts: the outer membranous and inner trabecular part. The membranous part is an intact and translucent membrane that wraps around nerves. The inner trabecular part is located beneath the membranous part and forms a trabecular network that connects the membranous arachnoid, nerves, and blood vessels to form a physical structure. CONCLUSION: The arachnoid connects the facio-cochleovestibular and lower cranial nerves, blood vessels, and cerebellum as a complex physical entity. Therefore, during MVD surgery, sharply dissecting the arachnoid before retracting the flocculus and relocating the offending vessels helps reduce nerve injury.

Effectiveness of vagus nerve stimulation for drug-resistant generalized epilepsy in children aged six and younger.

BACKGROUND: To explore a novel scoring system to evaluate the efficacy of vagus nerve stimulation (VNS) in children with drug-resistant generalized epilepsy (DRGE) aged six and younger. BASIC PROCEDURES: The data of twelve children with DRGE under the age of 6 years who accepted VNS and have been followed up for at least 3 years were retrospectively reviewed. The outcome was evaluated with the McHugh Classification System and a novel scoring system we proposed. MAIN FINDINGS: Based on the McHugh Classification System, the total response rate was 91.67% (11/12) and the rate of Grade I was 41.67% (5/12). A novel scoring system involving seizure frequency, seizure duration and quality of life (QOL) was proposed, by which the outcome was scored from -3 to 11 and graded from IV to I. Based on the novel scoring system, the total response rate was 91.67% (11/12) and the rate of Grade I was 33.33% (4/12). The incidence of complication was 16.67% (2/12). The efficacy of VNS appeared a gradually improving trend with plateau or fluctuation over time. Shorter course of epilepsy prior to VNS may be related to better outcome. PRINCIPAL CONCLUSIONS: VNS could effectively reduce the seizure frequency and improve the QOL of children with DRGE aged six and younger. The novel scoring system was comprehensive and feasible to evaluate the efficacy of VNS. The time pattern of the long-term efficacy of VNS requires further investigation.

Rab11a in the spinal cord: an essential contributor to complete Freund's adjuvant-induced inflammatory pain in mice.

Inflammatory pain is a commonly observed clinical symptom in a range of acute and chronic diseases. However, the mechanism of inflammatory pain is far from clear yet. Rab11a, a small molecule guanosine triphosphate enzyme, is reported to regulate orofacial inflammatory pain in our previous works. However, the mechanism of Rab11a's involvement in the regulation of inflammatory pain remains obscure. Here, we aim to elucidate the potential mechanisms through which Rab11a contributes to the development of inflammatory pain in the spinal level. It's shown that neurons, rather than glial cells, were the primary cell type expressing Rab11a in the spinal dorsal horn (SDH). After intra-plantar injection of CFA, both the number of Fos/Rab11a-immunopositive neurons and the expression of Rab11a were increased. Administration of Rab11a-shRNA into the SDH resulted in significantly analgesic effect in mice with CFA injection. Application of Rab11a-shRNA also reduced the NMDA receptor-mediated excitatory post-synaptic current (EPSC) and the spike number of neurons in lamina II of the SDH in mice with CFA injection, without affecting the presynaptic glutamate release and the postsynaptic AMPA receptor-mediated EPSC. Our results thus suggest that the enhanced expression of neuronal Rab11a may be important for the process of inflammatory pain in mice with CFA injection, which is likely mediated by Rab11a's potentiation of the competence of post-synaptic NMDAR and spiking of SDH neurons.

Prognostic value of m6A regulators and the nomogram construction in glioma patients.

Although N6-methyladenosine (m6A) has been implicated in various biological functions in human cancers, its role in predicting the prognosis of glioma remains unclear. In this study, the transcriptome expression profiles and the clinical data of 961 patients were derived from the Chinese Glioma Genome Atlas (CGGA). We comprehensively evaluated the association between the expression of m6A regulators and the prognosis of glioma and established a 3-gene (YTHDF2, FTO, and ALKBH5) risk signature using least absolute shrinkage and selection operator (LASSO) analysis. Patients with a high-risk signature had significantly adverse prognoses. Gene set enrichment analysis (GSEA) analysis revealed that the G2M checkpoint, MTORC1 signaling, epithelial mesenchymal transition, and PI3K-AKT-mTOR signaling were significantly enriched in the high-risk group. Univariate and multivariate Cox regression analyses confirmed the independent prognostic value of this risk signature. We then constructed a nomogram for individualized prediction of overall survival (OS) by integrating clinicopathological features (age, World Health Organization [WHO] grade), treatment information (radiotherapy, temozolomide therapy), and m6A risk signature. The calibration curves showed excellent agreement between the predicted and actual probabilities for the 1-, 3-, and 5-year OS, with a C-index of 0.780 in the training cohort and 0.717 in the validation cohort. Altogether, our study elucidated the important role of m6A regulators in glioma prognosis, which is valuable for the selection of therapeutic methods and clinical management of patients with glioma.

Palladium hydride with high-index facets for enhanced methanol oxidation.

Nobel metal catalysts with high-index facets feature a high density of steps and kink sites, which bring about high activity but could be unstable during the electrocatalytic process. Doping with interstitial hydrogen atoms is a unique and effective way to regulate the electronic structure of the host materials. The formation of hydride also helps to stabilize the active sites on the surface of catalysts. Herein, we demonstrate the conformal doping of H atoms into the Pd nanostructure with preferential exposure of {730} facets, forming concave nanocubes of palladium hydride. Compared to the palladium counterparts, the palladium hydride catalysts show enhanced activity and stability in electrocatalytic methanol oxidation, and the structural differences between the Pd and PdH catalysts are revealed by XRD and X-ray photoelectron spectroscopy. Our work presents a powerful strategy for designing durable catalysts with high performance by combining high-index facet with interstitial atom doping.

Facial root entry/exit zone contact in microvascular decompression for hemifacial spasm: a historical control study.

BACKGROUND: Microvascular decompression (MVD) surgery is recognized as an effective treatment for hemifacial spasm (HFS). In MVD surgery, biocompatible materials are usually implanted in situ at the neurovascular conflict site in contact with the offending vessel and the facial root entry/exit zone (REZ). Another procedure of implanting the materials between the responsible vessel and the supraolivary fossa without REZ contact has also been applied. However, it is unclear whether there are any differences between these 2 procedures (REZ-contact procedure vs. REZ-non-contact procedure). Therefore, the aim of the present study was to investigate the effect of the placement of implants (contacting or not contacting the facial REZ) on surgical operations and outcomes. METHODS: A historical control study was performed. Clinical data of HFS patients who underwent MVD between December 2016 and November 2018 were reviewed and categorized into 1 group with the REZ-contact procedure or another group with the REZ-non-contact procedure according to the decompression strategy they received. Clinical demographics, postoperative outcomes, and complications were collected and compared between the two groups. RESULTS: Not all patients are suitable for REZ-non-contact decompression. A total of 205 patients were enrolled: 112 in the REZ-contact group and 93 in the REZ-non-contact group. In the early postoperative period, the complete cure rate in the REZ-non-contact group was significantly higher than that in the REZ-contact group. The reappearance and partial relief rates in the REZ-contact group were significantly higher than those in the REZ-non-contact group. The incidence of short-term neurological complications, especially hearing loss and transient facial palsy, was lower in the REZ-non-contact group (P=0.043). But for long-term follow-up of >1 year, there was no significant difference between the two groups in either curative effects or neurological complications. The operating time for REZ-non-contact decompression was relatively longer than for REZ-contact decompression (P=0.000). An unexpected subdural hemorrhage occurred in the REZ-non-contact group. CONCLUSIONS: REZ-non-contact decompression procedure showed superiority only in short-term postoperative outcomes. Given its limitations and potential risks, the REZ-non-contact procedure can be used as an alternative individualized strategy in MVD, and there is no need to pursue REZ-non-contact during the decompression.

The one-pot synthesis of CuNi nanoparticles with a Ni-rich surface for the electrocatalytic methanol oxidation reaction.

The use of fuel cells is one of the most promising renewable energy strategies, but they still suffer from many limitations. The high mass enthalpy of hydrogen as a fuel comes at the cost of inconveniences and risks associated with storage, transportation and utilization, while the high performance of Pt catalysts in commercial fuel cells is limited by their high cost, low earth abundance, and poor stability as a result of CO intermediate poisoning. To circumvent these dilemmas, direct methanol fuel cells (DMFCs) were developed, using methanol as a fuel and Ni as the anode catalyst. Thanks to the condensed form of the fuel, DMFCs are considered as the most promising fuel-cell solution for portable electronic devices. Usually, other elements have to be introduced into Ni-based catalysts to modify the active sites to provide better alternatives to pristine Ni metal in terms of activity and stability. In this study, we provide a mild synthetic method for the preparation of CuNi alloy nanoparticles. The proper alloying ratio leads to the suitable modification of the electronic structure of Ni, which promotes the MOR catalytic reaction on the NiCu alloy. The NiCu alloy catalyst exhibits a mass current density of 1028 mA mgmetal-1 for the MOR at 1.55 V (vs. RHE), which is among the best values obtained from similarly prepared Ni-based catalysts.

The head fixation based on skull cap: An improved protocol used in single unit recording in the vestibular system.

Single unit recording has an important application in neuroscience, especially in the vestibular system such as visual stabilization, posture maintenance, spatial orientation and cognition. However, single unit recording conducted in living animals is a demanding technique and non-ideal mechanical stability between the recording location of nerve tissues and the tip of microelectrode always results in failure to obtain successful recordings in the vestibular system. In order to improve the mechanical stability during single unit recording, we constructed a novel head fixation method based on skull cap. This article describes in detail how to construct this novel head fixation. Following the step-by-step procedure mentioned in this article will provide a high-quality mechanical stability for single unit recording in the vestibular system, allowing us to successfully record the nonlinear neural dynamic response over a big magnitude motion stimulation. This improvement of head fixation contributes to the in-depth understanding of the vestibular system.

The real identity and sensory overlap mechanism of special vestibular afferent neurons that sense both rotation and linear force.

AIMS: Although the vestibular system has been widely investigated over the past 50 years, there is still an unsolved mystery. Some special vestibular afferent (SVA) neurons responding to both rotation and linear force were found through neurophysiological techniques, however, the sensory overlap mechanism of SVA neurons is still unclear, which may be closely related to vestibular-related diseases. MATERIALS AND METHODS: To address the above-mentioned problem, a cupula buoyancy theory was established in the present study, where SVA neurons were considered semicircular canal afferent (SCCA) neurons. Then labyrinth anatomy and neural response dynamics of vestibular afferent neurons in chinchilla were investigated through vestibular labyrinth reconstruction and single unit recording technique, respectively. KEY FINDINGS: We analyzed the deflections of cupulae under multiple conditions with the help of Amira Software and predicted the neural response law of SCCA neurons to linear force based on the cupula buoyancy theory. Data analysis confirmed that the basic response characteristic of SVA neurons had no significant difference to those of SCCA neurons, but were significantly different from those of otolith afferent neurons. Further, the actual responses of SVA neurons to linear force are completely consistent with our predictions. These results strongly suggest that SVA neurons actually are SCCA neurons, and the cupula buoyancy theory is the key to the sensory overlap mechanism of SCCA neurons. SIGNIFICANCE: Our study revealed the real identity of SVA neurons and provided a reasonable mechanism for sensory overlap of rotation and linear force, which improved our understanding about the vestibular system.