A novel low-cost electrode for recording the local field potential of freely moving rat's brain.

Local field potentials (LFPs) are involved in almost all cognitive activities of animals. Several kinds of recording electrodes are used for recording LFPs in freely moving animals, including commercial and homemade electrodes. However, commercial recording electrodes are expensive, and their relatively fixed size often causes a steric hindrance effect, especially when combining deep brain stimulation (DBS) with LFP recording, which may not always satisfy the aim of researchers. Currently, an increasing number of researchers are designing their own recording electrodes to lower research costs. Nevertheless, there is no simple universal method to produce low-cost recording electrodes with a specific size according to the target brain area. Thus, we developed a simple method for quickly producing low-cost multiple-channel recording electrodes. To inspect the effectiveness of our self-designed electrode, LFPs were recorded in a Parkinson's disease (PD) rat model, and an electrical stimulation electrode was implanted into the subthalamic nucleus to verify the space-saving ability of the self-designed recording electrode. The results showed that <30 min was needed to prepare an electrode and that the electrode materials cost <5 dollars. Further investigations showed that our electrode successfully recorded the beta oscillations (12-40 Hz) in the PD rat model. Thus, this method will greatly reduce the cost of recording electrodes and save time for researchers. Additionally, the small size of the electrode will further facilitate DBS research.

Comparative Analysis of 95 Patients with Different Severity in the Early Outbreak of COVID-19 in Wuhan, China.

OBJECTIVE: To explore the clinical characteristics of patients with different severity in the early outbreak of COVID-19, hoping to provide reference for clinical diagnosis and treatment. METHODS: We retrospectively analyzed the clinical data of 95 COVID-19 patients in Wuhan Red Cross Hospital of China from January 17 to February 13, 2020. All patients were investigated with epidemiological questionnaires. Outcomes were followed up until April 1, 2020. RESULTS: There were 53 males and 42 females, aged 22-84 years (mean 57.3 years). Clinical classification included 54 cases of common type, 27 cases of severe type, and 14 cases of critical type. Six patients had been exposed to the local Huanan seafood market. There were 38 clusters of COVID-19, including 27 family clusters and 11 work unit clusters. Common symptoms included fever (86 (90.5%) of 95), cough (73 (76.8%)), and fatigue (50 (52.6%)). Laboratory findings showed that the most common abnormalities were lymphopenia (75 (78.9%)), elevated D-dimer (60 (63.2%)), and elevated C-reactive protein (56 (58.9%)) on admission. All patients had abnormal chest computed tomography, showing patchy shadows or ground-glass opacities. Severe and critical cases were older, more likely to have shortness of breath, more likely to have underlying comorbidities, and more likely to have abnormal laboratory findings than common cases. The prognosis of patients with different degrees of severity was significantly different. All common and severe patients (100%) were cured and discharged from the hospital, while 10 (71.4%) of 14 critical patients died. CONCLUSIONS: COVID-19 has fast transmission speed and high pathogenicity. We must assess the severity of the disease and take corresponding treatment measures as early as possible.

A Standardized Anxiety Quotient in Elevated Open Platform Task Quantifies Rodent Anxiogenic Tendency with Improved Reliability and Sensitivity.

Sensitivity and reliability of animal behavioral assessment methods are critical for successful translation of in vitro findings to in vivo. Here we report a data transformation process in the elevated open platform task that generates a novel parameter, namely peak tolerance of fear (PTF) or its inversely correlated equivalent of anxiety quotient (AQ), to measure anxiogenic tendency in rodent. As compared to traditional parameters such as travel distance, time, or entries, PTF or AQ displays largely reduced data dispersion not only ingroup but also cross-study and cross-cohort, therefore representing a significant improvement of the methodology for rodent anxiety assessment.

Quinacrine pretreatment reduces microwave-induced neuronal damage by stabilizing the cell membrane.

Quinacrine, widely used to treat parasitic diseases, binds to cell membranes. We previously found that quinacrine pretreatment reduced microwave radiation damage in rat hippocampal neurons, but the molecular mechanism remains poorly understood. Considering the thermal effects of microwave radiation and the protective effects of quinacrine on heat damage in cells, we hypothesized that quinacrine would prevent microwave radiation damage to cells in a mechanism associated with cell membrane stability. To test this, we used retinoic acid to induce PC12 cells to differentiate into neuron-like cells. We then pretreated the neurons with quinacrine (20 and 40 mM) and irradiated them with 50 mW/cm2 microwaves for 3 or 6 hours. Flow cytometry, atomic force microscopy and western blot assays revealed that irradiated cells pretreated with quinacrine showed markedly less apoptosis, necrosis, and membrane damage, and greater expression of heat shock protein 70, than cells exposed to microwave irradiation alone. These results suggest that quinacrine stabilizes the neuronal membrane structure by upregulating the expression of heat shock protein 70, thus reducing neuronal injury caused by microwave radiation.

Postnatal dysregulation of Notch signal disrupts dendrite development of adult-born neurons in the hippocampus and contributes to memory impairment.

Deficits in the Notch pathway are involved in a number of neurologic diseases associated with mental retardation or/and dementia. The mechanisms by which Notch dysregulation are associated with mental retardation and dementia are poorly understood. We found that Notch1 is highly expressed in the adult-born immature neurons in the hippocampus of mice. Retrovirus mediated knockout of notch1 in single adult-born immature neurons decreases mTOR signaling and compromises their dendrite morphogenesis. In contrast, overexpression of Notch1 intracellular domain (NICD), to constitutively activate Notch signaling in single adult-born immature neurons, promotes mTOR signaling and increases their dendrite arborization. Using a unique genetic approach to conditionally and selectively knockout notch 1 in the postnatally born immature neurons in the hippocampus decreases mTOR signaling, compromises their dendrite morphogenesis, and impairs spatial learning and memory. Conditional overexpression of NICD in the postnatally born immature neurons in the hippocampus increases mTOR signaling and promotes dendrite arborization. These data indicate that Notch signaling plays a critical role in dendrite development of immature neurons in the postnatal brain, and dysregulation of Notch signaling in the postnatally born neurons disrupts their development and thus contributes to the cognitive deficits associated with neurological diseases.

Suppression of Bim by microRNA-19a may protect cardiomyocytes against hypoxia-induced cell death via autophagy activation.

Microvascular obstruction (MO), one of unfavorable complications of percutaneous coronary intervention (PCI), is responsible for the lost benefit of reperfusion therapy. Determination of microRNA-19a, a member of the miR-17-92 cluster, using quantitative real-time polymerase chain reaction (PCR) revealed notably down-regulated microRNA-19a, in myocardium with MO. Nonetheless, the role of miR-19a in MO and the underlying mechanism remains to be elucidated. To this end, an in vitro microembolization model in cardiomyocytes was used. Our data revealed that hypoxic exposure prompted cardiomyocyte apoptosis in a time-dependent manner accompanied by reduced miR-19a. miR-19a overexpression clearly ameliorated hypoxia-induced cell death (necrosis and apoptosis), at least in part, through switching on autophagy. Further dual-luciferase reporter assay and immunoblotting studies demonstrated that miR-19a-induced cytoprotection might be achieved in part through modulation of the specific target Bcl-2 interacting mediator of cell death, Bim, an apoptotic activator. Bim sufficiently interfered with miR-19a-induced LC3 conversion and increased cardiomyocyte apoptosis under hypoxia. Moreover, cardiomyocytes pretreated with 3-methyladenine conferred resistance to the cytoprotective effect of miR-19a and displayed notably increased TUNEL staining and caspase-3 activity. In conclusion, miR-19a protected cardiomyocytes against hypoxia-induced lethality at least in part via Bim suppression and subsequently autophagy activation.

Nonviral Gene Therapy of the Nervous System: Electroporation.

Electroporation has been widely used to efficiently transfer foreign genes into the mammalian central nervous system (CNS), and thus plays an important role in gene therapeutic studies on some brain disorders. A lot of work concerning electroporation is focused on gene transfer into rodent brains. This technique involves an injection of nucleic acids into the brain ventricle or specific area and then applying appropriate electrical field to the injected area. Here, we briefly introduced the advantages and the basic procedures of gene transfer into the rodent brain using electroporation. Better understanding of electroporation in rodent brain may further facilitate gene therapeutic studies on brain disorders.

Nerve growth factor promotes human sperm motility in vitro by increasing the movement distance and the number of A grade spermatozoa.

Nerve growth factor (NGF) was first found in the central nervous system and is now well known for its multiple pivotal roles in the nervous system and immune system. However, more and more evidences showed that NGF and its receptors TrkA and p75 were also found in the head and tail of spermatozoa, which indicate the possible effect of NGF on the sperm motility. Nevertheless, the exact role of NGF in the human sperm motility remains unclear until now. In this study, we investigated the effect of NGF on human sperm motility, and the results showed that NGF could promote human sperm motility in vitro by increasing the movement distance and the number of A grade spermatozoa. Further analysis demonstrated that NGF promoted the sperm motility in a dose-dependent manner in vitro. These results may facilitate the further studies on human fertility and assisted reproduction techniques.

Enhanced hypoxia-inducible factor (HIF)-1α stability induced by 5-hydroxymethyl-2-furfural (5-HMF) contributes to protection against hypoxia.

We first reported the role of 5-hydroxymethyl-2-furfural (5-HMF) against hypoxia. Here, we studied the mechanism by using oxygen-dependent degradation domain (ODD)-Luc mice, which are a useful model to probe the stabilization of hypoxia-inducible factor 1α (HIF-1α). Compared with three other compounds that have been reported to have a role in stabilizing HIF-1α, 5-HMF caused stronger bioluminescence, which is indicative of HIF-1α stability in the brain and kidney of ODD-Luc mice. We further demonstrated that the HIF-1α protein accumulated in response to 5-HMF in the brains and kidneys of these mice, as well as in PC12 cells. Additionally, 5-HMF promoted the nuclear translocation of HIF-1α and the transcriptional activity of HIF-1, which was evaluated by detecting vascular endothelial growth factor (VEGF ) mRNA expression. These results suggest that 5-HMF stabilized HIF-1α and increased its activity. Considering the role of proline hydroxylases (PHDs) in negatively regulating HIF-1α stability, we explored whether 5-HMF interacts with the substrates and cofactors of PHDs, such as 2-oxoglutarate (2-OG), Fe(2+) and vitamin C (VC), which affects the activity of PHDs. The result revealed that 5-HMF did not interact with Fe(2+) or 2-OG but interacted with VC. This interaction was confirmed by subsequent experiments, in which 5-HMF entered into cells and reduced the VC content. The enhanced stability of HIF-1α by 5-HMF was reversed by VC supplementation, and the improved survival of mice caused by 5-HMF under hypoxia was abrogated by VC supplementation. Thus, we demonstrated for the first time that 5-HMF increases HIF-1α stability by reducing the VC content, which mediates the protection against hypoxia.

Progress of in vivo electroporation in the rodent brain.

In vivo electroporation is one of the most efficient methods for introducing the nucleic acids into the target tissues, and thus plays a pivotal role in gene therapeutic studies. In vivo electroporation in rodent brains is often involved in injection of nucleic acids into the brain ventricle or specific area and then applying appropriate electrical field to the correct area. Better understanding of the progress of electroporation in rodent brain may further facilitate gene therapeutic studies on some brain disorders. For this purpose, we briefly summarized the advantages, the procedures and recent progress of transferring nucleic acids into the rodent brain using in vivo electroporation.

[The effects of autophagy on cell survival under different hypoxia].

OBJECTIVE: To investigate the regulation of different hypoxia on cell survival and autophagy. METHODS: PC12 cells were treated with different hypoxia. The cell survival was measured by MTT assay, expressions of LC3 and p62 were marked for autophagy detected by Western Blot, and the level of reactive oxygen species (ROS) was analyzed by flow cytometry. RESULTS: The cell viability was different under different hypoxia: moderate hypoxia promoted cell viability, and severe hypoxia caused a decrease in cell viability; autophagy marker molecules, p62 and LC3-II expressions were different: moderate hypoxia increased p62 and LC3-II expressions, in contrast, severe hypoxia led to the decrease of p62 and LC3-II expressions; compared to normoxia, moderate hypoxia did not change the levels of ROS, while severe hypoxia increased the levels; 3-MA, the inhibitor of autophagy, elevated the levels of ROS in the three oxygen concentrations, additionally, the increased amplitudes in the moderate and severe hypoxia groups were higher than that in the normoxia group. CONCLUSION: Moderate hypoxia promotes cell survival, severe hypoxia causes the cell death, and the autophagy activity may mediate the effects of different hypoxia.

Efficient gene transfer into neonatal mouse brain using electroporation.

In vivo electroporation works as an effective method to transfer exogenous genes into postnatal rodent forebrain. Nevertheless, two deficiencies were found in the reported methods. First, surgical operation brings unnecessary trauma to newborn pups. Second, the procedure was complicated and the transfection efficiency was relatively low. Here we improved the previous electroporation method and make it more simple and efficient. The pulse voltage was decreased to 90 v. DNA injection into one pup's forebrain could be completed within 30 s without any surgical operation. More than 94% of injected neonates survived. Almost 100% of the survivors expressed the introduced gene and the expression persists as long as 20 days after injection. Thus, this method offers a powerful new way for gene function study in postnatal neurogenesis and neural development.

[Effect of quinacrine on inflammatory reaction of blood system induced by microwave irradiation].

This work was aimed to investigate the effect of quinacrine on peripheral granulocytes and lymphocytes, interleukin 1 (IL-1) and interleukin 6 (IL-6) in peripheral blood serum of inflammatory reaction induced by microwave irradiation, and observe the protective effect of quinacrine against microwave irradiation injury. BALB/c mice were suffered from microwave irradiation with the total intensity of 50 mW/cm(2) for 30 minutes, at 1 hour before irradiation quinacrine (12.6 mg/kg or 50.4 mg/kg) was orally administrated. Mice received same volume of water for injection instead of quinacrine were named as microwave irradiation group (MR group), and mice received no microwave irradiation but stayed in microwave irradiation environment also for 30 min were set as control. After microwave irradiation, mice were sacrificed and peripheral blood cells were analyzed with cytoanalyzer, and mice serum interleukin-1ß, interleukin-6 were detected by radioimmunoassay. The results showed that microwave irradiation increased the count of peripheral granulocytes and lymphocyte along with prolongation of time, while the increase of these cells in mice administrated quinacrine was markedly delayed. The level of IL-1ß in serum of mice was significantly increased after 1 day of microwave irradiation (50 mW/cm(2)), and recovered to normal level after 7 days. The 2 concentrations of quinacrine (12.6 mg/kg, 50.4 mg/kg) could suppress level of IL-1ß in serum induced by microwave irradiation. The level of IL-6 in serum of mice was gradually increased after microwave irradiation with intensity of 50 mW/cm(2) for 7 days, but quinacrine administration could delay the rise of IL-6 level, specially within time of 2 days. It is concluded that the quinacrine administration can delay the increase of peripheral granulocytes and lymphocytes inducted by microwave irradiation, and may partially suppress the rise of IL-1ß and IL-6 in serum. The results of this study suggest that the quinacrine can provide some protective effect against microwave irradiation injury.

DIXDC1 promotes retinoic acid-induced neuronal differentiation and inhibits gliogenesis in P19 cells.

Human DIXDC1 is a member of Dishevelled-Axin (DIX) domain containing gene family which plays important roles in Wnt signaling and neural development. In this report, we first confirmed that expression of Ccd1, a mouse homologous gene of DIXDC1, was up-regulated in embryonic developing nervous system. Further studies showed that Ccd1 was expressed specifically in neurons and colocalized with early neuronal marker Tuj1. During the aggregation induced by RA and neuronal differentiation of embryonic carcinoma P19 cells, expressions of Ccd1 as well as Wnt-1 and N-cadherin were dramatically increased. Stable overexpression of DIXDC1 in P19 cells promoted the neuronal differentiation. P19 cells overexpressing DIXDC1 but not the control P19 cells could differentiate into Tuj1 positive cells with RA induction for only 2 days. Meanwhile, we also found that overexpression of DIXDC1 facilitated the expression of Wnt1 and bHLHs during aggregation and differentiation, respectively, while inhibited gliogenesis by down-regulating the expression of GFAP in P19 cells. Thus, our finding suggested that DIXDC1 might play an important role during neurogenesis, overexpression of DIXDC1 in embryonic carcinoma P19 cells promoted neuronal differentiation, and inhibited gliogenesis induced by retinoic acid.