Olfactory three needle regulates the proliferation of olfactory bulb neural stem cells and ameliorates brain injury after subarachnoid hemorrhage by regulating Wnt/β-catenin signaling

Background

Subarachnoid hemorrhage (SAH) is a serious cerebrovascular emergency. The incidence of SAH and hazard ratio of death increase with age.

Objective

In this study, we aimed to observe the effects and potential mechanisms of olfactory three needle (OTN) on cognitive impairment, neuronal activity, and neural stem cell differentiation in SAH rats.

Methods

Sprague-Dawley (SD) rats were randomly divided into five groups: Sham, SAH group, SAH + Nimodipine (NMP) group, and SAH + OTN group. The rats in the SAH + OTN group received the OTN electroacupuncture treatment. For treatment with recombinant DKK1 (a Wnt/β-catenin inhibitor), mice were injected with DKK1.

Results

Our results found that OTN improved cognitive impairment and hippocampal neuron damage in SAH rats. Furthermore, OTN promoted the proliferation of neural stem cells in SAH rats. Mechanistically, OTN activated Wnt/β-catenin signaling in SAH rats, as indicated by the increased expression levels of Wnt1, β-Catenin, LMNB1, and p-GSK-3β. DKK1 reversed the improvement effect of OTN on cognitive impairment and neuronal damage in SAH rats. Meanwhile, DKK1 blocked the promoting effect of OTN on the proliferation of NSCs in SAH rats.

Conclusions

OTN electroacupuncture may be an effective therapeutic strategy for SAH.

Evaluation of specific RBE in different cells of hippocampus under high-dose proton irradiation in rats

The study aimed to determine the specific relative biological effectiveness (RBE) of various cells in the hippocampus following proton irradiation. Sixty Sprague-Dawley rats were randomly allocated to 5 groups receiving 20 or 30 Gy of proton or photon irradiation. Pathomorphological neuronal damage in the hippocampus was assessed using Hematoxylin-eosin (HE) staining. The expression level of NeuN, Nestin, Caspase-3, Olig2, CD68 and CD45 were determined by immunohistochemistry (IHC). The RBE range established by comparing the effects of proton and photon irradiation at equivalent biological outcomes. Proton20Gy induced more severe damage to neurons than photon20Gy, but showed no difference compared to photon30Gy. The RBE of neuron was determined to be 1.65. Similarly, both proton20Gy and proton30Gy resulted in more inhibition of oligodendrocytes and activation of microglia in the hippocampal regions than photon20Gy and photon30Gy. However, the expression of Olig2 was higher and CD68 was lower in the proton20Gy group than in the photon30Gy group. The RBE of oligodendrocyte and microglia was estimated to be between 1.1 to 1.65. For neural stem cells (NSCs) and immune cells, there were no significant difference in the expression of Nestin and CD45 between proton and photon irradiation (both 20 and 30 Gy). Therefore, the RBE for NSCs and immune cell was determined to be 1.1. These findings highlight the varying RBE values of different cells in the hippocampus in vivo. Moreover, the actual RBE of the hippocampus may be higher than 1.1, suggesting that using as RBE value of 1.1 in clinical practice may underestimate the toxicities induced by proton radiation.

SIRT1, a target of miR-708-3p, alleviates fluoride-induced neuronal damage via remodeling mitochondrial network dynamics

INTRODUCTION

Neurological dysfunction induced by fluoride contamination is still one of major concern worldwide. Recently, neuroprotective roles of silent information regulator 1 (SIRT1) focusing on mitochondrial function have been highlighted. However, what roles SIRT1 exerts and the underlying regulative mechanisms, remain largely uncharacterized in such neurotoxic process of fluoride.

OBJECTIVES

We aimed at evaluating the regulatory roles of SIRT1 in human neuroblastoma SH-SY5Y cells and Sprague-Dawley rats with fluoride treatment, and to further identify potential miRNA directly targeting SIRT1.

METHODS

Pharmacological suppression of SIRT1 by nicotinamide (NIC) and promotion of SIRT1 by adenovirus (Ad-SIRT1) or resveratrol (RSV) were employed to assess the effects of SIRT1 in mitochondrial dysfunction induced by fluoride. Also, miRNAs profiling and bioinformatic prediction were used to screen the miRNAs which can regulate SIRT1 directly. Further, chemical mimic or inhibitor of chosen miRNA was applied to validate the modulation of chosen miRNA.

RESULTS

NIC exacerbated defects in mitochondrial network dynamics and cytochrome c (Cyto C) release-driven apoptosis, contributing to fluoride-induced neuronal death. In contrast, the ameliorative effects were observed when overexpressing SIRT1 by Ad-SIRT1 in vitro or RSV in vivo. More importantly, miR-708-3p targeting SIRT1 directly was identified. And interestingly, moreover, treatment with chemically modified miR-708-3p mimic aggravated, while miR-708-3p inhibitor suppressed fluoride-caused neuronal death. Further confirmedly, overexpressing SIRT1 effectively neutralized miR-708-3p mimic-worsened fluoride neuronal death via correcting mitochondrial network dynamics. On contrary, inhibiting SIRT1 counteracted the promotive effects of miR-708-3p inhibitor against neurotoxic response by fluoride through aggravating abnormal mitochondrial network dynamics.

CONCLUSION

These data underscore the functional importance of SIRT1 to mitochondrial network dynamics in neurotoxic process of fluoride and further screen a novel unreported neuronal function of miR-708-3p as an upstream regulator of targeting SIRT1, which has important theoretical implications for a potential therapeutic and preventative target for treatment of neurotoxic progression by fluoride.

The Impact of Cerebral Ischemia on Antioxidant Enzymes Activity and Neuronal Damage in the Hippocampus

Cerebral ischemia and subsequent reperfusion, leading to reduced blood supply to specific brain areas, remain significant contributors to neurological damage, disability, and mortality. Among the vulnerable regions, the subcortical areas, including the hippocampus, are particularly susceptible to ischemia-induced injuries, with the extent of damage influenced by the different stages of ischemia. Neural tissue undergoes various changes and damage due to intricate biochemical reactions involving free radicals, oxidative stress, inflammatory responses, and glutamate toxicity. The consequences of these processes can result in irreversible harm. Notably, free radicals play a pivotal role in the neuropathological mechanisms following ischemia, contributing to oxidative stress. Therefore, the function of antioxidant enzymes after ischemia becomes crucial in preventing hippocampal damage caused by oxidative stress. This study explores hippocampal neuronal damage and enzymatic antioxidant activity during ischemia and reperfusion's early and late stages.

MDMA targets miR-124/MEKK3 via MALAT1 to promote Parkinson's disease progression

BACKGROUND

Parkinson's disease (PD) is a well-known neurodegenerative disease that is usually caused by the progressive loss of dopamine neurons and the formation of Lewy vesicles. 3,4-Methylenedioxymethamphetamine (MDMA) has been reported to cause damage to human substantia nigra neurons and an increased risk of PD, but the exact molecular mechanisms need further investigation.

METHODS

MPTP- and MPP+-induced PD cells and animal models were treated with Nissl staining to assess neuronal damage in the substantia nigra (SN) area; immunohistochemistry to detect TH expression in the SN; TUNEL staining to detect apoptosis in the SN area; Western blotting to detect the inflammatory factors NF-κB, TNF-α, IL-6 and mitogen-activated protein kinase kinase kinase 3 (MEKK3); Griess assay for NO; RT‒qPCR for metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and miR-124 expression; Cell proliferation was assessed by CCK-8. Dual luciferase reporter genes were used to verify targeting relationships.

RESULTS

MDMA promoted MALAT1 expression, and knockdown of MALAT1 alleviated the MDMA-induced inhibition of SH-SY5Y cell proliferation, inflammation, NO release, SN neuronal injury, and TH expression inhibition. Both inhibition of miR-124 and overexpression of MEKK3 reversed the neuroprotective effects exhibited by knockdown of MALAT1.

CONCLUSION

MDMA promotes MALAT1 expression and inhibits the targeted downregulation of MEKK3 by miR-124, resulting in upregulation of the expression of MEKK3 and finally jointly promoting PD progression.

Neuroprotective Effect of Hydrogen Sulfide Subchronic Treatment Against TBI-Induced Ferroptosis and Cognitive Deficits Mediated Through Wnt Signaling Pathway

Emerging evidence shows that targeting ferroptosis may be a potential therapeutic strategy for treating traumatic brain injury (TBI). Hydrogen sulfide (H2S) has been proven to play a neuroprotective role in TBI, but little is known about the effects of H2S on TBI-induced ferroptosis. In addition, it is reported that the Wnt signaling pathway can also actively regulate ferroptosis. However, whether H2S inhibits ferroptosis via the Wnt signaling pathway after TBI remains unclear. In this study, we first found that in addition to alleviating neuronal damage and cognitive impairments, H2S remarkably attenuated abnormal iron accumulation, decreased lipid peroxidation, and improved the expression of glutathione peroxidase 4, demonstrating the potent anti-ferroptosis action of H2S after TBI. Moreover, Wnt3a or liproxstatin-1 treatment obtained similar results, suggesting that activation of the Wnt signaling pathway can render the cells less susceptible to ferroptosis post-TBI. More importantly, XAV939, an inhibitor of the Wnt signaling pathway, almost inversed ferroptosis inactivation and reduction of neuronal loss caused by H2S treatment, substantiating the involvement of the Wnt signaling pathway in anti-ferroptosis effects of H2S. In conclusion, the Wnt signaling pathway might be the critical mechanism in realizing the anti-ferroptosis effects of H2S against TBI. TBI induces ferroptosis-related changes characterized by iron overload, impaired antioxidant system, and lipid peroxidation at the chronic phase after TBI. However, NaHS subchronic treatment reduces the susceptibility to TBI-induced ferroptosis, at least partly by activating the Wnt signaling pathway.

Evaluation of the brain cellular damage during liver transplantations

Background

Neuroinflammation in patients undergoing major surgery can lead to neuronal damage, and neuronal damage can be detected through the measurement of biochemical markers of brain damage. S100 beta (S100 β), neuron-specific enolase (NSE), and glial fibrillary acidic protein (GFAP) levels are considered good biomarkers to detect brain damage that emerged with neurotoxicity.

Aim

To evaluate neuronal damage during liver transplantations.

Materials and Methods

After approval of the ethics committee and patient consents, preoperative and postoperative cognitive functions of 33 patients undergoing liver transplantation were measured using the Mini Mental State Examination (MMSE), whereas simultaneous neuronal damage was evaluated through the measurement of S100β, NSE, and GFAP levels.

Results

There was no statistically significant difference between preoperative and postoperative MMSE. There was a statistically significant decrease in postoperative GFAP (P < 0.05) and a statistically significant increase in NSE (P < 0.05) compared to preoperative values. The decrease in S100β (P > 0.05) level was statistically insignificant.

Conclusions

Neuroprotective approaches in anesthesia protocol protect patients from brain damage during liver transplantation and prevent the development of postoperative cognitive dysfunction. Since the significant increase in NSE levels during liver transplantations was deemed to have been associated with causes other than neuronal damage, NSE should not be evaluated as a marker of brain damage in these operations.

L-2-Hydroxyglutaric Acid Administration to Neonatal Rats Elicits Marked Neurochemical Alterations and Long-Term Neurobehavioral Disabilities Mediated by Oxidative Stress

L-2-Hydroxyglutaric aciduria (L-2-HGA) is an inherited neurometabolic disorder caused by deficient activity of L-2-hydroxyglutarate dehydrogenase. L-2-Hydroxyglutaric acid (L-2-HG) accumulation in the brain and biological fluids is the biochemical hallmark of this disease. Patients present exclusively neurological symptoms and brain abnormalities, particularly in the cerebral cortex, basal ganglia, and cerebellum. Since the pathogenesis of this disorder is still poorly established, we investigated the short-lived effects of an intracerebroventricular injection of L-2-HG to neonatal rats on redox homeostasis in the cerebellum, which is mostly affected in this disorder. We also determined immunohistochemical landmarks of neuronal viability (NeuN), astrogliosis (S100B and GFAP), microglia activation (Iba1), and myelination (MBP and CNPase) in the cerebral cortex and striatum following L-2-HG administration. Finally, the neuromotor development and cognitive abilities were examined. L-2-HG elicited oxidative stress in the cerebellum 6 h after its injection, which was verified by increased reactive oxygen species production, lipid oxidative damage, and altered antioxidant defenses (decreased concentrations of reduced glutathione and increased glutathione peroxidase and superoxide dismutase activities). L-2-HG also decreased the content of NeuN, MBP, and CNPase, and increased S100B, GFAP, and Iba1 in the cerebral cortex and striatum at postnatal days 15 and 75, implying long-standing neuronal loss, demyelination, astrocyte reactivity, and increased inflammatory response, respectively. Finally, L-2-HG administration caused a delay in neuromotor development and a deficit of cognition in adult animals. Importantly, the antioxidant melatonin prevented L-2-HG-induced deleterious neurochemical, immunohistochemical, and behavioral effects, indicating that oxidative stress may be central to the pathogenesis of brain damage in L-2-HGA.

Changes in neurofilament light chain protein (NEFL) in children and adolescents with Schizophrenia and Bipolar Disorder: Early period neurodegeneration

AIM

Neurofilament light chain protein (NEFL), is defined as a structural protein which exists particularly in axones of neurons and is released to the cerum in consequence of neuroaxonal damage. The aim of this study is to investigate the peripheral cerumNEFLlevels of children and adolescents with early onset schizophrenia and bipolar disorder.

METHOD

In this study, we evaluated serum levels of NEFL in children and adolescents (13-17 years) with schizophrenia, bipolar disorder and healthy control group. The study is conducted with 35 schizophrenia, 38 bipolar disorder manic episode patients and 40 healthy controls.

RESULTS

The median age of the patient and control groups was 16 (IQR- Interquartile Range: 2). There was no statistical difference in median age (p = 0.52) and gender distribution(p = 0.53) between groups. NEFL levels of the patients with schizophrenia were significantly higher than the controls. NEFL levels of the patients with bipolar disorder were significantly higher than the controls. Serum levels of NEFL of the schizophrenia were higher than the bipolar disorder; however, the difference was not statistically significant.

CONCLUSION

In conclusion, serum NEFL level, as a confidential marker of neural damage, is increased in the children and adolescents with bipolar disorder and schizophrenia. This result may indicatea degenerative period in neurons of children and adolescents with schizophrenia or bipolar disorder and may play a role in the pathophisiology of these disorders. This result shows that there is neuronal damage in both diseases, but neuronal damage may be more in schizophrenia.

Anticonvulsant Effects of Royal Jelly in Kainic Acid-Induced Animal Model of Temporal Lobe Epilepsy Through Antioxidant Activity

Temporal lobe epilepsy (TLE) is the most common form of partial and drug-resistant epilepsy, characterized by recurrent seizures originating from temporal lobe structures like the hippocampus. Hippocampal sclerosis and oxidative stress are two important factors in the pathogenesis of TLE that exacerbate epileptic seizures in this form of epilepsy. Recently, royal jelly (RJ) shown to have neuroprotective and antioxidant activities in several neurodegenerative models. Therefore, the aim of the present study was to investigate the pretreatment effect of RJ on epileptic seizures, hippocampal neuronal loss, and oxidative stress in the rat model of kainic acid (KA)-induced TLE. To this aim, 40 male Wistar rats weighing 200-250 g were divided into 4 groups, including control, vehicle, KA, and RJ + KA. Rats received RJ (150 mg/kg/day) for 14 days before induction of TLE with KA. Epileptic behaviors were evaluated according to Racine's scale. Oxidative stress markers including, malondialdehyde (MDA), total oxidant status (TOS) and total antioxidant capacity (TAC) as well as neuronal loss in the CA1 region of the hippocampus (using Nissl staining) were evaluated in all groups. Our findings showed that RJ pretreatment significantly reduced the seizure score and increased the latency to the first seizure. RJ also reduced MDA and TOS while increasing TAC. In addition, RJ reversed neuronal damage in the hippocampal CA1 and CA3 areas. In conclusion, our results suggest that RJ has anticonvulsant and neuroprotective effects in KA induced TLE via its antioxidative properties.

Evaluation of cerebrospinal fluid ubiquitin C-terminal hydrolase-L1, glial fibrillary acidic protein, and neurofilament light protein as novel markers for the diagnosis of neurosyphilis among HIV-negative patients

OBJECTIVES

To evaluate the possibility of using cerebrospinal fluid (CSF) ubiquitin C-terminal hydrolase L1 (UCH-L1), glial fibrillary acidic protein (GFAP), and neurofilament light protein (NF-L) for the diagnosis of neurosyphilis (NS).

METHODS

A cross-sectional study of 576 subjects was conducted at Zhongshan Hospital from January 2021 to August 2022 to evaluate the diagnostic accuracy of CSF UCH-L1, GFAP, and NF-L for NS and analyze their correlations with CSF rapid plasma reagin (RPR), white blood cells (WBCs), and protein.

RESULTS

Patients with NS had higher CSF UCH-L1, GFAP, and NF-L levels than patients with syphilis/non-NS and nonsyphilis. Using a cut-off point of 652.25 pg/ml, 548.89 pg/ml, and 48.38 pg/ml, CSF UCH-L1, GFAP, and NF-L had a sensitivity of 85.11%, 76.60%, and 82.98%, with a specificity of 92.22%, 85.56%, and 91.11%, respectively, for NS diagnosis. Moreover, parallel and serial testing algorithms improved their sensitivity and specificity to 93.62% and 98.89%, respectively. Interestingly, levels between patients with NS who are CSF RPR-positive and -negative did not differ and showed a weak or moderate correlation with WBC and CSF protein in patients with syphilis.

CONCLUSION

CSF UCH-L1, GFAP, and NF-L can be used as novel markers for the diagnosis of NS, independent of CSF RPR, WBC, and proteins.

Influence of furan and lead co-exposure at environmentally relevant concentrations on neurobehavioral performance, redox-regulatory system and apoptotic responses in rats

Furan and lead are contaminants of global concern due to the potential public health threat associated with their exposure. Herein, the neurobehavioral performance, biochemical effects and histological alterations associated with co-exposure to furan (8 mg/kg) and lead acetate at low, environmentally realistic concentrations (1, 10 and 100 µg PbAc/L) for 28 uninterrupted days were investigated in rats. The results demonstrated that locomotor, motor and exploratory deficits associated with separate exposure to furan and lead was exacerbated in the co-exposed rats. Furan and lead co-exposure aggravated the marked decrease in acetylcholinesterase activity and antioxidant status, elevation in oxido-inflammatory stress indices and caspases activation in the cerebrum and cerebellum of exposed rats compared with control. Furan and lead co-exposure worsened neuronal degeneration as verified by histomorphometry and histochemical staining. Collectively, furan and lead acts together to exacerbate neurotoxicity via inhibition of cholinergic system, induction of oxido-inflammatory stress and caspases activation in rats.

Astragalin alleviates cognitive deficits and neuronal damage in SAMP8 mice through upregulating estrogen receptor expression

Senile plaques composed of β-amyloid protein (Aβ) and neurofibrillary tangles (NFTs) composed of intracellular hyper-phosphorylated tau are major causes of cognitive impairment and neuronal damage in Alzheimer disease (AD). Astragalin (AST), a naturally-occurring flavonoid compound, was reported to have neuroprotective effects in the brain, but its effects in AD remain unknown. Herein, the learning and memory deficits were alleviated and neuronal damage in the hippocampus were inhibited after the senescence-accelerated mouse prone 8 (SAMP8) mouse were given AST (5 mg/kg or 10 mg/kg) daily by gavage for 2 months. Furthermore, AST reduced Aβ_1-40 and Aβ_1-42 deposition, decreased β-carboxyl-terminal fragment (β-CTF) protein level and tau hyper-phosphorylation, but increased α-CTF protein level and glycogen synthase kinase-3beta (GSK-3β) phosphorylation in hippocampus of SAMP8 mice. Meanwhile, the effects of AST on AD were also explored in vitro by treating primary neurons with amyloid-β1-42 oligomers (Aβ_1-42O). Consistently, AST also alleviated amyloid-β1-42 oligomers (Aβ_1-42O)-induced neuronal damage, amyloid plaques, and tau phosphorylation in vitro model. Of note, estrogen receptor (ER)α and ERβ expression in the hippocampus of SAMP8 mice and Aβ_1-42O-treated neurons was significantly decreased but their levels were increased by AST. Moreover, in vivo and in vitro experiments revealed that ER antagonist, Fulvestrant, reversed the effects caused by AST. Altogether, our investigation indicates that AST may ameliorate cognitive deficits and AD-type pathologies in SAMP8 mice and Aβ_1-42O-treated neurons through upregulating ERα and ERβ expression. Our findings indicate the value of AST as a potential reagent for AD treatment.

Drp1 activates ROS/HIF-1α/EZH2 and triggers mitochondrial fragmentation to deteriorate hypercalcemia-associated neuronal injury in mouse model of chronic kidney disease

Background

Chronic kidney disease (CKD), characterized as renal dysfunction, is regarded as a major public health problem which carries a high risk of cardiovascular diseases. The purpose of this study is to evaluate the functional significance of Drp1 in hypercalcemia-associated neuronal damage following CKD and the associated mechanism.

Methods

Initially, the CKD mouse models were established. Next, RT-qPCR and Western blot analysis were performed to measure expression of Fis1 and Drp1 in CKD. Chromatin immunoprecipitation (ChIP) assay and dual-luciferase reporter gene assay were utilized to explore the relationship among Drp1, HIF-1α, EZH2, and ROS with primary cortical neurons isolated from neonatal mice. Next, CKD mice were subjected to calcitonin treatment or manipulation with adenovirus expressing sh-Drp1, so as to explore the effects of Drp1 on hypercalcemia-induced neuronal injury in CKD. TUNEL assay and immunofluorescence staining were performed to detect apoptosis and NeuN-positive cells (neurons) in prefrontal cortical tissues of CKD mice.

Results

It was found that hypercalcemia could induce neuronal injury in CKD mice. An increase of Fis1 and Drp1 expression in cerebral cortex of CKD mice correlated with mitochondrial fragmentation. Calcitonin suppressed Drp1/Fis1-mediated mitochondrial fragmentation to attenuate hypercalcemia-induced neuronal injury after CKD. Additionally, Drp1 could increase EZH2 expression through the binding of HIF-1α to EZH2 promoter via elevating ROS generation. Furthermore, Drp1 knockdown inhibited hypercalcemia-induced neuronal injury in CKD while overexpression of EZH2 could reverse this effect in vivo.

Conclusion

Taken together, the key findings of the current study demonstrate the promotive role of Drp1 in mitochondrial fragmentation which contributes to hypercalcemia-induced neuronal injury in CKD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02542-7.

GPR120 modulates epileptic seizure and neuroinflammation mediated by NLRP3 inflammasome

Background

The complex pathophysiology of epilepsy hampers the development of effective treatments. Although more than ten kinds of anti-seizures drugs (ASDs) have good effects on seizure control worldwide, about 30% of patients still display pharmacoresistance against ASDs. Neuroinflammation seems to play a crucial role in disease progression. G protein-coupled receptor 120 (GPR120) has been shown to negatively regulate inflammation and apoptosis. However, the role of GPR120 in epilepsy remains unclear. In this study, we aimed to explore the mechanism of GPR120 in epilepsy.

Methods

Male adult C57BL/6 mice were intracranially injected with kainic acid (KA) to establish epilepsy model, and the adeno associated virus (AAV) was administered intracranially at 3 weeks before KA injection. VX765 was administered by intragastric administration at 30 min before KA induced and an equal dose administrated twice a day (10 a.m. and 4 p.m.) lasting 7 days until the mice were killed. Western blot analysis, immunofluorescence staining, video monitoring of seizure, LFP recording, Nissl staining were performed.

Results

GPR120 was increased in both the hippocampus and cortex in the KA-induced model with temporal lobe epilepsy (TLE), and both were most highly expressed at 7 days after KA injection. Overexpression of GPR120 significantly alleviated epileptic activity, reduced neuronal death after status epilepticus (SE), downregulated the expression of IL-1β, IL-6, IL-18, and pyrin domain-containing protein 3 (NLRP3) inflammasome, whereas knockdown GPR120 showed the opposite effect. The effects of GPR120 knockdown were reversed by VX765 inhibition cysteinyl aspartate specific proteinase-1 (Caspase-1).

Conclusion

GPR120 modulates epileptic seizure activity and affects neuronal survival in KA-induced mouse model of temporal lobe epilepsy. Furthermore, GPR120 regulated neuroinflammation in epileptic animals through NLRP3/Caspase-1/IL-1β signaling pathway.

Robust chronic convulsive seizures, high frequency oscillations, and human seizure onset patterns in an intrahippocampal kainic acid model in mice

Intrahippocampal kainic acid (IHKA) has been widely implemented to simulate temporal lobe epilepsy (TLE), but evidence of robust seizures is usually limited. To resolve this problem, we slightly modified previous methods and show robust seizures are common and frequent in both male and female mice. We employed continuous wideband video-EEG monitoring from 4 recording sites to best demonstrate the seizures. We found many more convulsive seizures than most studies have reported. Mortality was low. Analysis of convulsive seizures at 2-4 and 10-12 wks post-IHKA showed a robust frequency (2-4 per day on average) and duration (typically 20-30 s) at each time. Comparison of the two timepoints showed that seizure burden became more severe in approximately 50% of the animals. We show that almost all convulsive seizures could be characterized as either low-voltage fast or hypersynchronous onset seizures, which has not been reported in a mouse model of epilepsy and is important because these seizure types are found in humans. In addition, we report that high frequency oscillations (>250 Hz) occur, resembling findings from IHKA in rats and TLE patients. Pathology in the hippocampus at the site of IHKA injection was similar to mesial temporal lobe sclerosis and reduced contralaterally. In summary, our methods produce a model of TLE in mice with robust convulsive seizures, and there is variable progression. HFOs are robust also, and seizures have onset patterns and pathology like human TLE. SIGNIFICANCE: Although the IHKA model has been widely used in mice for epilepsy research, there is variation in outcomes, with many studies showing few robust seizures long-term, especially convulsive seizures. We present an implementation of the IHKA model with frequent convulsive seizures that are robust, meaning they are >10 s and associated with complex high frequency rhythmic activity recorded from 2 hippocampal and 2 cortical sites. Seizure onset patterns usually matched the low-voltage fast and hypersynchronous seizures in TLE. Importantly, there is low mortality, and both sexes can be used. We believe our results will advance the ability to use the IHKA model of TLE in mice. The results also have important implications for our understanding of HFOs, progression, and other topics of broad interest to the epilepsy research community. Finally, the results have implications for preclinical drug screening because seizure frequency increased in approximately half of the mice after a 6 wk interval, suggesting that the typical 2 wk period for monitoring seizure frequency is insufficient.

The role of Rho/ROCK in epileptic seizure-related neuronal damage

Epilepsy is one of the most severe neurological disorders characterized by spontaneous recurrent seizures. Although more than two-thirds of patients can be cured with anti-epileptic drugs (AEDs), the rest one-third of epilepsy patients are resistant to AEDs. A series of studies have demonstrated Rho/Rho-associated kinase (ROCK) pathway might be involved in the pathogenesis of epilepsy in the recent twenty years. Several related pathway inhibitors of Rho/ROCK have been used in the treatment of epilepsy. We searched PubMed from Jan 1, 2000 to Dec 31, 2020, using the terms "epilepsy AND Rho AND ROCK" and "seizure AND Rho AND ROCK". We selected articles that characterized Rho/ROCK in animal models of epilepsy and patients. We then chose the most relevant research studies including in-vitro, in-vivo and clinical trials. The expression of Rho/ROCK could be a potential non-invasive biomarker to apply in treatment for patients with epilepsy. RhoA and ROCK show significant upregulation in the acute and chronic stage of epilepsy. ROCK inhibitors can reduce the epilepsy, epileptic seizure-related neuronal death and comorbidities. These findings demonstrate the novel development for diagnosis and treatment for patients with epilepsy. Rho/ROCK signaling pathway inhibitors may show more promising effects in epilepsy and related neurological diseases.

ADSC-Exosomes Alleviate MTX-induced Rat Neuronal Damage by Activating Nrf2-ARE Pathway

The aim of this study was to analyze the efficacy and underlying mechanism of adipose-derived mesenchymal stem cell exosome (ADSC-exosomes)-mediated protection on methotrexate (MTX)-induced neuronal damage. We established a H₂O₂-induced oxidative stress model in vitro, as well as an MTX-induced neuronal damage rat model in vivo. We analyzed the effects of ADSC-exosomes on neuronal damage and Nrf2-ARE signaling pathway in rats and related mechanisms. The morphological and functional recovery of rat hippocampal neurons by ADSC-exosomes was examined by Nissl staining and modified neurological severity score (mNSS) score. The activation of Nrf2-ARE pathway effectively inhibited H₂O₂-induced oxidative stress. ADSC-exosomes treatment restored the activity of hippocampal neuronal cells, reduced ROS production, and inhibited hippocampal neuronal cells apoptosis. In in vivo experiments, ADSC-exosomes ameliorates MTX-induced hippocampal neuron damage by triggering Nrf2-ARE pathway, decreasing IL-6, IFN-, and TNF-a levels and TUNEL positive cells in hippocampus, and repairing hippocampal neuronal cell damage. ADSC-exosomes ameliorated MTX-induced neuronal damage and suppressed oxidative stress induced by neuronal damage through the activation of Nrf2-ARE signaling pathway.

Glutamatergic transmission associated with locomotion-related neurotoxicity to lindane over generations in Caenorhabditis elegans

Organochlorine pesticide lindane in the environment and biota results in the potential risks on ecosystem and human health. Lindane can adversely affect the locomotion and nervous system, yet the potential neurotoxicity of lindane over generations remains uncertain. In this study, the neurotoxicity and underlying mechanisms in Caenorhabditis elegans (C. elegans) were investigated after parental (P0) exposure to lindane at environmentally relevant concentrations over generations. Exposure to lindane at concentrations of 10-100 ng/L significantly decreased body bends and head thrashes in P0 generation. Significant decrease of fluorescence labeled different neurotransmitters, and clear morphological changes by exposure to lindane at 10-100 ng/L suggested that lindane could induce the neuronal damage in C. elegans. During the transgenerational process, decreased locomotive behaviors were also observed in F1-F3 generations, and head thrashes returned to normal levels in F4 generation. Moreover, lindane exposure down-regulated the expression of dat-1, dop-1, glr-1 and mod-1genes, while up-regulated unc-30 gene in P0 generation, which recovered to normal levels in F4 generation. Interestingly, eat-4 continued to be regulated from inhibition to stimulation in P0-F4 generations, suggesting that glutamatergic transmission may more contribute to the neurotoxicity of lindane over generations.

Arsenic Induces Differential Neurotoxicity in Male, Female, and E2-Deficient Females: Comparative Effects on Hippocampal Neurons and Cognition in Adult Rats

We earlier reported that arsenic induced hippocampal neuronal loss, causing cognitive dysfunctions in male rats. This neuronal damage mechanism involved an altered bone morphogenetic protein (BMP2)/Smad and brain-derived neurotrophic factor (BDNF)/TrkB signaling. Susceptibility to toxicants is often sex-dependent, and hence we studied the comparative effects of arsenic in adult male and female rats. We observed that a lower dose of arsenic reduced learning-memory ability, examined through passive avoidance and Y-maze tests, in male but not female rats. Again, male rats exhibited greater learning-memory loss at a higher dose of arsenic. Supporting this, arsenic-treated male rats demonstrated larger reduction in the hippocampal NeuN and %-surviving neurons, together with increased apoptosis and altered BMP2/Smad and BDNF/TrkB pathways compared to their female counterparts. Since the primary female hormone, estrogen (E2), regulates normal brain functions, we next probed whether endogenous E2 levels in females offered resistance against arsenic-induced neurotoxicity. We used ovariectomized (OVX) rat as the model for E2 deficiency. We primarily identified that OVX itself induced hippocampal neuronal damage and cognitive decline, involving an increased BMP2/Smad and reduced BDNF/TrkB. Further, these effects appeared greater in arsenic + OVX compared to arsenic + sham (ovary intact) or OVX rats alone. The OVX-induced adverse effects were significantly reduced by E2 treatment. Overall, our study suggests that adult males could be more susceptible than females to arsenic-induced neurotoxicity. It also indicates that endogenous E2 regulates hippocampal BMP and BDNF signaling and restrains arsenic-induced neuronal dysfunctions in females, which may be inhibited in E2-deficient conditions, such as menopause or ovarian failure.

Neuroprotective effects of Lippia javanica (Burm.F.) Spreng. Herbal tea infusion on Lead-induced oxidative brain damage in Wistar rats

Background

Though Lippia javanica (Burm.f.) Spreng antioxidant activity has been demonstrated, its effect in protecting the brain from lead (Pb)-induced oxidative damage is unknown. This study investigated the effect of L. javanica against Pb-induced oxidative stress, inflammation, apoptosis and acetylcholinesterase activity in rat’s brain.

Methods

L. javanica herbal tea infusion was prepared, its phytochemical constituent was revealed by liquid chromatography-Mass spectrometer (LC-MS) and was administered simultaneously with Pb. Four groups of male Wistar rats (n = 5/group) were used: control received distilled water; Pb-acetate group received 50 mg Pb/ Kg bodyweight (bw), treatment group received 50 mg Pb/ Kg Pb-acetate + 5 ml/kg bw L. javanica and L. javanica group received 5 ml/Kg bw of L. javanica tea infusion only. After 6 weeks of treatment, oxidative status, acetylcholinesterase activity, inflammation and apoptosis was assessed in brain tissue which was also histologically examined.

Results

Mean brain and heart weight was reduced (p < 0.05) while liver and spleen weights were increased (p < 0.05) in Pb exposed animals but were prevented by L. juvanica treatment. Treatment with L. javanica increased (p < 0.05) overall brain antioxidant status (glutathione and superoxide dismutase activities) and reduced lipid peroxidation (p < 0.05) compared to the Pb exposed animals. Pro-inflammatory cytokine tumour necrotic factor-alpha, pro-apoptosis Bax protein and anticholinesterase activity were reduced (p < 0.05) in Pb-L. javanica treated animals compared to the Pb exposed group. Histological examination confirmed neuroprotective effects of L. javanica as evidenced by reduced apoptosis/necrosis and inflammation-induced vacuolization and oedema in the hippocampus. The L. javanica treatment alone had no detrimental effects to the rats. LC-MS analysis revealed L. javanica to be rich in phenolics.

Conclusions

This study demonstrated that L. javanica, rich in phenolics was effective in reducing Pb-induced brain oxidative stress, inflammation, apoptosis, acetylcholinesterase activity and neuronal damage.

CCR5 antagonist reduces HIV-induced amyloidogenesis, tau pathology, neurodegeneration, and blood-brain barrier alterations in HIV-infected hu-PBL-NSG mice

BACKGROUND

Neurocognitive impairment is present in 50% of HIV-infected individuals and is often associated with Alzheimer's Disease (AD)-like brain pathologies, including increased amyloid-beta (Aβ) and Tau hyperphosphorylation. Here, we aimed to determine whether HIV-1 infection causes AD-like pathologies in an HIV/AIDS humanized mouse model, and whether the CCR5 antagonist maraviroc alters HIV-induced pathologies.

METHODS

NOD/scid-IL-2Rγcnull mice engrafted with human blood leukocytes were infected with HIV-1, left untreated or treated with maraviroc (120 mg/kg twice/day). Human cells in animal's blood were quantified weekly by flow cytometry. Animals were sacrificed at week-3 post-infection; blood and tissues viral loads were quantified using p24 antigen ELISA, RNAscope, and qPCR. Human (HLA-DR+) cells, Aβ-42, phospho-Tau, neuronal markers (MAP 2, NeuN, neurofilament-L), gamma-secretase activating protein (GSAP), and blood-brain barrier (BBB) tight junction (TJ) proteins expression and transcription were quantified in brain tissues by immunohistochemistry, immunofluorescence, immunoblotting, and qPCR. Plasma Aβ-42, Aβ-42 cellular uptake, release and transendothelial transport were quantified by ELISA.

RESULTS

HIV-1 significantly decreased human (h)CD4+ T-cells and hCD4/hCD8 ratios; decreased the expression of BBB TJ proteins claudin-5, ZO-1, ZO-2; and increased HLA-DR+ cells in brain tissues. Significantly, HIV-infected animals showed increased plasma and brain Aβ-42 and phospho-Tau (threonine181, threonine231, serine396, serine199), associated with transcriptional upregulation of GSAP, an enzyme that catalyzes Aβ formation, and loss of MAP 2, NeuN, and neurofilament-L. Maraviroc treatment significantly reduced blood and brain viral loads, prevented HIV-induced loss of neuronal markers and TJ proteins; decreased HLA-DR+ cells infiltration in brain tissues, significantly reduced HIV-induced increase in Aβ-42, GSAP, and phospho-Tau. Maraviroc also reduced Aβ retention and increased Aβ release in human macrophages; decreased the receptor for advanced glycation end products (RAGE) and increased low-density lipoprotein receptor-related protein-1 (LRP1) expression in human brain endothelial cells. Maraviroc induced Aβ transendothelial transport, which was blocked by LRP1 antagonist but not RAGE antagonist.

CONCLUSIONS

Maraviroc significantly reduced HIV-induced amyloidogenesis, GSAP, phospho-Tau, neurodegeneration, BBB alterations, and leukocytes infiltration into the CNS. Maraviroc increased cellular Aβ efflux and transendothelial Aβ transport via LRP1 pathways. Thus, therapeutically targeting CCR5 could reduce viremia, preserve the BBB and neurons, increased brain Aβ efflux, and reduce AD-like neuropathologies.

Effects of lanthanum nitrate on behavioral disorder, neuronal damage and gene expression in different developmental stages of Caenorhabditis elegans

Rare earth elements (REEs) are widely used in the industry, agriculture, biomedicine, aerospace, etc, and have been shown to pose toxic effects on animals, as such, studies focusing on their biomedical properties are gaining wide attention. However, environmental and population health risks of REEs are still not very clear. Also, the REEs damage to the nervous system and related molecular mechanisms needs further research. In this study, the L1 and L4 stages of the model organism Caenorhabditis elegans were used to evaluate the effects and possible neurotoxic mechanism of lanthanum(III) nitrate hexahydrate (La(NO₃)₃·6H₂O). For the L1 and L4 stage worms, the 48-h median lethal concentrations (LC₅₀s) of La(NO₃)₃·6H₂O were 93.163 and 648.0 mg/L respectively. Our results show that La(NO₃)₃·6H₂O induces growth inhibition and defects in behavior such as body length, body width, body bending frequency, head thrashing frequency and pharyngeal pumping frequency at the L1 and L4 stages in C. elegans. The L1 stage is more sensitive to the toxicity of lanthanum than the L4 stage worms. Using transgenic strains (BZ555, EG1285 and NL5901), we found that La(NO₃)₃·6H₂O caused the loss or break of soma and dendrite neurons in L1 and L4 stages; and α-synuclein aggregation in L1 stage, indicating that Lanthanum can cause toxic damage to dopaminergic and GABAergic neurons. Mechanistically, La(NO₃)₃·6H₂O exposure inhibited or activated the neurotransmitter transporters and receptors (glutamate, serotonin and dopamine) in C. elegans, which regulate behavior and movement functions. Furthermore, significant increase in the production of reactive oxygen species (ROS) was found in the L4 stage C. elegans exposed to La(NO₃)₃·6H₂O. Altogether, our data show that exposure to lanthanum can cause neuronal toxic damage and behavioral defects in C. elegans, and provide basic information for understanding the neurotoxic effect mechanism and environmental health risks of rare earth elements.

Core cerebrospinal fluid biomarker profile in anti-LGI1 encephalitis

OBJECTIVE

To compare CSF biomarkers' levels in patients suffering from anti-Leucine-rich Glioma-Inactivated 1 (LGI1) encephalitis to neurodegenerative [Alzheimer's disease (AD), Creutzfeldt-Jakob's disease (CJD)] and primary psychiatric (PSY) disorders.

METHODS

Patients with LGI1 encephalitis were retrospectively selected from the French Reference Centre database between 2010 and 2019 and enrolled if CSF was available for biomarkers analysis including total tau (T-tau), phosphorylated tau (P-tau), amyloid-beta Aβ1-42, and neurofilaments light chains (Nf L). Samples sent for biomarker determination as part of routine practice, and formally diagnosed as AD, CJD, and PSY, were used as comparators.

RESULTS

Twenty-four patients with LGI1 encephalitis were compared to 39 AD, 20 CJD and 20 PSY. No significant difference was observed in T-tau, P-tau, and Aβ1-42 levels between LGI1 encephalitis and PSY patients. T-Tau and P-Tau levels were significantly lower in LGI1 encephalitis (231 and 43 ng/L) than in AD (621 and 90 ng/L, p < 0.001) and CJD patients (4327 and 55 ng/L, p < 0.001 and p < 0.01). Nf L concentrations of LGI1 encephalitis (2039 ng/L) were similar to AD (2,765 ng/L) and significantly higher compared to PSY (1223 ng/L, p < 0.005), but significantly lower than those of CJD (13,457 ng/L, p < 0.001). Higher levels of Nf L were observed in LGI1 encephalitis presenting with epilepsy (3855 ng/L) compared to LGI1 without epilepsy (1490 ng/L, p = 0.02). No correlation between CSF biomarkers' levels and clinical outcome could be drawn.

CONCLUSION

LGI encephalitis patients showed higher Nf L levels than PSY, comparable to AD, and even higher when presenting epilepsy suggesting axonal or synaptic damage linked to epileptic seizures.

Tripartite-motif protein 21 knockdown extenuates LPS-triggered neurotoxicity by inhibiting microglial M1 polarization via suppressing NF-κB-mediated NLRP3 inflammasome activation

Tripartite motif-containing 21 (TRIM21) has been confirmed to mediate the production of inflammatory mediators via NF-κB signaling. However, the function of TRIM21 in microglia-mediated neuroinflammation remains unclear. This study aimed to explore the effect of TRIM21 on LPS-activated BV2 microglia and its underlying mechanism. BV2 cells exposed to lipopolysaccharide (LPS) were used to simulated neuroinflammation in vitro. Loss-of-function and gain-of-function of TRIM21 in BV2 cells were used to assess the effect of TRIM21 on LPS-induced neuroinflammation. BV2 microglia and HT22 cells co-culture system were used to investigate whether TRIM21 regulated neuronal inflammation-mediated neuronal death. TRIM21 knockdown triggered the polarization of BV2 cells from M1 to M2 phenotype. Knockdown of TRIM21 reduced the secretion of TNF-α, IL-6, and IL-1β, while increased the content of IL-4 in LPS-treated cells. Knockdown of TRIM21 inhibited the expression of p65 and the binding activity of NF-κB-DNA. Additionally, TRIM21 siRNA eliminated the increase in NLRP3 and cleaved caspase-1 proteins expression and caspase-1 activity induced by LPS. TRIM21 knockdown could resist cytotoxicity induced by activated microglia, including increasing the viability of co-cultured HT22 cells and reducing the emancipation of LDH. Moreover, the increased apoptosis and caspase-3 activity of HT22 neurons induced by activated BV2 cells were blocked by TRIM21 siRNA. Blocking of NF-κB abolished the effect of TRIM21 in promoting the expression of M1 phenotype marker genes. Similarly, the blockade of NF-κB pathway eliminated the promotion of TRIM21 on neurotoxicity induced by neuroinflammation. TRIM21 knockdown suppressed the M1 phenotype polarization of microglia and neuroinflammation-mediated neuronal damage via NF-κB/NLRP3 inflammasome pathway, which suggested that TRIM21 might be a potential therapeutic target for the therapy of central nervous system diseases.

Protective effects of lamotrigine and vitamin B12 on pentylenetetrazole-induced epileptogenesis in rats

Epileptogenesis is a process that includes molecular and cellular events that foster the establishment of hyperexcitable neuronal networks in the brain. Pentylenetetrazole (PTZ)-induced kindling model in rodents has added new information to the knowledge about the pathogenesis of epilepsy and potential targets of novel antiepileptic agents. Evidence from animal and human studies suggests that oxidative and inflammatory events may play important roles in the initiation and maintaining seizure activities. Vitamin B12 has beneficial effects on the nervous system and presents pleiotropic effects with antioxidant and anti-inflammatory aspects. In the present study, we aimed to test the hypothesis that vitamin B12 and their combination with lamotrigine prevents behavioral deficits, hippocampal damage, oxidation, and proinflammatory state during epileptogenesis. Male rats were subjected to PTZ-induced epileptogenesis and pretreated with vitamin B12 (50 µg/kg) or Lamotrigine (LTG) (25 mg/kg) or B12 (50 µg/kg) + LTG (25 mg/kg). Vitamin B12 and its combination with LTG suppressed epileptogenesis and improved the performance of rats in the passive avoidance test. In addition, Vitamin B12 and its combination with LTG decreased levels of total oxidative status (TOS), oxidative stress index (OSI), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and increased total antioxidant status (TAS) levels in the hippocampus and cerebral cortex. Furthermore, it reduced hippocampal neuronal damage. Current findings support the beneficial actions of vitamin B12 due to its antioxidative and anti-inflammatory properties during the course of disease.

Neuroprotection of Heme Oxygenase-2 in Mice AfterIntracerebral Hemorrhage

There are few effective preventive or therapeutic strategies to mitigate the effects of catastrophic intracerebral hemorrhage (ICH) in humans. Heme oxygenase is the rate-limiting enzyme in heme metabolism; heme oxygenase-2 (HO-2) is a constitutively expressed heme oxygenase. We explored the involvement of HO-2 in a collagenase-induced mouse model of ICH in C57BL/6 wild-type and HO-2 knockout mice. We assessed oxidative stress injury, blood-brain barrier permeability, neuronal damage, late-stage angiogenesis, and hematoma clearance using immunofluorescence, Western blot, MRI, and special staining methods. Our results show that HO-2 reduces brain injury volume and brain edema, alleviates cytotoxic injury, affects vascular function in the early stage of ICH, and improves hematoma absorbance and angiogenesis in the late stage of ICH in this model. Thus, we found that HO-2 has a protective effect on brain injury after ICH.

Ovarian hormones prevent methamphetamine-induced anxiety-related behaviors and neuronal damage in ovariectomized rats

Methamphetamine (METH) may cause long‒lasting neurotoxic effects and cognitive impairment. On the other hand, the ovarian hormones estrogen and progesterone have neuroprotective effects. In the current study, we aimed to examine the effects of estrogen and progesterone on anxiety‒like behavior and neuronal damage in METH‒exposed ovariectomized (OVX) rats. Three weeks after ovariectomy, the animals received estrogen (1 mg/kg, i.p.), or progesterone (8 mg/kg, i.p.), or estrogen plus progesterone (with the same doses), or vehicle during 7 consecutive days (days 22-28). On day 28, OVX rats were exposed to a single‒day METH regimen (6 mg/kg, four s.c. Injections, with 2 h interval) 30 min after the hormone treatment. The next day (on day 29), the animals were assessed for anxiety‒related behaviors using the open field and elevated plus‒maze tasks. The animals were then sacrificed and brain water content, cell apoptosis and expression of IL-1β were evaluated. The findings showed that treatment with estrogen or progesterone alone in METH‒exposed rats significantly improved hyperthermia, anxiety‒like behavior, neuronal damage, and inflammation in the CA1 area. Also, treatment with estrogen plus progesterone improved hyperthermia and brain edema. Taken together, the findings suggest that treatment with ovarian hormones can partially prevent hyperthermia and anxiety‒related behaviors induced by METH in OVX rats, which could be accompanied by their neuroprotective effects in the hippocampus.

Neuroinflammation, neuronal damage or cognitive impairment associated with mechanical ventilation: A systematic review of evidence from animal studies

PURPOSE

Long-term cognitive impairment is a complication of critical illness survivors. Beside its lifesaving role, mechanical ventilation has potential complications. The aim of this study is to systematically review the evidence collected in animal studies that correlate mechanical ventilation with neuroinflammation, neuronal damage and cognitive impairment.

METHODS

We searched MEDLINE and EMBASE databases for studies published from inception until August 31st, 2020, that enrolled mechanically ventilated animals and reported on neuroinflammation or neuronal damage markers changes or cognitive-behavioural impairment.

RESULTS

Of 5583 studies, 11 met inclusion criteria. Mice, rats, pigs were used. Impact of MV: 4 out of 7 studies reported higher neuroinflammation markers in MV-treated animals and 3 studies reported no differences; 7 out of 8 studies reported a higher neuronal damage and 1 reported no differences; 2 out of 2 studies reported cognitive decline up to 3 days after MV. Higher Tidal volumes are associated with higher changes in brain or serum markers.

CONCLUSION

Preclinical evidence suggests that MV induces neuroinflammation, neuronal damage and cognitive impairment and these are worsened if sub-optimal MV settings are applied. Future studies, with appropriate methodology, are necessary to evaluate for serum monitoring strategies.

TRIAL REGISTRATION NUMBER

CRD42019148935.

The effects of salmon calcitonin on epileptic seizures, epileptogenesis, and postseizure hippocampal neuronal damage in pentylenetetrazole-induced epilepsy model in rats

Epilepsy is one of the most common neurological disorders that severely affect the life quality of many people worldwide. Excitatory-inhibitory mechanisms, oxidative stress, and also inflammation systems have been implicated in the pathogenesis of epilepsy. Recent studies have shown that salmon calcitonin (sCT) has positive effects on the nervous system. However, its relation with epilepsy is still unclear. This study aimed to investigate the effect of sCT on epileptic seizures, epileptogenesis, and postseizure hippocampal neuronal damage in pentylenetetrazole (PTZ)-induced epilepsy model in rats. The study was performed in two steps. In the first step, the effect of sCT on epileptic seizures was evaluated by using electroencephalography (EEG) in fully kindled rats. In the second step, the effect of sCT on epileptogenesis was evaluated by using the kindling process. Glutamate and gamma-aminobutyric acid (GABA), thiobarbituric acid reactive substance (TBARS), superoxide dismutase (SOD), catalase (CAT), tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1 β), and interleukin 6 (IL-6) were measured in the second group in the brain and serum. Hippocampal regions were stained with hematoxylin-eosin and toluidine blue to evaluate hippocampal neuronal damage histopathologically. Salmon calcitonin showed an antiepileptic effect in fully kindled rats and also prevented the development of epileptogenesis in the kindling process. Besides, sCT decreased glutamate and increased GABA levels. Furthermore, it reduced TBARS levels and increased SOD and CAT levels. On the other hand, it decreased TNF-α levels, IL-1 β levels, and IL-6 levels. Histopathologically, sCT decreased neuronal damage in all hippocampal regions. Our findings are the first preclinical report to show the positive effect of sCT on epileptic seizures and epileptogenesis. Further investigation is required to answer the questions raised about the probable mechanisms involved.

Inhibition of the BCL6/miR-31/PKD1 axis attenuates oxidative stress-induced neuronal damage

Ischemic stroke (IS) is one of the most common cerebrovascular diseases worldwide. The aberrant expression of BCL6 has been previously implicated in the pathogenesis of IS. Meanwhile, miR-31 is known as a target of BCL6, and has also been suggested to diminish cell damage by suppressing the PKD1 expression. Expanding on this relationship, the current study set out to investigate whether BCL6 participates in ischemic stroke by targeting PKD1. Firstly, IS models were established in vitro and in vivo. TUNEL staining and MTT assay were performed to examine the apoptosis and cell survival. In addition, qRT-PCR and Western blot analysis were applied to examine the expression patterns of the BCL6/miR-31/PKD1 axis and its downstream pathway. Bioinformatics analysis was used to predict the target of miR-31. It was found that BCL6 over-expression promoted ODG-induced increase of apoptosis and decreased the cell survival and miR-31 expression levels, whereas the opposite effects were noted in vitro and in vivo models of IS that were treated with shBCL6. Furthermore, miR-31 down-regulation blocked the effect of BCL6 on ODG-induced cell injury. It was also verified that miR-31 directly-targets PKD1. Also, OGD induced the PKD1 expression and activation of the JAK2/STAT3 pathway, while down-regulation of PKD1 inhibited the OGD-induced cell injury and JAK2/STAT3 pathway activation. Lastly, down-regulation of BCL6 in brain brought about a significant reduction in the size of cerebral infarction and oxidative stress levels in IS mice. Collectively, our findings suggest that inhibition of BCL6 may attenuate oxidative stress-induced neuronal damage by targeting the miR-31/PKD1 axis.

Oxygen exposure in early life activates NLRP3 inflammasome in mouse brain

Despite widely known detrimental effects on the developing brain, supplemental oxygen is still irreplaceable in the management of newborn infants with respiratory distress. Identifying downstream mechanisms underlying oxygen toxicity is a key step for development of new neuroprotective strategies. Main purpose of this study is to investigate whether NLRP3 inflammasome activation has a role in the pathogenesis of hyperoxia-induced preterm brain injury. C57BL6 pups were randomly divided into either a hyperoxia group (exposed to 90 % oxygen from birth until postnatal day 7) or control group (maintained in room air; 21 % O₂). At postnatal day 7, all animals were sacrificed. Immunohistochemical examination revealed that hyperoxic exposure for seven days resulted in a global increase in NLRP3 and IL-1β immunopositive cells in neonatal mouse brain (p ≤ 0.001). There was a significant rise in Caspase-1 positive cell count in prefrontal and parietal area in the hyperoxia group when compared with controls (p ≤ 0.001). Western blot analysis of brain tissues showed elevated NLRP3, IL-1β and Caspase-1 protein levels in the hyperoxia group when compared with controls (p ≤ 0.001). To the best of our knowledge, this is the first study that investigates an association between hyperoxia and establishment of NLRP3 inflammasome in preterm brain.

Evaluation of neurofilament light chain in the cerebrospinal fluid and blood as a biomarker for neuronal damage in experimental pneumococcal meningitis

Background

Pneumococcal meningitis (PM) remains a global public health concern and affects all age groups. If acquired during infancy or childhood, permanent neurofunctional deficits including cognitive impairment, cerebral palsy, and secondary epilepsy are typical sequelae of neuronal injury. Determination of patients at risk for the development of brain injury and subsequent neurofunctional sequelae could help to identify patients for focused management. Neurofilament light chain (NfL) is an axonal cytoskeletal protein released upon neuronal injury into the cerebrospinal fluid (CSF) and blood. As little is known about the course of neurofilament release in the course of PM, we measured CSF and serum NfL levels longitudinally in experimental PM (ePM).

Methods

Eleven-day-old infant Wistar rats were infected intracisternally with Streptococcus pneumoniae and treated with ceftriaxone. At 18 and 42 h post-infection (hpi), the blood and CSF were sampled for NfL measurements by a single molecule array technology. Inflammatory cytokines and MMP-9 in CSF were quantified by magnetic bead multiplex assay (Luminex®) and by gel zymography, respectively.

Results

In ePM, CSF and serum NfL levels started to increase at 18 hpi and were 26- and 3.5-fold increased, respectively, compared to mock-infected animals at 42 hpi (p < 0.0001). CSF and serum NfL correlated at 18 hpi (p < 0.05, r = 0.4716) and 42 hpi (p < 0.0001, r = 0.8179). Both CSF and serum NfL at 42 hpi strongly correlated with CSF levels of IL-1β, TNF-α, and IL-6 and of MMP-9 depending on their individual kinetics.

Conclusion

Current results demonstrate that during the peak inflammatory phase of ePM, NfL levels in CSF and serum are the highest among CNS disease models studied so far. Given the strong correlation of CSF versus serum NfL, and its CNS-specific signal character, longitudinal measurements to monitor the course of PM could be performed based on blood sample tests, i.e., without the need of repetitive spinal taps. We conclude that NfL in the serum should be evaluated as a biomarker in PM.

Biomarkers of neuronal damage in saturation diving-a controlled observational study

Purpose

A prospective and controlled observational study was performed to determine if the central nervous system injury markers glial fibrillary acidic protein (GFAp), neurofilament light (NfL) and tau concentrations changed in response to a saturation dive.

Methods

The intervention group consisted of 14 submariners compressed to 401 kPa in a dry hyperbaric chamber. They remained pressurized for 36 h and were then decompressed over 70 h. A control group of 12 individuals was used. Blood samples were obtained from both groups before, during and after hyperbaric exposure, and from the intervention group after a further 25–26 h.

Results

There were no statistically significant changes in the concentrations of GFAp, NfL and tau in the intervention group. During hyperbaric exposure, GFAp decreased in the control group (mean/median − 15.1/ − 8.9 pg·mL⁻¹, p < 0.01) and there was a significant difference in absolute change of GFAp and NfL between the groups (17.7 pg·mL⁻¹, p = 0.02 and 2.34 pg·mL⁻¹, p = 0.02, respectively). Albumin decreased in the control group (mean/median − 2.74 g/L/ − 0.95 g/L, p = 0.02), but there was no statistically significant difference in albumin levels between the groups. In the intervention group, haematocrit and mean haemoglobin values were slightly increased after hyperbaric exposure (mean/median 2.3%/1.5%, p = 0.02 and 4.9 g/L, p = 0.06, respectively).

Conclusion

Hyperbaric exposure to 401 kPa for 36 h was not associated with significant increases in GFAp, NfL or tau concentrations. Albumin levels, changes in hydration or diurnal variation were unlikely to have confounded the results. Saturation exposure to 401 kPa seems to be a procedure not harmful to the central nervous system.

Trial registration

ClinicalTrials.gov NCT03192930.

Research progress and treatment strategies for anesthetic neurotoxicity

Every year, a large number of infants and young children worldwide are administered general anesthesia. Whether general anesthesia adversely affects the intellectual development and cognitive function of children at a later date remains controversial. Many animal experiments have shown that general anesthetics can cause nerve damage during development, affect synaptic plasticity, and induce apoptosis, and finally affect learning and memory function in adulthood. The neurotoxicity of pediatric anesthetics (PAN) has received extensive attention in the field of anesthesia, which has been listed as a potential problem affecting public health by NFDA of the United States. Previous studies on rodents and non-human primates indicate that inhalation of anesthetics early after birth can induce long-term and sustained impairment of learning and memory function, as well as changes in brain function. Many anti-oxidant drugs, dexmedetomidine, as well as a rich living environment and exercise have been proven to reduce the neurotoxicity of anesthetics. In this paper, we summarize the research progress, molecular mechanisms and current intervention measures of anesthetic neurotoxicity.

Detection of Transient Increase of Cerebral Blood Flow and Reversible Neuronal Dysfunction by Iodine-123-Iomazenil Single Photon Emission Computed Tomography After Cerebral Hyperperfusion Syndrome After Revascularization Surgery for Moyamoya Disease

BACKGROUND

Early and late images of single photon emission computed tomography (SPECT) using ¹²³I-iomazenil (¹²³I-IMZ) can demonstrate cerebral blood flow and cortical neuronal viability. Hyperperfusion syndrome is one of the serious complications after revascularization surgery for moyamoya disease; therefore, the real-time observation of the hemodynamics and neuronal viability is important for the treatment after the revascularization. Here we report, a case of moyamoya disease where ¹²³I-IMZ SPECT had a significant efficacy to delineate the hemodynamics and transient neuronal dysfunction in hyperperfusion state after revascularization.

CASE DESCRIPTION

A 47-year-old woman presented with motor aphasia 3 days after superficial temporal artery-middle cerebral artery anastomosis with indirect revascularization. Magnetic resonance imaging (MRI) on the same day showed no new ischemic changes but high intensities along the left frontal sulci observed on fluid-attenuated inversion recovery images, and ¹²³I-IMZ SPECT demonstrated the increased uptake on the early images and the decreased uptake on the late images around the anastomosis site. The patient was completely recovered 1 month after surgery, and abnormal changes on MRI and ¹²³I-IMZ SPECT returned to normal along with the symptom withdrawal.

CONCLUSIONS

These findings indicate that ¹²³I-IMZ SPECT could be the index for the treatment of revascularization for obstructive vascular diseases such as moyamoya disease.

Neuroprotective effects of andrographolide on chronic cerebral hypoperfusion-induced hippocampal neuronal damage in rats possibly via PTEN/AKT signaling pathway

To explore the potential effects of andrographolide on chronic cerebral hypoperfusion (CCH)-induced neuronal damage as well as the underlying mechanisms. Rat CCH model was established by 2-vessel occlusion (2VO). The CCH rats received andrographolide treatment for 4 weeks. The neuron loss was detected by using neuronal nuclei (NeuN) immunofluorescent staining. The expression levels of phospho-phosphatase and tensin homolog deleted on chromosome ten (p-PTEN), protein kinase B (AKT), p-AKT, and cysteinyl aspartate specific proteinase-3 (Caspase-3) proteins were accessed by Western blotting. Moreover, the neuronal apoptosis of hippocampus tissues was detected via terminal deoxynucleotidyl transferase- mediated dUTP nick end labeling (TUNEL) staining. CCH reduced the number of NeuN-positive cells, while the number was significant increased after andrographolide treatment. CCH increased the proteins expression level of p-PTEN, Caspase-3, and decreased the p-AKT, which were reversed by andrographolide treatment. Furthermore, andrographolide treatment also down-regulated CCH-induced TUNEL-apoptosis rate. Our results suggest that the PTEN/AKT pathway may be modulated by andrographolide and the damaging effects of CCH on hippocampus may be ameliorated by andrographolide treatment. Andrographolide may act as a potential therapeutic approach for chronic ischemic insults.

Dynamic Changes in miR-126 Expression in the Hippocampus and Penumbra Following Experimental Transient Global and Focal Cerebral Ischemia-Reperfusion

miR-126 which is considered one of the most important miRNAs for maintaining vascular integrity, plays an important role in neuroprotection after cerebral ischemia-reperfusion (I-R). Moreover, vascular endothelial growth factor A (VEGFA), sprouty-related EVH1 domain-containing protein 1 (SPRED1), and Raf-1 are also involved in physiological processes of vascular endothelial cells (ECs). This study investigated how miR-126 changes with reperfusion time in different brain tissues after global cerebral ischemia and focal cerebral ischemia and examined the underlying mechanism miR-126 involving VEGFA, SPRED1, and Raf-1 after I-R. The results indicated decreases in the levels of miR-126-3p and miR-126-5p expression in mice and gerbils after I-R, consistent with the results after oxygen and glucose deprivation and reperfusion (OGD/R) in PC12 cells. Glial cells were activated as neuronal damage gradually increased after I-R. Inhibition of miR-126-3p exacerbated the OGD/R-induced cell death and reduced cell viability. After miR-126-3p inhibition, the levels of SPRED1 and VEGFA expression were increased, and p-Raf-1 expression was decreased after OGD/R. Moreover, based on the intervention of miR-126-3p inhibition, we found that the expression of p-Raf-1 was significantly increased after the intervention of siSPRED1, while it was not statistically significant after intervention of siVEGFA. The reduction of miR-126 expression after global and focal cerebral ischemia exacerbated neuronal death, which was closely related to increasing the SPRED1 activation and inhibiting the Raf-1 expression.

Application of Magnetic Resonance Imaging Molecular Probe in the Treatment of Cerebral Infarction and Paralysis of Hind Limbs with Neural Stem Cells Derived from Pluripotent Stem Cells

This paper used magnetic resonance diffusion kurtosis imaging to observe the acute cerebral infarction model of mice, and studied the imaging changes of ischemic penumbra after perfusion of model for rat middle cerebral artery occlusion experiment, and combined with the physiologic changes of mice. The damage of neurons was evaluated by the evolution of N-methyl-D-aspartate receptors to provide a corresponding imaging basis for the diagnosis and treatment of ischemic penumbra. The research shows that the diffusivity value decreases with time, and the diffusion kurtosis increases with time. The difference in diffusivity between different parts of the same time point and the same part of the same point (except the edge relative to the normal area) is statistically different. Learning significance was set at P < 0.05. The expression of N-methyl-D-aspartate receptor 2A in tissue homogenate increased overall, and expression in synaptic membrane, synaptic membrane, and light membrane decreased. The expression of N-methyl-D-aspartate acid receptor 2B in tissue homogenate, synaptic membrane, and light cell membrane decreased, and it increased first and then decreased in the synaptic membrane. The studies confirmed that magnetic resonance imaging has a certain clinical diagnostic value for the penumbra evolution mechanism and neuronal injury of acute cerebral infarction, which deserves further study.

Silencing of microRNA-146a alleviates the neural damage in temporal lobe epilepsy by down-regulating Notch-1

This study aimed to evaluate the specific regulatory roles of microRNA-146a (miRNA-146a) in temporal lobe epilepsy (TLE) and explore the related regulatory mechanisms. A rat model of TLE was established by intraperitoneal injection of lithium chloride-pilocarpine. These model rats were injected intracerebroventricularly with an miRNA-146a inhibitor and Notch-1 siRNA. Then, neuronal damage and cell apoptosis in the cornu ammonis (CA) 1 and 3 regions of the hippocampus were assessed. SOD and MDA levels in the hippocampus were detected by chromatometry, and IL-1β, IL-6, and IL-18 levels were detected by ELISA. Then, we evaluated the expression levels of caspase-9, GFAP, Notch-1, and Hes-1 in the hippocampus. The interaction between Notch-1 and miRNA-146a was assessed by a dual luciferase reporter gene assay. A rat model of TLE was successfully established, which exhibited significantly increased miRNA-146a expression in the hippocampus. Silencing of miRNA-146a significantly alleviated the neuronal damage and cell apoptosis in the CA1 and CA3 regions of the hippocampus in TLE rats and decreased MDA, IL-1β, IL-6, and IL-18 levels and increased SOD levels in the hippocampus of TLE rats. In addition, silencing of miRNA-146a significantly decreased the expression levels of caspase-9, GFAP, Notch-1, and Hes-1 in the hippocampus of TLE rats. Notch-1 was identified as a target of miRNA-146a and silencing of Notch-1 aggravated the neuronal damage in the CA1 and CA3 regions. Silencing of miRNA-146a alleviated the neuronal damage in the hippocampus of TLE rats by down-regulating Notch-1.

[Protection Effect of Dexamethasone on the Memory Impairment and Neuronal Damage of Neonate Rats that Repeatedly Suffered Sevoflurane Exposure]

OBJECTIVE

To investigate the protection effect of dexamethasone (DXMS) on the memory impairment and neuronal damage of neonate rats that caused by sevoflurane (SEVO) exposure.

METHODS

5-days-old newborn SD rats were randomly divided into normal group (NC group) (10 rats), SEVO group (10 rats) and SEVO+DXMS group (10 rats). Rats of SEVO group and SEVO+DXMS group were exposed to 2.5% SEVO 2 h per day for 1 week, meanwhile the rats of SEVO+DXMS group were given 20 mg/kg DXMS treatment before exposure and the normal group was given the same amount of placebo and carrier gas as control. All rats were fed normally till infancy. Then the Morris water maze test was used to assess the learning and memory function of rats of each group. HE and Nissl staining were used to observe the histomorphology and neuronal changes in the hippocampus of rats. ELISA was performed to test the changes in nitric oxide (NO), superoxide dismutase (SOD) and malondialdehyde (MDA) level in brain tissues. The expression of silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), fork head protein transcription factor 3α (FOXO3α) mRNA in brain tissue was detected by qRT-PCR. Western blot was used to explore the changes in SIRT1 and caspase-3 protein expression of hippocampus.

RESULTS

Compared with the NC group, the pathologic damage of hippocampus tissues was severely in SEVO group, and the number of neuronal cells was decreased as well. After SEVO intervention, the degree of pathologic damage was alleviated, and the number of neuronal cells was significantly increased. The Morris water maze test showed that the escape latency, number of platform crossing and target quadrant retention time between SEVO group and SEVO+DXMS group were significant different. The level of NO and MDA in brain of SEVO+DXMS group was significantly decreased than that of SEVO group, while the level of SOD was increased. qRT-PCR showed that the mRNA levels of SIRT1, PGC-1α and FOXO3α in SEVO+DXMS group were significantly higher those in SEVO group, but mRNA level of SIRT1 was still significantly lower than that of NC group. Western blot showed that the expression of SIRT1 protein in SEVO+DXMS group was significantly higher than that of SEVO group, and the expression of caspase-3 was reduced in SEVO+DXMS compared with SEVO group.

CONCLUSION

DXMS could reduce the level of oxidative stress and suppress the apoptosis of neuronal cells, reduce SEVO-induced brain damage in neonatal rats and improve learning and memory ability in infant rats.

Seawater Immersion Aggravates Early Mitochondrial Dysfunction and Increases Neuronal Apoptosis After Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of death and disability in naval warfare. Due to the unique physiochemical properties of seawater, immersion in it exacerbates TBI and induces severe neural damage and complications. However, the characteristics and underlying mechanisms of seawater-immersed TBI remain unclear. Mitochondrial dysfunction is a major cause of TBI-associated brain damage because it leads to oxidative stress, decrease in energy production, and apoptosis. Thus, the present study aimed to further elucidate the current understanding of the pathology of seawater-immersed TBI, particularly the role of mitochondrial dysfunction, using a well-defined rat model of fluid percussion injury and a stretch injury model comprising cultured neurons. The biochemical and pathological markers of brain-related and neuronal injuries were evaluated. Histological analysis suggested that seawater immersion enhanced brain tissue injury and induced a significant increase in apoptosis in rats with TBI. Additionally, lactate dehydrogenase release occurred earlier and at higher levels in stretched neurons at 24 h after seawater immersion, which was consistent with more severe morphological changes and enhanced apoptosis. Furthermore, seawater immersion induced more rapid decreases in mitochondrial membrane potential, adenosine triphosphate (ATP) content, and H⁺-ATPase activity in the cortices of TBI rats. In addition, the immunochemical results revealed that seawater immersion further attenuated mitochondrial function in neurons exposed to stretch injury. The increases in neuronal damage and apoptosis triggered by seawater immersion were positively correlated with mitochondrial dysfunction in both in vivo and in vitro models. Thus, the present findings strengthen the current understanding of seawater-immersed TBI. Moreover, because seawater immersion aggravates mitochondrial dysfunction and contributes to post-traumatic neuronal cell death, it is important to consider mitochondria as a therapeutic target for seawater-immersed TBI.

MicroRNA-365 Knockdown Prevents Ischemic Neuronal Injury by Activating Oxidation Resistance 1-Mediated Antioxidant Signals

MicroRNA-365 (miR-365) is upregulated in the ischemic brain and is involved in oxidative damage in the diabetic rat. However, it is unclear whether miR-365 regulates oxidative stress (OS)-mediated neuronal damage after ischemia. Here, we used a transient middle cerebral artery occlusion model in rats and the hydrogen peroxide-induced OS model in primary cultured neurons to assess the roles of miR-365 in neuronal damage. We found that miR-365 exacerbated ischemic brain injury and OS-induced neuronal damage and was associated with a reduced expression of OXR1 (Oxidation Resistance 1). In contrast, miR-365 antagomir alleviated both the brain injury and OXR1 reduction. Luciferase assays indicated that miR-365 inhibited OXR1 expression by directly targeting the 3'-untranslated region of Oxr1. Furthermore, knockdown of OXR1 abolished the neuroprotective and antioxidant effects of the miR-365 antagomir. Our results suggest that miR-365 upregulation increases oxidative injury by inhibiting OXR1 expression, while its downregulation protects neurons from oxidative death by enhancing OXR1-mediated antioxidant signals.

Therapeutic potential of endothelial progenitor cells in a rat model of epilepsy: Role of autophagy

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This is the first report showing EPCs therapeutic effects in PTZ-induced epilepsy.

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Intravenously administered EPCs homed into the epileptic rat hippocampus.

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EPCs amend the memory and locomotor activity deficits related to epilepsy.

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EPCs ameliorate epilepsy-associated alterations in neurotransmitters and autophagy.

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EPCs mitigate concomitant histological and vascular anomalies.

Epilepsy is one of the most well-known neurological conditions worldwide. One-third of adult epileptic patients do not respond to antiepileptic drugs or surgical treatment and therefore suffer from the resistant type of epilepsy. Stem cells have been given substantial consideration in the field of epilepsy therapeutics. The implication of pathologic vascular response in sustained seizures and the eminent role of endothelial progenitor cells (EPCs) in maintaining vascular integrity tempted us to investigate the potential therapeutic effects of EPCs in a pentylenetetrazole (PTZ)-induced rat model of epilepsy. Modulation of autophagy, a process that enables neurons to maintain an equilibrium of synthesis, degradation and subsequent reprocessing of cellular components, has been targeted. Intravenously administered EPCs homed into the hippocampus and amended the deficits in memory and locomotor activity. The cells mitigated neurological damage and the associated histopathological alterations and boosted the expression of brain-derived neurotrophic factor. EPCs corrected the perturbations in neurotransmitter activity and enhanced the expression of the downregulated autophagy proteins light chain protein-3 (LC-3), beclin-1, and autophagy-related gene-7 (ATG-7). Generally, these effects were comparable to those achieved by the reference antiepileptic drug, valproic acid. In conclusion, EPCs may confer therapeutic effects against epilepsy and its associated behavioural and biochemical abnormalities at least in part via the upregulation of autophagy. The study warrants further research in experimental and clinical settings to verify the prospect of using EPCs as a valid therapeutic strategy in patients with epilepsy.

Suspected poisoning in beef cattle from ingestion of Prosopis nigra pods in north-western Argentina

The aim of this paper was to present the first report of Prosopis nigra poisoning of cattle in Argentina. Outbreaks occurred in five farms located in Salta and Santiago del Estero provinces. All animals were examined, euthanized and necropsied. Clinical signs included tongue protrusion, twitches and tremors of muscles of mastication, weight loss and lethargy. Severe atrophy of the masseter, buccinator and lingual muscles was observed, along with neuronal vacuolation in the nuclei of the trigeminal, facial, and hypoglossus nerves. These findings and the clinical signs are consistent with results obtained in animals, spontaneously and experimentally intoxicated with Prosopis juliflora in previous studies. Several species of this genus are native to Argentina. Farmers should be warned about the suspected toxicity by Prosopis nigra, since this species has wide geographical distribution in the country.

Disruption of Brain Redox Homeostasis, Microglia Activation and Neuronal Damage Induced by Intracerebroventricular Administration of S-Adenosylmethionine to Developing Rats

S-Adenosylmethionine (AdoMet) concentrations are highly elevated in tissues and biological fluids of patients affected by S-adenosylhomocysteine hydrolase deficiency. This disorder is clinically characterized by severe neurological symptoms, whose pathophysiology is not yet established. Therefore, we investigated the effects of intracerebroventricular administration of AdoMet on redox homeostasis, microglia activation, synaptophysin levels, and TAU phosphorylation in cerebral cortex and striatum of young rats. AdoMet provoked significant lipid and protein oxidation, decreased glutathione concentrations, and altered the activity of important antioxidant enzymes in cerebral cortex and striatum. AdoMet also increased reactive oxygen (2',7'-dichlorofluorescein oxidation increase) and nitrogen (nitrate and nitrite levels increase) species generation in cerebral cortex. Furthermore, the antioxidants N-acetylcysteine and melatonin prevented most of AdoMet-induced pro-oxidant effects in both cerebral structures. Finally, we verified that AdoMet produced microglia activation by increasing Iba1 staining and TAU phosphorylation, as well as reduced synaptophysin levels in cerebral cortex. Taken together, it is presumed that impairment of redox homeostasis possibly associated with microglia activation and neuronal dysfunction caused by AdoMet may represent deleterious pathomechanisms involved in the pathophysiology of brain damage in S-adenosylhomocysteine hydrolase deficiency.

A Review on the Role of Inflammation in Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental condition that impairs quality of life in social, academic, and occupational contexts for both children and adults. Although a strong neurobiological basis has been demonstrated, the pathophysiology of ADHD is still poorly understood. Among the proposed mechanisms are glial activation, neuronal damage and degeneration, increased oxidative stress, reduced neurotrophic support, altered neurotransmitter metabolism, and blood-brain barrier disruption. In this way, a potential role of inflammation has been increasingly researched. However, evidence for the involvement of inflammation in ADHD is still scarce and comes mainly from (1) observational studies showing a strong comorbidity of ADHD with inflammatory and autoimmune disorders; (2) studies evaluating serum inflammatory markers; and (3) genetic studies. A co-occurrence of ADHD with inflammatory disorders has been demonstrated in a large number of subjects, suggesting a range of underlying mechanisms such as an altered immune response, common genetics, and environmental links. The evaluation of serum inflammatory markers has provided mixed results, likely due to the small sample sizes and high heterogeneity between biomarkers. However, there is evidence that increased inflammation during the early development may be a risk factor for ADHD symptoms. Although genetic studies have demonstrated a potential role for inflammation in this disorder, there is no clear evidence. To sum up, inflammation may be an important mechanism in ADHD pathophysiology, but more studies are still needed for a more precise conclusion.

Neuron-specific enolase levels as a marker for possible neuronal damage in idiopathic intracranial hypertension

Although formerly considered as a "benign" disease, the presence of some important problems such as vision loss, resistance to appropriate medical treatment and relapses suggests that neuronal damage might play a role in the pathophysiology of IIH. In order to demonstrate possible neuronal damage/dysfunction participating in IIH pathophysiology, we aimed to investigate the relationship between serum neuron-specific enolase (NSE) levels and clinical features in patients with idiopathic intracranial hypertension (IIH). Thirty-six patients with IIH, diagnosed according to the revised criteria, and 40 age, gender and body mass index-matched healthy controls were enrolled in this study after their consent. Serum samples were evaluated for NSE via enzyme-linked immunosorbent assay method. NSE levels were higher in the IIH group (23.7 ± 14.53 ng/ml) compared to the control group (22.7 ± 13.11 ng/ml), but the difference was not statistically significant (p = 0.824). There were also no statistically significant differences in NSE levels in IIH patients regarding the presence of visual loss, relapse, oligoclonal bands and papilledema. We could not demonstrate any correlations between NSE levels and age, body mass index, cerebrospinal fluid opening pressure and disease duration. The present study is the first to analyze NSE levels in IIH patients and showed no significant difference between patients and controls, and also between different clinical subgroups of IIH patients.

Control of stress-induced depressive disorders by So-ochim-tang-gamibang, a Korean herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

So-ochim-tang-gamibang (SOCG) is a Korean herbal medicine formula that has been applied to treat depressive moods and depression associated somatoform pain. This decoction consists of Cyperus rotundus L. (Cyperi Rhizoma), Lindera aggregata (Sims) Kosterm. (Linderae Radix), Aquilaria agallochum (Lour.) Roxb. ex Finl. (Aquilariae Resinatum Lignum), Glycyrrhiza uralensis Fisch. (Glycyrrhizae Radix) Platycodon grandiflorum (Jacq.) A. DC. (Platycodi Radix), and Citrus aurantium L. (Aurantii Fructus). The aim of this study is to assess antidepressant-like effects of SOCG and to investigate its possible cellular and molecular mechanisms.

MATERIAL AND METHODS

Using chronic restraint stress animal model, effects of SOCG on depressive-like behaviors, corticosterone, and hippocampal expressions of a neurotrophic factor and an apoptotic marker, were investigated. Mice were exposed to restraint stress 6h per day over a period of two weeks, and orally administrated either SOCG (30, 100, or 300mg/kg/day). The depressive-like behaviors were analyzed by forced swimming test and open field test. The serum levels of corticosterone were measured by enzyme-linked immunosorbent assay. Expressions of caspase-3 and BDNF in the hippocampus were analyzed by immunofluorescence. Further, effects of SOCG were examined in corticosterone-treated PC12 cells. Cellular toxicity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays. Real-time PCR was applied to investigate the cellular expression levels of Bax, Bcl-2, and BDNF. The levels of caspase-3 and BDNF were examined by Western blotting.

RESULTS

Administration of SOCG not only reduced immobility time of restraint-stressed mice in a dose-dependent manner, but also significantly increased the distance mice moved and the number of crossings in the open field test. Further, SOCG significantly reduced the serum level of corticosterone and expression of caspase-3, while increased expression of BDNF in vivo. SOCG increased cell viability in corticosterone treated PC12 cells, which was accompanied by decreased caspase-3 expression and the ratio of Bax/Bcl-2 mRNA expression as well as increased BDNF expression in vitro.

CONCLUSIONS

Taken together, our data suggested that SOCG may have potential as an antidepressant agent controlling depressive behaviors and corticosterone-induced neuronal damage caused by chronic stress.

Glycine Administration Alters MAPK Signaling Pathways and Causes Neuronal Damage in Rat Brain: Putative Mechanisms Involved in the Neurological Dysfunction in Nonketotic Hyperglycinemia

High glycine (GLY) levels have been suggested to induce neurotoxic effects in the central nervous system of patients with nonketotic hyperglycinemia (NKH). Since the mechanisms involved in the neuropathophysiology of NKH are not totally established, we evaluated the effect of a single intracerebroventricular administration of GLY on the content of proteins involved in neuronal damage and inflammatory response, as well as on the phosphorylation of the MAPK p38, ERK1/2, and JNK in rat striatum and cerebral cortex. We also examined glial fibrillary acidic protein (GFAP) staining, a marker of glial reactivity. The parameters were analyzed 30 min or 24 h after GLY administration. GLY decreased Tau phosphorylation in striatum and cerebral cortex 30 min and 24 h after its administration. On the other hand, synaptophysin levels were decreased in striatum at 30 min and in cerebral cortex at 24 h after GLY injection. GLY also decreased the phosphorylation of p38, ERK1/2, and JNK 30 min after its administration in both brain structures. Moreover, GLY-induced decrease of p38 phosphorylation in striatum was attenuated by N-methyl-D-aspartate receptor antagonist MK-801. In contrast, synuclein, NF-κB, iκB, inducible nitric oxide synthase and nitrotyrosine content, and GFAP immunostaining were not altered by GLY infusion. It may be presumed that the decreased phosphorylation of MAPK associated with alterations of markers of neuronal injury induced by GLY may contribute to the neurological dysfunction observed in NKH.