Search Results (30)

This study investigated the striatopallidal complex’s involvement in status epilepticus (SE) caused by morphological neurodegenerative changes in a post-natal immature developing brain in a lithium−pilocarpine male Wistar albino rat model of mesial temporal lobe epilepsy. One hundred experimental pups were grouped by age as follows: 12, 15, 18, 21, and 25 days. SE was induced by lithium−pilocarpine. Brain sections were microscopically examined by Fluoro-Jade B fluorescence stain at intervals of 4, 12, 24, and 48 h and 1 week after SE. Each interval was composed of four induced SE pups and a control. Fluoro-Jade B positive neurons in the dorsal striatum (DS) were screened and plotted on stereotaxic rat brain maps. The DS showed consistent neuronal damage in pups aged 18, 21, and 25 days. The peak of the detected damage was observed in pups aged 18 days, and the start of the morphological sequela was observed 12 h post SE. The neuronal damage in the DS was distributed around its periphery, extending medially. The damaged neurons showed intense Fluoro-Jade B staining at the intervals of 12 and 24 h post SE. SE neuronal damage was evidenced in the post-natal developing brain selectively in the DS and was age-dependent with differing morphological sequela. Full article

Brain ischemia, a condition in which the brain is deprived of blood flow, can lead to a stroke due to blocked or unstable blood vessels. Global cerebral ischemia (GCI), characterized by an interruption in blood flow, deprives the brain of oxygen and nutrients, producing reactive oxygen species (ROS) that trigger cell death, which kills nerve cells. Microplastics (MPs), tiny environmental pollutants, can enter the human body through contaminated food, water, disposable items, cosmetics, and more. Once in the brain, MPs can increase neuroinflammation by overstimulating inflammatory factors such as microglia. MPs can also damage neurons by scratching myelin and microtubules, slowing signal transduction, causing cognitive impairment, and leading to neuronal death. Furthermore, microtubule damage may result in the release of phosphorylated tau proteins, potentially linked to Alzheimer’s disease. We hypothesized that MPs could exacerbate neuroinflammation and microtubule destruction after GCI, leading to increased neuronal death. To test this hypothesis, we administered MPs (0.5 µm) orally at a dose of 50 mg/kg before and after inducing GCI. Staining techniques such as Fluoro-Jade B (FJB), ionized calcium-binding adaptor molecule 1 (Iba-1), cluster of differentiation 68 (CD68), myelin basic protein (MBP), and microtubule-associated protein 2 (MAP2) were used, along with Western blot analysis for interleukin-6 (IL-6), TNF-α, tau-5, and phospho-tau (S396) to evaluate the effects of MPs on neuronal cell death, neuroinflammation, and microtubule destruction. The results showed that MP accumulation significantly increased neuroinflammation, microtubule disruption, and neuronal cell death in the GCI-MP group compared to the GCI-vehicle group. Therefore, this study suggests that MP accumulation in daily life may contribute to the exacerbation of the disease, potentially leading to severe neuronal cell death after GCI. Full article

Background: Epilepsy is a prevalent and disabling neurological condition characterized by recurrent seizures. Approximately 50% of adults with active epilepsy have at least one comorbidity and they are at a greater risk of premature death than the general population. Gentiopicroside (Gent) is a primary component of Gentiana macrophylla Pall. that has been shown to have diverse pharmacological properties. However, its role in epileptic seizures in adult mice and its underlying mechanism of action remain obscure. We aimed to explore the anti-epileptic effect and mechanism of Gent on lithium/pilocarpine (Pilo)-induced epilepsy seizures in mice. Methods: In this study, we established a lithium/Pilo-induced epilepsy model, and Gent was first given to mice 30 min before Pilo administration. Then, we detected behavioral and histopathological changes through electrocorticographic (ECoG) measurements, Nissl staining, Fluoro-Jade B (FJB) staining, and immunohistochemical staining. We then used molecular biology techniques, such as Western blotting, quantitative polymerase chain reaction (qPCR) analysis, and the enzyme-linked immunosorbent assay (ELISA) to investigate the mechanisms of Gent in lithium/Pilo-induced epileptic seizures in mice and lipopolysaccharide (LPS)-induced inflammatory astrocytes. Results: We confirmed that Gent could prevent abnormal ECoG activity, behavioral changes, and neurodegeneration. Subsequently, we found Gent could downregulate the factors that could promote apoptosis (i.e., the NR2B/CaMKII/CREB signaling cascade) and neuroinflammatory-related factors (i.e., the TLR4/NF-κB signaling cascade). Conclusions: Gent could be a potential therapeutic agent for epilepsy, offering possibilities for both prevention and treatment. Our research establishes a preliminary experimental framework for ongoing studies into Gent’s efficacy as a treatment for epilepsy. Full article

Methamphetamine (METH) is a drug of abuse, which induces behavioral sensitization following repeated doses. Since METH alters blood pressure, in the present study we assessed whether systolic and diastolic blood pressure (SBP and DBP, respectively) are sensitized as well. In this context, we investigated whether alterations develop within A1/C1 neurons in the vasomotor center. C57Bl/6J male mice were administered METH (5 mg/kg, daily for 5 consecutive days). Blood pressure was measured by tail-cuff plethysmography. We found a sensitized response both to SBP and DBP, along with a significant decrease of catecholamine neurons within A1/C1 (both in the rostral and caudal ventrolateral medulla), while no changes were detected in glutamic acid decarboxylase. The decrease of catecholamine neurons was neither associated with the appearance of degeneration-related marker Fluoro-Jade B nor with altered expression of α-synuclein. Rather, it was associated with reduced free radicals and phospho-cJun and increased heat shock protein-70 and p62/sequestosome within A1/C1 cells. Blood pressure sensitization was not associated with altered arterial reactivity. These data indicate that reiterated METH administration may increase blood pressure persistently and may predispose to an increased cardiovascular response to METH. These data may be relevant to explain cardiovascular events following METH administration and stressful conditions. Full article

Phenobarbital (PB) remains the first-line medication for neonatal seizures. Yet, seizures in many newborns, particularly those associated with perinatal ischemia, are resistant to PB. Previous animal studies have shown that in postnatal day P7 mice pups with ischemic stroke induced by unilateral carotid ligation, the tyrosine receptor kinase B (TrkB) antagonist ANA12 (N-[2-[[(hexahydro-2-oxo-1H-azepin-3-yl)amino]carbonyl]phenyl]-benzo[b]thiophene-2-carboxamide, 5 mg/kg) improved the efficacy of PB in reducing seizure occurrence. To meet optimal standards of effectiveness, a wider range of ANA12 doses must be tested. Here, using the unilateral carotid ligation model, we tested the effectiveness of higher doses of ANA12 (10 and 20 mg/kg) on the ability of PB to reduce seizure burden, ameliorate cell death (assessed by Fluoro-Jade staining), and affect neurodevelopment (righting reflex, negative geotaxis test, open field test). We found that a single dose of ANA12 (10 or 20 mg/kg) given 1 h after unilateral carotid ligation in P7 pups reduced seizure burden and neocortical and striatal neuron death without impairing developmental reflexes. In conclusion, ANA12 at a range of doses (10–20 mg/kg) enhanced PB effectiveness for the treatment of perinatal ischemia-related seizures, suggesting that this agent might be a clinically safe and effective adjunctive agent for the treatment of pharmacoresistant neonatal seizures. Full article

The aim of the present study was to analyze the location of degenerating neurons in the dorsal (insular) claustrum (DCL, VCL) and the dorsal, intermediate and ventral endopiriform nucleus (DEn, IEn, VEn) in rat pups following lithium–pilocarpine status epilepticus (SE) induced at postnatal days [P]12, 15, 18, 21 and 25. The presence of Fluoro-Jade B-positive neurons was evaluated at 4, 12, 24, 48 h and 1 week later. A small number of degenerated neurons was observed in the CL, as well as in the DEn at P12 and P15. The number of degenerated neurons was increased in the CL as well as in the DEn at P18 and above and was highest at longer survival intervals. The CL at P15 and 18 contained a small or moderate number of degenerated neurons mainly close to the medial and dorsal margins also designated as DCl (“shell”) while isolated degenerated neurons were distributed in the VCl (“core”). In P21 and 25, a larger number of degenerated neurons occurred in both subdivisions of the dorsal claustrum. The majority of degenerated neurons in the endopiriform nucleus were found in the intermediate and caudal third of the DEn. A small number of degenerated neurons was dispersed in the whole extent of the DEn with prevalence to its medial margin. Our results indicate that degenerated neurons in the claustrum CL and endopiriform nucleus are distributed mainly in subdivisions originating from the ventral pallium; their distribution correlates with chemoarchitectonics of both nuclei and with their intrinsic and extrinsic connections. Full article

During adolescence, the brain is highly susceptible to alcohol-induced damage and subsequent neuroimmune responses, effects which may enhance development of an alcohol use disorder (AUD). Neuroimmune reactions are implicated in adolescent alcohol exposure escalating adulthood drinking. Therefore, we investigated whether intermittent alcohol exposure in male, adolescent rats (AIE) escalated adult drinking via two-bottle choice (2BC). We also examined the influence of housing environment across three groups: standard (group-housed with enrichment during 2BC), impoverished (group-housed without enrichment during 2BC), or isolation (single-housed without bedding or enrichment throughout). In the standard group immediately after AIE/saline and after 2BC, we also examined the expression of microglial marker, Iba1, reactive astrocyte marker, vimentin, and neuronal cell death dye, FluoroJade B (FJB). We did not observe an escalation of adulthood drinking following AIE, regardless of housing condition. Further, only a modest neuroimmune response occurred after AIE in the standard group: no significant microglial reactivity or neuronal cell death was apparent using this model, although some astrocyte reactivity was detected in adolescence following AIE that resolved by adulthood. These data suggest that the lack of neuroimmune response in adolescence in this model may underlie the lack of escalation of alcohol drinking, which could not be modified through isolation stress. Full article

Anethole (AN) is one of the major constituents of several plant oils, demonstrating plentiful pharmacological actions. Ischemic stroke is the main cause of morbidity and death worldwide, particularly since ischemic stroke therapeutic choices are inadequate and limited; thus, the development of new therapeutic options is indispensable. This study was planned to explore the preventive actions of AN in ameliorating cerebral ischemia/reperfusion-induced brain damage and BBB permeability leakage, as well as to explore anethole’s potential mechanisms of action. The proposed mechanisms included modulating JNK and p38 as well as MMP-2 and MMP-9 pathways. Sprague–Dawley male rats were randomly assigned into four groups: sham, middle cerebral artery occlusion (MCAO), AN125 + MCAO, and AN250 + MCAO. Animals in the third and fourth groups were pretreated with AN 125 or 250 mg/kg orally, respectively, for two weeks before performing middle cerebral artery occlusion (MCAO)-induced cerebral ischemic/reperfusion surgery. Animals that experienced cerebral ischemia/reperfusion exhibited amplified infarct volume, Evans blue intensity, brain water content, Fluoro-Jade B-positive cells, severe neurological deficits, and numerous histopathological alterations. MCAO animals exhibited elevated MMP-9 and MMP-2 gene expressions, enzyme activities, augmented JNK, and p38 phosphorylation. On the other hand, pretreatment with AN diminished the infarct volume, Evans blue dye intensity, brain water content, and Fluoro-Jade B-positive cells, improved the neurological score and enhanced histopathological examination. AN effectively lowered MMP-9 and MMP-2 gene expression and enzyme activities and diminished phosphorylated JNK, p38. AN decreased MDA content, amplified GSH/GSSG ratio, SOD, and CAT, decreased the serum and brain tissue homogenate inflammatory cytokines (TNF-α, IL-6, IL-1β), NF-κB, and deterred the apoptotic status. This study revealed the neuroprotective ability of AN against cerebral ischemia/reperfusion in rats. AN boosted blood–brain barrier integrity via modulating MMPs and diminished oxidative stress, inflammation, and apoptosis through the JNK/p38 pathway. Full article

Research reports using animal models of ischemic insults have demonstrated that oxcarbazepine (a carbamazepine analog: one of the anticonvulsant compounds) extends neuroprotective effects against cerebral or forebrain injury induced by ischemia and reperfusion. However, research on protective effects against ischemia and reperfusion cerebellar injury induced by cardiac arrest (CA) and the return of spontaneous circulation has been poor. Rats were assigned to four groups as follows: (Groups 1 and 2) sham asphyxial CA and vehicle- or oxcarbazepine-treated, and (Groups 3 and 4) CA and vehicle- or oxcarbazepine-treated. Vehicle (0.3% dimethyl sulfoxide/saline) or oxcarbazepine (200 mg/kg) was administered intravenously ten minutes after the return of spontaneous circulation. In this study, CA was induced by asphyxia using vecuronium bromide (2 mg/kg). We conducted immunohistochemistry for calbindin D-28kDa and Fluoro-Jade B histofluorescence to examine Purkinje cell death induced by CA. In addition, immunohistochemistry for 4-hydroxy-2-nonenal (4HNE) was carried out to investigate CA-induced oxidative stress, and immunohistochemistry for Cu, Zn-superoxide dismutase (SOD1) and Mn-superoxide dismutase (SOD2) was performed to examine changes in endogenous antioxidant enzymes. Oxcarbazepine treatment after CA significantly increased the survival rate and improved neurological deficit when compared with vehicle-treated rats with CA (survival rates ≥ 63.6 versus 6.5%), showing that oxcarbazepine treatment dramatically protected cerebellar Purkinje cells from ischemia and reperfusion injury induced by CA. The salvation of the Purkinje cells from ischemic injury by oxcarbazepine treatment paralleled a dramatic reduction in 4HNE (an end-product of lipid peroxidation) and increased or maintained the endogenous antioxidant enzymes (SOD1 and SOD2). In brief, this study shows that therapeutic treatment with oxcarbazepine after CA apparently saved cerebellar neurons (Purkinje cells) from CA-induced neuronal death by attenuating oxidative stress and suggests that oxcarbazepine can be utilized as a therapeutic medicine for ischemia and reperfusion brain (cerebellar) injury induced by CA. Full article

Clinical studies have demonstrated that dynamic changes in regional cerebral oxygen saturation (rSO₂) after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) have a role in predicting neurological outcomes after the return of spontaneous circulation (ROSC). Our study evaluated whether the timing of rSO₂ decline shortly after CPR reflects the severity of brain injury in a rat model of CA. Rats were subjected to different durations of asphyxia to produce variable severities of brain injury, due to CA. Time from ROSC to achieving the initial minimum rSO₂ was defined as T_nadir. A T_nadir cut-off of 24 min had optimal sensitivity and specificity for predicting good neurological outcomes at 72 h after ROSC (AUC, 0.88; sensitivity, 89%; specificity, 86%; p < 0.01). Immunohistochemistry at 72 h post-CA revealed that the number of Fluoro-Jade B positive degenerating neurons in the hippocampus CA1 sector were markedly higher in animals with T_nadir > 24 min than that in animals with T_nadir ≤ 24 min. There was no difference in the gene expressions of cytokines and mitochondrial fission proteins in the brain at 2 h after ROSC between rats with T_nadir > 24 min and with T_nadir ≤ 24 min. In conclusion, T_nadir can be a novel predictor of good neurological outcomes after CA/CPR. Full article

Cerebrovascular disease such as ischemic stroke develops cognitive impairment due to brain tissue damage including neural loss, demyelination and decrease in synaptic density. In the present study, we developed transient ischemia in the forebrain of the gerbil and found cognitive impairment using the Barnes maze test and passive avoidance test for spatial memory and learning memory, respectively. In addition, neuronal loss/death was detected in the Cornu Ammonis 1 (CA1) region of the gerbil hippocampus after the ischemia by cresyl violet histochemistry, immunohistochemistry for neuronal nuclei and histofluorescence with Fluoro-Jade B. Furthermore, in the CA1 region following ischemia, myelin and vesicular synaptic density were significantly decreased using immunohistochemistry for myelin basic protein and vesicular glutamate transporter 1. In the gerbils, treatment with COG-up^® (a combined extract of Erigeron annuus (L.) Pers. and Brassica oleracea Var.), which was rich in scutellarin and sinapic acid, after the ischemia, significantly improved ischemia-induced decline in memory function when compared with that shown in gerbils treated with vehicle after the ischemia. In the CA1 region of these gerbils, COG-up^® treatment significantly promoted the remyelination visualized using immunohistochemistry myelin basic protein, increased oligodendrocytes visualized using a receptor-interacting protein, and restored the density of glutamatergic synapses visualized using double immunofluorescence for vesicular glutamate transporter 1 and microtubule-associated protein, although COG-up^® treatment did not protect pyramidal cells (principal neurons) located in the CA1 region form the ischemic insult. Considering the current findings, a gerbil model of ischemic stroke apparently showed cognitive impairment accompanied by ischemic injury in the hippocampus; also, COG-up^® can be employed for improving cognitive decline following ischemia-reperfusion injury in brains. Full article

Lactoferrin (LF) was used at first as a vehicle to deliver non-soluble active compounds to the body, including the central nervous system (CNS). Nonetheless, it soon became evident that, apart from acting as a vehicle, LF itself owns active effects in the CNS. In the present study, the effects of LF are assessed both in baseline conditions, as well as to counteract methamphetamine (METH)-induced neurodegeneration by assessing cell viability, cell phenotype, mitochondrial status, and specific autophagy steps. In detail, cell integrity in baseline conditions and following METH administration was carried out by using H&E staining, Trypan blue, Fluoro Jade B, and WST-1. Western blot and immuno-fluorescence were used to assess the expression of the neurofilament marker βIII-tubulin. Mitochondria were stained using Mito Tracker Red and Green and were further detailed and quantified by using transmission electron microscopy. Autophagy markers were analyzed through immuno-fluorescence and electron microscopy. LF counteracts METH-induced degeneration. In detail, LF significantly attenuates the amount of cell loss and mitochondrial alterations produced by METH; and mitigates the dissipation of autophagy-related proteins from the autophagy compartment, which is massively induced by METH. These findings indicate a protective role of LF in the molecular mechanisms of neurodegeneration. Full article

(1) Background and Purpose: Global cerebral ischemia-induced severe hypoxic brain damage is one of the main causes of mortality and long-term neurologic disability even after receiving early blood reperfusion. This study aimed to test the hypothesis that atorvastatin potentially has neuroprotective effects in global cerebral ischemia (GCI). (2) Methods: We performed two sets of experiments, analyzing acute (1-week) and chronic (4-week) treatments. For the vehicle (Veh) and statin treatments, 1 mL of 0.9% saline and 5 mg/kg of atorvastatin (ATOR) were administered orally. For histological analysis, we used the following staining protocols: Fluoro-Jade B and NeuN, 4-hydroxynonenal, CD11b and GFAP, IgG, SMI71, and vWF. Finally, we evaluated the cognitive function with a battery of behavioral tests. (3) Results: The GCI-ATOR group showed significantly reduced neuronal death, oxidative stress, inflammation, and BBB disruption compared with the GCI-Veh group. Moreover, the GCI-ATOR group showed decreased endothelial damage and VV proliferation and had significantly improved cognitive function compared with the GCI-Veh group in both models. (4) Conclusions: ATOR has neuroprotective effects and helps recover the cognitive function after GCI in rats. Therefore, administration of atorvastatin may be a therapeutic option in managing GCI after CA. Full article

Autonomic dysfunction in the central nervous system (CNS) can cause death after recovery from a cardiac arrest (CA). However, few studies on histopathological changes in animal models of CA have been reported. In this study, we investigated the prevalence of neuronal death and damage in various brain regions and the spinal cord at early times after asphyxial CA and we studied the relationship between the mortality rate and neuronal damage following hypothermic treatment after CA. Rats were subjected to 7–8 min of asphyxial CA, followed by resuscitation and prompt hypothermic treatment. Eight regions related to autonomic control (the cingulate cortex, hippocampus, thalamus, hypothalamus, myelencephalon, and spinal cord) were examined using cresyl violet (a marker for Nissl substance) and Fluoro-Jade B (a marker for neuronal death). The survival rate was 44.5% 1 day post-CA, 18.2% 2 days post-CA and 0% 5 days post-CA. Neuronal death started 12 h post-CA in the gigantocellular reticular nucleus and caudoventrolateral reticular nucleus in the myelencephalon and lamina VII in the cervical, thoracic, lumbar, and sacral spinal cord, of which neurons are related to autonomic lower motor neurons. In these regions, Iba-1 immunoreactivity indicating microglial activation (microgliosis) was gradually increased with time after CA. Prompt hypothermic treatment increased the survival rate at 5 days after CA with an attenuation of neuronal damages and death in the damaged regions. However, the survival rate was 0% at 12 days after CA. Taken together, our study suggests that the early damage and death of neurons related to autonomic lower motor neurons was significantly related to the high mortality rate after CA and that prompt hypothermic therapy could increase the survival rate temporarily after CA, but could not ultimately save the animal. Full article

Oligodendrocytes, myelin-forming cells in the brain, are vulnerable to oxidative stress. Recent work indicates that air pollution causes demyelinating diseases such as multiple sclerosis. However, little is known about the mechanism of toxicity of ultrafine particulate matters (PMs) to oligodendrocytes. Here, we aimed to determine whether oligodendrocyte precursor cells (OPCs) and mature oligodendrocytes (mOLs) are more vulnerable to ultrafine urban PMs (uf-UPs) than other types of brain cells and damage to adult OPCs and mOLs in the mouse brain exposed to uf-UPs. For in vitro experiments, following exposure to various concentrations (2, 20, and 200 μg/mL) of uf-UPs, we measured survival rates, the amount of reactive oxygen species (ROS), and the total antioxidant capacities (TACs) of brain cells isolated from neonatal Sprague-Dawley rats. For animal experiments, after a four-week exposure to a uf-UP suspension (20 μL, 0.4 mg/mL), we enumerated the number of damaged cells and typed damaged cells in the white matter of the cerebellum of uf-UP-exposed mice. MTT assays and Hoechst staining demonstrated that OPCs and mOLs were more vulnerable to uf-UP-induced damage than astrocytes and cortical neurons at 2, 20, and 200 μg/mL of uf-UPs examined in this study (p < 0.05). Damage to OPCs and mOLs depended on uf-UP concentration. DCF assays and DHE staining indicated that the amount of ROS generated in OPCs and mOLs was significantly higher than in other brain cell types (p < 0.05). In contrast, TAC values in OPCs and mOLs were significantly lower than those of other brain cell types (p < 0.05). Fluoro-Jade B (FJB)-positive cells in the cerebellar white matter of the uf-UP-exposed group were significantly greater in number relative to the control group. Double immunofluorescence indicated that FJB-positive cells are NG2-positive adult OPCs and carbon anhydrase II-positive mOLs. Taken together, our findings suggest that oxidative stress induced by uf-UPs in the brain impairs adult OPCs and mOLs, causing demyelination and reducing the capacity for remyelination. Full article