Cultured Rat Cortical Cells Research Articles

Protective Effects of p-Coumaric Acid Isolated from Vaccinium bracteatum Thunb. Leaf Extract on Corticosterone-Induced Neurotoxicity in SH-SY5Y Cells and Primary Rat Cortical Neurons

Corticosterone (CORT)-induced oxidative stress and neurotoxicity can cause neuronal dysfunction and mental disorders. In the present study, we investigated the effects and mechanism of the HP-20 resin fraction of the water extract of Vaccinium bracteatum leaves (NET-D1602) and its bioactive compound p-coumaric acid on neuronal cell damage in SH-SY5Y cells and primary culture of rat cortical cells. NET-D1602 and p-coumaric acid significantly improved cell viability in CORT-induced neurotoxicity in SH-SY5Y cells and primary cultures of rat cortical cells, and increased the activities of antioxidant enzymes (superoxide dismutase and catalase) against CORT-induced neurotoxicity in SH-SY5Y cells. NET-D1602 and p-coumaric acid increased the phosphorylation levels of ERK1/2 and cAMP response element-binding protein (CREB) in cortical neurons. In addition, CREB phosphorylation by NET-D1602 and p-coumaric acid was dramatically reversed by PKA, c-Raf/ERK, PI3K, and mTOR inhibitors. Lastly, we demonstrated the neuroprotective effects of NET-D1602 (3 and 10 μg/mL) and p-coumaric acid (3 and 10 μM) via increased CREB phosphorylation in CORT-induced neurotoxicity mediated via the ERK1/2, Akt, and mTOR pathways. These results suggest that p-coumaric acid is a potential neuroprotective component of NET-D1602, with the ability to protect against CORT-induced neurotoxicity by regulating ERK1/2, Akt, and mTOR-mediated CREB phosphorylation.

Protective effects of calcium ions via L-type calcium channels and NMDA receptors on prostaglandin E2-induced apoptosis in rat cortical cells.

Calcium ions mediate a variety of physiological responses of developing neurons including survival. The purpose of this study was to examine the effect of calcium influx through L-type calcium channels (LTCCs) or NMDA receptors on prostaglandin E2 (PGE2)-induced apoptosis in rat cortical cells. Cultures of rat cortical cells were prepared from an embryonic day 18 rat neocortex. After culturing for 2 or 8days in vitro (DIV), the cells were subjected to PGE2 treatment for 48h. FPL64176, an LTCC agonist, protected the cells at 2 and 8 DIV from PGE2-induced apoptosis. On the other hand, N-methyl-D-aspartate (NMDA), an agonist of NMDA receptor, protected the cells from PGE2-induced apoptosis only at 8 DIV. FPL64176 increased the calcium levels at 2 and 8 DIV, whereas NMDA increased the calcium levels only at 8 DIV. The protective effects of the LTCC agonist and NMDA on PGE2-induced apoptosis were blocked following treatment of the cells with protein kinase C inhibitors. Our results suggest that LTCCs and NMDA receptors modulate the cell death of developing cortical neurons possibly through a protein kinase C pathway.

Structurally different anabolic androgenic steroids reduce neurite outgrowth and neuronal viability in primary rat cortical cell cultures

The illicit use of anabolic androgenic steroids (AAS) among adolescents and young adults is a major concern due to the unknown and unpredictable impact of AAS on the developing brain and the consequences of this on mental health, cognitive function and behaviour. The present study aimed to investigate the effects of supra-physiological doses of four structurally different AAS (testosterone, nandrolone, stanozolol and trenbolone) on neurite development and cell viability using an in vitro model of immature primary rat cortical cell cultures. A high-throughput screening image-based approach, measuring the neurite length and number of neurons, was used for the analysis of neurite outgrowth. In addition, cell viability and expression of the Tubb3 gene (encoding the protein beta-III tubulin) were investigated. Testosterone, nandrolone, and trenbolone elicited adverse effects on neurite outgrowth as deduced from an observed reduced neurite length per neuron. Trenbolone was the only AAS that reduced the cell viability as indicated by a decreased number of neurons and declined mitochondrial function. Moreover, trenbolone downregulated the Tubb3 mRNA expression. The adverse impact on neurite development was neither inhibited nor supressed by the selective androgen receptor (AR) antagonist, flutamide, suggesting that the observed effects result from another mechanism or mechanisms of action that are operating apart from AR activation. The results demonstrate a possible AAS-induced detrimental effect on neuronal development and regenerative functions. An impact on these events, that are essential mechanisms for maintaining normal brain function, could possibly contribute to behavioural alterations seen in AAS users.

Neuronal Exosomes Secreted under Oxygen-Glucose Deprivation/Reperfusion Presenting Differentially Expressed miRNAs and Affecting Neuronal Survival and Neurite Outgrowth.

Ischemia/reperfusion is a key feature of acute ischemic stroke, which causes neuron dysfunction and death. Exosomes, small extracellular vesicles produced by most cell types, are implicated in the mediation of cellular interactions with their environment. Here, we investigated the contents and functions of exosomes from neurons under ischemic reperfusion injury. First, rat cortical primary neuronal cell cultures were placed in an oxygen- and glucose-deprived (OGD) medium, followed by reperfusion in a normoxic conditioned medium (OGD/R) to mimic ischemia/reperfusion in vitro. The neuron-derived exosomes were harvested from the conditioned medium under normoxia and OGD/R. Through next-generation sequencing, exosomal miRNA expression levels in normoxic and OGD/R condition were compared. Their functional activity in terms of neuron viability and quantitative analysis of neurite outgrowth were examined. The expression levels of 45 exosomal miRNAs were significantly different between normoxic and OGD/R conditions. Bioinformatics analysis of dysregulated exosomal miRNAs identified multiple pathways involved in cell survival and death processes and neuronal signaling. Moreover, treatment with exosomes from OGD/R to cultured cortical neurons significantly impaired neuronal cell viability and reduced neurite outgrowth in terms of the number of primary or total neurites as well as length of primary neurites, compared with exosomes from normoxic conditions. miRNA-packed exosomes released by neurons under OGD/R challenge may contribute to post ischemic neuronal injury and provide further understanding of the effect of stressed neurons on neighboring neuronal functions.

Memory-Enhancing Effects of Mangosteen Pericarp Water Extract through Antioxidative Neuroprotection and Anti-Apoptotic Action.

Mangosteen has long been utilized as a traditional medicine in Southeast Asia. Diverse extracts of mangosteen pericarp and its bioactive xanthones exhibit various bioactivities. However, the pharmacological potential of mangosteen pericarp water extract (MPW) has not been reported yet. This study used primary cultured rat cortical cells to investigate the effect of MPW on neurotoxicity. We found that MPW inhibited neurotoxicity and production of reactive oxygen species triggered by Aβ(25–35) or excitatory amino acids. MPW inhibited caspase 3 activation and DNA fragmentation in Aβ(25–35)- or N-methyl-D-aspartate-treated cells, suggesting an anti-apoptotic action. Additionally, MPW reduced lipid peroxidation and scavenged 1,1-diphenyl-2-picrylhydrazyl radicals, assuring its antioxidant property. Furthermore, MPW suppressed β-secretase and acetylcholinesterase activities. These findings prompted us to evaluate its effect on memory dysfunction in scopolamine-treated mice using Morris water maze test. Oral administration of MPW at the dosage of 50, 100, or 300 mg/kg for four days significantly decreased the latency time to find the platform and markedly increased the swimming time in the target quadrant. Taken together, our results suggest that MPW exerts memory-enhancing effect through antioxidative neuroprotection and anti-apoptotic action. Accordingly, MPW may have a potential to prevent or treat memory impairment associated with Alzheimer’s disease.

Glycyrrhizin Blocks the Detrimental Effects of HMGB1 on Cortical Neurogenesis After Traumatic Neuronal Injury.

Despite medical advances, neurological recovery after severe traumatic brain injury (TBI) remains poor. Elevated levels of high mobility group box protein-1 (HMGB1) are associated with poor outcomes; likely via interaction with receptors for advanced-glycation-end-products (RAGE). We examined the hypothesis that HMGB1 post-TBI is anti-neurogenic and whether this is pharmacologically reversible. Post-natal rat cortical mixed neuro-glial cell cultures were subjected to needle-scratch injury and examined for HMGB1-activation/neuroinflammation. HMGB1-related genes/networks were examined using genome-wide RNA-seq studies in cortical perilesional tissue samples from adult mice. Post-natal rat cortical neural stem/progenitor cell cultures were generated to quantify effects of injury-condition medium (ICM) on neurogenesis with/without RAGE antagonist glycyrrhizin. Needle-injury upregulated TNF-α/NOS-2 mRNA-expressions at 6 h, increased proportions of activated microglia, and caused neuronal loss at 24 h. Transcriptome analysis revealed activation of HMGB1 pathway genes/canonical pathways in vivo at 24 h. A 50% increase in HMGB1 protein expression, and nuclear-to-cytoplasmic translocation of HMGB1 in neurons and microglia at 24 h post-injury was demonstrated in vitro. ICM reduced total numbers/proportions of neuronal cells, but reversed by 0.5 μM glycyrrhizin. HMGB1 is activated following in vivo post mechanical injury, and glycyrrhizin alleviates detrimental effects of ICM on cortical neurogenesis. Our findings highlight glycyrrhizin as a potential therapeutic agent post-TBI.

Role of pyroptosis in bilirubin-induced microglial injury

To study whether pyroptosis is involved in the bilirubin-induced injury of primary cultured rat cortical microglial cells. Primary cultured rat cortical microglial cells were randomly administered with 30 μmol/L bilirubin (bilirubin group), 30 μmol/L bilirubin following 30 μmol/L VX-765 pretreatment (VX-765+bilirubin group), or an equal volume of dimethyl sulfoxide (control group). Modified MTT assay was used to measure the viability of microglial cells. Western blot was used to measure the expression of the pyroptosis-related proteins Caspase-1 and gasdermin D (GSDMD). Lactate dehydrogenase (LDH)-release assay was used to evaluate the cytotoxicity of microglial cells. EtBr/EthD2 with different molecular weights (394 Da/1 293 Da) was used to measure the size of plasma membrane pores. ELISA was used to measure the level of the inflammatory factor interleukin-1β (IL-1β) in culture supernatant. After bilirubin stimulation, the viability of microglial cells decreased and LDH release increased, both in a time-dependent manner. Compared with the control group, the bilirubin group had a significantly higher positive rate of small-molecule EtBr passing through the cell membrane (P<0.001), while there was no significant difference in the pass rate of large-molecule EthD2 between groups (P>0.05). The expression of activated Caspase-1 significantly increased at 0.5 hour after bilirubin stimulation (P<0.05), and that of activated GSDMD significantly increased at 6 hours after bilirubin stimulation (P<0.05). The release of IL-1β significantly increased at 6 hours after bilirubin stimulation and reached the peak at 24 hours (P<0.001). Compared with the bilirubin group, the VX-765+bilirubin group had a significant increase in cell viability (P<0.05) and significant reductions in the expression of activated GSDMD, the pass rate of EtBr, and the release of LDH and IL-1β (P<0.05). Pyroptosis is involved in bilirubin-induced injury of primary cultured microglial cells.

Apoptosis in Neuronal Populations of C. Elegans through Exposure to Caffeine

Caffeine is the most widely used psychoactive drug in the world and forms a mild dependency in individuals who overuse the drug for an extended period. Other stimulant drugs, including methamphetamines, have been shown to induce apoptosis in the brain’s reward pathways, suggesting that stimulants may lead to apoptosis to lasting neuronal damage. Caffeine has been shown to induce apoptosis in gastric cancer cells in vitro as well as neonatal rat brain and cortical cell cultures. In C. elegans, the homolog of the p‐53 pathway is the CEP‐1 pathway. Caffeine induces apoptosis in human osteoblasts via the p53, Bax, and caspase 3 pathways. However, other studies suggest that caffeine produces inverse effects; caffeine exposure has been reported to increase longevity of Caenorhabditis elegans through activation of the IGF‐1 signaling pathway. Our current data clarifies the relationship between caffeine exposure and CEP‐1 via TG‐12, a C. elegans strain with CEP‐1:: GFP fusion gene.Here we discuss the results of caffeine exposure on TG‐12 worms. Early data indicates that exposure to high levels of caffeine leads to apoptosis in the nerve ring region of the worm. Here we attempt to identify the affected neuronal populations. We plan to further investigate the relationship between CEP‐1 and caffeine exposure in a dose‐dependent fashion via qRT‐PCR.Support or Funding InformationThis work was supported and funded by the Nueva School. The Shen Lab at Stanford University provided lab equipment and OH11061 worms. Worms and technical support were provided by Caenorhabditis Genetics Center (CGC) ‐ College of Biological Sciences

Aminothioneine activates BDNF expression and enhances learning and memory in mice.

The previous study demonstrated that hot water extract of golden oyster mushrooms (Aminothioneine®) and ergothioneine, which is a hydrophilic antioxidant and contained at high levels in golden oyster mushrooms, increased neuronal differentiation in the hippocampal dentate gyrus of mice and have antidepressant-like effects in mice. Here, we investigated the effect of Aminothioneine on BDNF expression in primary cultures of cortical cells and learning and memory in mice. In primary cultures of rat cortical cells, Aminothioneine, but not ergothioneine, significantly increased expression levels of BDNF mRNA. Aminothioneine also increased the levels of BDNF expression in the hippocampus of mice. Aminothioneine significantly increased freezing behavior in the test session of the contextual fear conditioning test. In the test session of the novel object location recognition test, Aminothioneine-administered mice spent more time exploring the object at the novel location. Taken together, Aminothioneine increased expression levels of BDNF in cultured neurons and hippocampus of mice. Also, Aminothioneine enhances learning and memory in mice. Because it has been reported that higher expression levels of BDNF are associated with slower cognitive decline during aging, Aminothioneine could act as a memory stabilizer in an aging brain.

In vitro cellular uptake and neuroprotective efficacy of poly-arginine-18 (R18) and poly-ornithine-18 (O18) peptides: critical role of arginine guanidinium head groups for neuroprotection.

We have previously demonstrated that Cationic Arginine-Rich Peptides (CARPs) and in particular poly-arginine-18 (R18; 18-mer of arginine) exhibit potent neuroprotective properties in both in vitro and in vivo neuronal injury models. Based on the current literature, there is a consensus that arginine residues by virtue of their positive charge and guanidinium head group is the critical element for imparting CARP neuroprotective properties and their ability to traverse cell membranes. This study examined the importance of guanidinium head groups in R18 for peptide cellular uptake, localization, and neuroprotection. This was achieved by using poly-ornithine-18 (O18; 18-mer of ornithine) as a control, which is structurally identical to R18, but possesses amino head groups rather than guanidino head groups. Epifluorescence and confocal fluorescence microscopy was used to examine the cellular uptake and localization of the FITC-conjugated R18 and O18 in primary rat cortical neurons and SH-SY5Y human neuroblastoma cell cultures. An in vitro cortical neuronal glutamic acid excitotoxicity model was used to compare the effectiveness of R18 and O18 to inhibit cell death and intracellular calcium influx, as well as caspase and calpain activation. Fluorescence imaging studies revealed cellular uptake of both FITC-R18 and FITC-O18 in neuronal and SH-SY5Y cells; however, intracellular localization of the peptides differed in neurons. Following glutamic acid excitotoxicity, only R18 was neuroprotective, prevented caspases and calpain activation, and was more effective at reducing neuronal intracellular calcium influx. Overall, this study demonstrated that for long chain cationic poly-arginine peptides, the guanidinium head groups provided by arginine residues are an essential requirement for neuroprotection but are not required for entry into neurons.

A Feedforward Mechanism for Epileptogenesis Regulated by Lactate Dehydrogenase A

Abstract INTRODUCTION Despite the ketogenic diet's successful use since the 1920s, epilepsy as a disease of energy metabolism is a novel concept. We previously established that seizures deplete neuronal energy stores and reprogram neurons from aerobic to glycolytic metabolic phenotype, marked by upregulation of lactate dehydrogenase A (LDHA). LDHA has recently been shown to play a role in neuronal membrane depolarization and epileptogenesis. We show here that LDHA upregulation through HIF1a may lead to seizure formation. METHODS Resected tissue from 11 epileptic patients were probed for LDHA expression. To study the electrophysiological consequences of LDHA, we used a mixed rat cortical cell culture model on a microelectrode array (MEA). Furthermore, we developed a novel murine model of chronic focal cortical epilepsy to establish HIF1a's role in mediating LDHA expression and seizure formation. Finally, we used a lentivirus vector to directly upregulate LDHA in neurons cultured on an MEA to measure neuronal bursting. RESULTS We found LDHA increased significantly in epileptic tissue versus nonepileptic tissue. Induction of seizure activity in cultured neurons with low magnesium resulted in increased LDHA and subsequently increased baseline bursting over 10 d. Inhibition of LDHA activity with stiripentol and isosafrole decreased the overall burst frequency. Cells that were induced to upregulate LDHA via DMOG, an upstream HIF1a potentiator, showed a significant increase in baseline bursting activity. Furthermore, placement of cobalt, a HIF1a stabilizer, into the frontal cortex of mice caused chronic seizures emanating from perilesion cortex which showed increased LDHA. Finally, direct LDHA upregulation resulted in increased bursting activity confirming that LDHA may lead to seizure formation. CONCLUSION Overall, our data show that LDHA, regulated by HIF1a, can contribute to seizure development. These data suggest a novel molecular mechanism for the pathogenesis of epilepsy where seizures cause LDHA upregulation which then further drives seizures, leading to a cycle of epileptogenesis.

Inhibition of Oxidative Neurotoxicity and Scopolamine-Induced Memory Impairment by γ-Mangostin: In Vitro and In Vivo Evidence.

Among a series of xanthones identified from mangosteen, the fruit of Garcinia mangostana L. (Guttifereae), α- and γ-mangostins are known to be major constituents exhibiting diverse biological activities. However, the effects of γ-mangostin on oxidative neurotoxicity and impaired memory are yet to be elucidated. In the present study, the protective effect of γ-mangostin on oxidative stress-induced neuronal cell death and its underlying action mechanism(s) were investigated and compared to that of α-mangostin using primary cultured rat cortical cells. In addition, the effect of orally administered γ-mangostin on scopolamine-induced memory impairment was evaluated in mice. We found that γ-mangostin exhibited prominent protection against H2O2- or xanthine/xanthine oxidase-induced oxidative neuronal death and inhibited reactive oxygen species (ROS) generation triggered by these oxidative insults. In contrast, α-mangostin had no effects on the oxidative neuronal damage or associated ROS production. We also found that γ-mangostin, not α-mangostin, significantly inhibited H2O2-induced DNA fragmentation and activation of caspases 3 and 9, demonstrating its antiapoptotic action. In addition, only γ-mangostin was found to effectively inhibit lipid peroxidation and DPPH radical formation, while both mangostins inhibited β-secretase activity. Furthermore, we observed that the oral administration of γ-mangostin at dosages of 10 and 30 mg/kg markedly improved scopolamine-induced memory impairment in mice. Collectively, these results provide both in vitro and in vivo evidences for the neuroprotective and memory enhancing effects of γ-mangostin. Multiple mechanisms underlying this neuroprotective action were suggested in this study. Based on our findings, γ-mangostin could serve as a potentially preferable candidate over α-mangostin in combatting oxidative stress-associated neurodegenerative diseases including Alzheimer's disease.

Anandamide Reduces the Toxic Synergism Exerted by Quinolinic Acid and Glutaric Acid in Rat Brain Neuronal Cells

The endocannabinoid system (ECS) regulates several physiological processes in the Central Nervous System, including the modulation of neuronal excitability via activation of cannabinoid receptors (CBr). Both glutaric acid (GA) and quinolinic acid (QUIN) are endogenous metabolites that, under pathological conditions, recruit common toxic mechanisms. A synergistic effect between them has already been demonstrated, supporting potential implications for glutaric acidemia type I (GA I). Here we investigated the possible involvement of a cannabinoid component in the toxic model exerted by QUIN + GA in rat cortical slices and primary neuronal cell cultures. The effects of the CB1 receptor agonist anandamide (AEA), and the fatty acid amide hydrolase inhibitor URB597, were tested on cell viability in cortical brain slices and primary neuronal cultures exposed to QUIN, GA, or QUIN + GA. As a pre-treatment to the QUIN + GA condition, AEA prevented the loss of cell viability in both preparations. URB597 only protected in a moderate manner the cultured neuronal cells against the QUIN + GA-induced damage. The use of the CB1 receptor reverse agonist AM251 in both biological preparations prevented partially the protective effects exerted by AEA, thus suggesting a partial role of CB1 receptors in this toxic model. AEA also prevented the cell damage and apoptotic death induced by the synergic model in cell cultures. Altogether, these findings demonstrate a modulatory role of the ECS on the synergic toxic actions exerted by QUIN + GA, thus providing key information for the understanding of the pathophysiological events occurring in GA I.

Toxic Impact of Anabolic Androgenic Steroids in Primary Rat Cortical Cell Cultures

The use of anabolic androgenic steroids (AASs) among non-athletes is a public health-problem, as abusers underestimate the negative effects associated with these drugs. The present study investigated the toxic effects of testosterone, nandrolone, stanozolol, and trenbolone, and aimed to understand how AAS abuse affects the brain. Mixed cortical cultures from embryonic rats were grown in vitro for 7 days and thereafter treated with increasing concentrations of AASs for 24 h (single-dose) or 3 days (repeated exposure). Cells were co-treated with the androgen-receptor (AR) antagonist flutamide, to determine whether the potential adverse effects observed were mediated by the AR. Cellular toxicity was determined by measuring mitochondrial activity, lactate dehydrogenase (LDH) release, and caspase-3/7 activity. Nandrolone, unlike the other AASs studied, indicated an effect on mitochondrial activity after 24 h. Furthermore, single-dose exposure with testosterone, nandrolone and trenbolone increased LDH release, while no effect was detected with stanozolol. However, all of the four steroids negatively affected mitochondrial function and resulted in LDH release after repeated exposure. Testosterone, nandrolone, and trenbolone caused their toxic effects by induction of apoptosis, unlike stanozolol that seemed to induce necrosis. Flutamide almost completely prevented AAS-induced toxicity by maintaining mitochondrial function, cellular integrity, and inhibition of apoptosis. Overall, we found that supra-physiological concentrations of AASs induce cell death in mixed primary cortical cultures, but to different extents, and possibly through various mechanisms. The data presented herein suggest that the molecular interactions of the AASs with the AR are primarily responsible for the toxic outcomes observed.

Comparative Action of Cardiotonic Steroids on Intracellular Processes in Rat Cortical Neurons.

Binding to Na+,K+-ATPase, cardiotonic steroids (CTS) activate intracellular signaling cascades that affect gene expression and regulation of proliferation and apoptosis in cells. Ouabain is the main CTS used for studying these processes. The effects of other CTS on nervous tissue are practically uncharacterized. Previously, we have shown that ouabain affects the activation of mitogen-activated protein kinases (MAP kinases) ERK1/2, p38, and JNK. In this study, we compared the effects of digoxin and bufalin, which belong to different subclasses of CTS, on primary culture of rat cortical cells. We found that CTS toxicity is not directly related to the degree of Na+,K+-ATPase inhibition, and that bufalin and digoxin, like ouabain, are capable of activating ERK1/2 and p38, but with different concentration and time profiles. Unlike bufalin and ouabain, digoxin did not decrease JNK activation after long-term incubation. We concluded that the toxic effect of CTS in concentrations that inhibit less than 80% of Na+,K+-ATPase activity is related to ERK1/2 activation as well as the complex profile of MAP kinase activation. A direct correlation between Na+,K+-ATPase inhibition and the degree of MAP kinase activation is only observed for ERK1/2. The different action of the three CTS on JNK and p38 activation may indicate that it is associated with intracellular signaling cascades triggered by protein-protein interactions between Na+,K+-ATPase and various partner proteins. Activation of MAP kinase pathways by these CTS occurs at concentrations that inhibit Na+,K+-ATPase containing the α1 subunit, suggesting that these signaling cascades are realized via α1. The results show that the signaling processes in neurons caused by CTS can differ not only because of different inhibitory constants for Na+,K+-ATPase.

A Line of MEA Signal Analysis Methods for Human Stem Cell-Derived and Other Dynamic Neuronal Cultures

A Line of MEA Signal Analysis Methods for Human Stem Cell-Derived and Other Dynamic Neuronal Cultures

Antioxidant and Neuroprotective Effects of N-((3, 4-Dihydro-2H-Benzo[h]chromen-2-yl) methyl)-4-Methoxyaniline in the Primary Cultured Rat Cortical Cells: Involvement of CREB Signaling

Antioxidant and Neuroprotective Effects of N-((3, 4-Dihydro-2H-Benzo[h]chromen-2-yl) methyl)-4-Methoxyaniline in the Primary Cultured Rat Cortical Cells: Involvement of CREB Signaling

Culture of Rodent Cortical, Hippocampal, and Striatal Neurons.

Neurons cultured from rodent central nervous system tissues represent important tools in the study of neurodegenerative disease mechanisms and neuroregenerative processes, including the survival- and axon growth-promoting properties of neurotrophic factors. This chapter presents a detailed protocol for the preparation of rat and mouse cortical, hippocampal, and striatal neuron cell cultures, using either embryonic or postnatal tissue with enzymatic digestion.

Antiepileptic Drug-Induced Apoptosis Was Prevented by L-Type Calcium Channel Activator in Cultured Rat Cortical Cells

Experimental data have shown that antiepileptic drugs cause neurodegeneration in developing rats. Valproate (VPA) is the drug of choice in primary generalized epilepsies, and carbamazepine (CBZ) is one of the most prescribed drugs in partial seizures. These drugs block sodium channels, thereby reducing sustained repetitive neuronal firing. The intracellular mechanisms whereby AEDs induce neuronal cell death are unclear. We examined whether AEDs induce apoptotic cell death in cultured cortical cells and whether calcium ions are involved in the AED-induced cell death. VPA and CBZ increased apoptotic cell death and induced morphological changes that were characterized by cell shrinkage and nuclear condensation or fragmentation. Incubation of cortical cultures with VPA or CBZ decreased phospho-Akt levels. CBZ decreased the intracellular calcium levels. On the other hand, FPL64176, an L-type calcium channel activator, increased the intracellular calcium levels and prevented the AED-induced apoptosis. Glycogen synthase kinase-3 inhibitors, such as alsterpaullone and azakenpaullone, prevented the AED-induced apoptosis. These results suggest that intracellular calcium level changes are associated with AEDs and apoptosis and that the activation of glycogen synthase kinase-3 is involved in the death of rat cortical neurons.

Neuroprotection of N-benzylcinnamide on scopolamine-induced cholinergic dysfunction in human SH-SY5Y neuroblastoma cells.

Alzheimer's disease, a progressive neurodegenerative disease, affects learning and memory resulting from cholinergic dysfunction. Scopolamine has been employed to induce Alzheimer's disease-like pathology in vivo and in vitro through alteration of cholinergic system. N-benzylcinnamide (PT-3), purified from Piper submultinerve, has been shown to exhibit neuroprotective properties against amyloid-β-induced neuronal toxicity in rat cortical primary cell culture and to improve spatial learning and memory of aged rats through alleviating oxidative stress. We proposed a hypothesis that PT3 has a neuroprotective effect against scopolamine-induced cholinergic dysfunction. PT-3 (125–200 nM) pretreatment was performed in human neuroblastoma SH-SY5Y cell line following scopolamine induction. PT-3 (125–200 nM) inhibited scopolamine (2 mM)-induced generation of reactive oxygen species, cellular apoptosis, upregulation of acetylcholinesterase activity, downregulation of choline acetyltransferase level, and activation of p38 and JNK signalling pathways. These findings revealed the underlying mechanisms of scopolamine-induced Alzheimer's disease-like cellular dysfunctions, which provide evidence for developing drugs for the treatment of this debilitating disease.