Global cerebral ischemia (GCI) is one of the main causes of hippocampal neuronal death. Ischemic damage can be rescued by early blood reperfusion. However, under some circumstances reperfusion itself can trigger a cell death process that is initiated by the reintroduction of blood, followed by the production of superoxide, a blood–brain barrier (BBB) disruption and microglial activation. Protocatechuic acid (PCA) is a major metabolite of the antioxidant polyphenols, which have been discovered in green tea. PCA has been shown to have antioxidant effects on healthy cells and anti-proliferative effects on tumor cells. To test whether PCA can prevent ischemia-induced hippocampal neuronal death, rats were injected with PCA (30 mg/kg/day) per oral (p.o) for one week after global ischemia. To evaluate degenerating neurons, oxidative stress, microglial activation and BBB disruption, we performed Fluoro-Jade B (FJB), 4-hydroxynonenal (4HNE), CD11b, GFAP and IgG staining. In the present study, we found that PCA significantly decreased degenerating neuronal cell death, oxidative stress, microglial activation, astrocyte activation and BBB disruption compared with the vehicle-treated group after ischemia. In addition, an ischemia-induced reduction in glutathione (GSH) concentration in hippocampal neurons was recovered by PCA administration. Therefore, the administration of PCA may be further investigated as a promising tool for decreasing hippocampal neuronal death after global cerebral ischemia.

Apocynin, also known as acetovanillone, is a natural organic compound structurally related to vanillin. Apocynin is known to be an inhibitor of NADPH (Nicotinamide adenine dinucleotide phosphate) oxidase activity and is highly effective in suppressing the production of superoxide. The neuroprotective effects of apocynin have been investigated in numerous brain injury settings, such as stroke, traumatic brain injury (TBI), and epilepsy. Our lab has demonstrated that TBI or seizure-induced oxidative injury and neuronal death were reduced by apocynin treatment. Several studies have also demonstrated that neuroblast production is transiently increased in the hippocampus after seizures. Here, we provide evidence confirming the hypothesis that long-term treatment with apocynin may enhance newly generated hippocampal neuronal survival by reduction of superoxide production after seizures. A seizure was induced by pilocarpine [(25 mg/kg intraperitoneal (i.p.)] injection. Apocynin was continuously injected for 4 weeks after seizures (once per day) into the intraperitoneal space. We evaluated neuronal nuclear antigen (NeuN), bromodeoxyuridine (BrdU), and doublecortin (DCX) immunostaining to determine whether treatment with apocynin increased neuronal survival and neurogenesis in the hippocampus after seizures. The present study indicates that long-term treatment of apocynin increased the number of NeuN⁺ and DCX⁺ cells in the hippocampus after seizures. Therefore, this study suggests that apocynin treatment increased neuronal survival and neuroblast production by reduction of hippocampal oxidative injury after seizures.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary cerebral small-vessel disease caused by mutations in the NOTCH3 gene. Classical pathogenic mechanisms are associated with cysteine gain or loss, but recent studies suggest that cysteine-sparing mutations might have a potential role as a pathogen. In comparison with CADASIL patients in Western countries, there are several differences in Asian patients: (1) prevalent locus of NOTCH3 mutations (exons 2–6 [particularly exon 4] vs. exon 11), (2) age at symptom onset, (3) prevalence of cerebral microbleeds and hemorrhagic stroke, (4) clinical symptoms, and (5) severity of white matter hyperintensities and typical involvement of the anterior temporal pole in magnetic resonance imaging. Both ethnicity and founder effects contribute to these differences in the clinical NOTCH3 spectrum in different cohorts. More functional investigations from diverse races are needed to clarify unknown but novel variants of NOTCH3 mutations. This review may broaden the spectrum of NOTCH3 variants from an Asian perspective and draw attention to the hidden pathogenic roles of NOTCH3 variants.

Epilepsy is one of the most common and severe brain diseases. The exact cause of epilepsy is unclear. Epilepsy often occurs following brain damage, such as traumatic brain injury (TBI) and ischemia. Cerebrolysin is a porcine brain peptide that is a unique neurotropic and neuroprotective agent. Cerebrolysin has been reported to increase neuroprotective effects after TBI, ischemia, and other CNS diseases. However, the effects of cerebrolysin on seizures are not known. Therefore, this study aimed to investigate the effects of neuropeptide cerebrolysin on neuronal death in the hippocampus after a seizure. To confirm the effects of cerebrolysin, we used a pilocarpine-induced seizure animal model. Cerebrolysin (2.5 ml/kg, i.p., once per day for 7 days) was immediately injected after a seizure induction. After 1 week, we obtained brain tissues and performed staining to histologically evaluate the potentially protective effects of cerebrolysin on seizure-induced neuronal death in the hippocampus. We found that cerebrolysin decreased hippocampal neuronal death after a seizure. In addition, an increase in brain-derived neurotrophic factor (BDNF) was confirmed through Western blot analysis to further support our hypothesis. Therefore, the present study suggests that the administration of cerebrolysin can be a useful therapeutic tool for preventing neuronal death after a seizure.

The diagnostic criteria for primary stabbing headache (PSH) in the 3rd beta edition of International Classification of Headache Disorders (ICDH-3 beta) were recently revised. In the ICDH-3 beta, PSH is defined as short-lasting head pain spontaneous occurring as a single stab or series of stabs without autonomic symptoms and involving all head areas (i.e., not limited to the ophthalmic branch region of the trigeminal nerve). The aim of this study was to investigate the validity of the ICHD-3 beta criteria for PSH in a clinic-based setting. We prospectively collected data from patients with complaint of headache with stabbing pain without apparent cause at an initial visit to a secondary-care hospital from March 2009 to March 2014. Patients were followed up for 2 weeks to assess changes in clinical characteristics and secondary causes of pain. Data from 280 patients with headache with stabbing pain without apparent cause were collected, and 245 patients were followed up for 2 weeks. Secondary causes for stabbing headache were observed in 9 patients (herpes zoster in 7 patients and Bell’s palsy in 2 patients) after 2 weeks. The remaining 236 patients fulfilled the diagnostic criteria for PSH according to ICHD-3 beta. Only 22 patients met the diagnostic criteria for PSH according to ICHD-2. All patients with headache with stabbing pain without cranial autonomic symptoms fulfilled the diagnostic criteria for PSH according to ICHD-3 beta at the initial visit. Secondary causes for headache with stabbing pain were revealed in a small proportion (3.7 %) of patients after 2 weeks of follow-up.

During seizure activity, glucose and Adenosine triphosphate (ATP) levels are significantly decreased in the brain, which is a contributing factor to seizure-induced neuronal death. Dichloroacetic acid (DCA) has been shown to prevent cell death. DCA is also known to be involved in adenosine triphosphate (ATP) production by activating pyruvate dehydrogenase (PDH), a gatekeeper of glucose oxidation, as a pyruvate dehydrogenase kinase (PDK) inhibitor. To confirm these findings, in this study, rats were given a per oral (P.O.) injection of DCA (100 mg/kg) with pyruvate (50 mg/kg) once per day for 1 week starting 2 h after the onset of seizures induced by pilocarpine administration. Neuronal death and oxidative stress were assessed 1 week after seizure to determine if the combined treatment of pyruvate and DCA increased neuronal survival and reduced oxidative damage in the hippocampus. We found that the combined treatment of pyruvate and DCA showed protective effects against seizure-associated hippocampal neuronal cell death compared to the vehicle-treated group. Treatment with combined pyruvate and DCA after seizure may have a therapeutic effect by increasing the proportion of pyruvate converted to ATP. Thus, the current research demonstrates that the combined treatment of pyruvate and DCA may have therapeutic potential in seizure-induced neuronal death.