Alterations in the Neurobehavioral Phenotype and ZnT3/CB-D28k Expression in the Cerebral Cortex Following Lithium-Pilocarpine-Induced Status Epilepticus: the Ameliorative Effect of Leptin

Ivermectin Exerts Anticonvulsant Effects Against Status Epilepticus Induced by Lithium-Pilocarpine in Rats via GABAA Receptor and Neuroinflammation Modulation: Possible Interaction of Opioidergic Pathways and KATP Channel with Nitrergic System

Status epilepticus (SE) is a critical medical emergency marked by persistent or rapidly repeating seizures, posing a threat to life. Using the lithium-pilocarpine-induced SE model, we decide to evaluate the anti-seizure effects of ivermectin as a positive allosteric modulator of GABAA receptor and the underlying mechanisms involved. Lithium chloride was injected intraperitoneally at a dose of 127 mg/kg, followed by the administration of pilocarpine at a dose of 60 mg/kg after a 20-h interval in order to induce SE. Subsequently, the rats received varying amounts of ivermectin (0.3, 1, 3, 5, and 10 mg/kg, i.p.) 30 min before the onset of SE. To study the underlying molecular mechanisms, we had pharmacological interventions of diazepam (1 mg/kg), glibenclamide and nicorandil as ATP-sensitive potassium channel blocker and opener (both 1 mg/kg, i.p.), naltrexone and morphine, as opioid receptor antagonist and agonist (1 mg/kg and 0.5 mg/kg, i.p., respectively). In addition, three nitric oxide inhibitors, namely, L-NAME (10 mg/kg, i.p.), 7-NI (30 mg/kg, i.p.), and aminoguanidine (100 mg/kg, i.p.), were administered to the rats in the experiment. Finally, we use ELISA and western blotting, respectively, to examine the amounts of pro-inflammatory cytokines (TNF-α and IL-1β), nitrite, and GABAA receptors in the rat hippocampal tissue. The study found that ivermectin, at doses of 3, 5, and 10 mg/kg, exerts anti-seizure effects and decrease Racine's scale SE score. Interestingly glibenclamide and naltrexone reduced the anti-seizure effects of ivermectin, and from other hand diazepam, nicorandil, morphine, L-NAME, 7-NI, and aminoguanidine, enhance the effects when co-administrated with subeffective dose of ivermectin. Additionally, the study found that ivermectin decreased the elevated levels of TNF-α and IL-1β following SE, while increased the reduced expression of GABAA receptors. Overall, these findings suggest that ivermectin has anti-seizure effects in a SE seizure which may be mediated by the modulation of GABAergic, opioidergic, and nitrergic pathways and KATP channels.

Effects of leptin treatment immediately after neonatal seizures on serum clusterin and VEGF levels and brain oxidative stress-related proteins and neurobehavioral phenotypes

The developing infant brain has a different response mechanism and repair potential for injury than the adult brain. There is an urgent need for new anticonvulsants to effectively control neonatal seizures while minimizing the drug's toxic damage to the developing brain. Leptin protects neuronal plasma membrane integrity, while it has clinical advantages in terms of anticonvulsant properties as well. This study aimed to evaluate the effect of immediate leptin treatment on the serum concentration of clusterin and vascular endothelial growth factor (VEGF), neuronal plasma membrane integrity-related proteins, and the neurobehavioral phenotypes following neonatal seizures. Leptin was injected i.p at a dose of 4 mg/kg 1 hour after daily 30 minutes prolonged seizures for consecutive 10 days. The serum biomarkers (clusterin and VEGF), and brain protein expression of ATF-4/GRP78/autophagy axis were measured by enzyme-linked immunosorbent assay and western blot in the acute phase (24 hours after the last seizures), respectively. Behavioral and histopathological phenotypes and seizure threshold were conducted from P23 to P34, respectively. There were rapid elevation of serum VEGF and clusterin as well as upregulated protein expression of ATF-4, GRP78, Beclin-1, and LC3 in the cerebral cortex and hippocampus following a neonatal seizure, which was restored by immediate treatment with leptin after seizures. In addition, leptin improved seizure-induced impaired neuropsychological, and cognitive functioning. Furthermore, leptin succeeded in ameliorating markers of neuronal excitability, including seizure threshold and hippocampal mossy fiber sprouting. In conclusion, this study verified that immediate treatment with leptin after neonatal seizures restored both rapid elevation of serum clusterin as well as upregulated protein expression of ATF-4/GRP78/autophagy axis in the cerebral cortex and hippocampus, which contributes to the recovery of neurological function.

Knockout of Transient Receptor Potential Melastatin 4 Channel Mitigates Cerebral Edema and Neuronal Injury After Status Epilepticus in Mice

This study aimed to evaluate whether the knockout of transient receptor potential melastatin 4 (TRPM4) could reduce cerebral edema and improve neurologic outcome in a mouse model of status epilepticus (SE). Wild-type (WT) (n = 61) and Trpm4-/- mice (n = 61) with behavioral seizures induced by lithium (10 mEq/kg) and pilocarpine (30-40 mg/kg) were terminated 2.5 hours after the onset of SE. After SE, 28 WT-SE and 27 Trpm4-/--SE mice were observed for 28 days and assessed for survival and cognitive function; the others were killed after 24 hours, 72 hours, or 7 days, and evaluated for cerebral edema and histological injury. In comparison to WT-SE mice, the mortality and cognitive deficit for Trpm4-/--SE mice following SE after 28 days were significantly ameliorated. Trpm4-/--SE mice also showed less water content and cerebral edema assessed by magnetic resonance imaging, and decreased blood-brain barrier breakdown after SE. Moreover, Trpm4 deficiency significantly mitigated neuronal loss, cellular necrosis and apoptosis in the hippocampus and piriform cortex and mitigated astrocytosis and microgliosis. In conclusion, this study suggests that Trmp4 may represent a new target for improving outcomes after SE.