The Effects Of Minocycline On The Hippocampus In Lithium-Pilocarpine Induced Status Epilepticus In Rat: Relations With Microglial/Astrocytic Activation And Serum Mob Level

AIM: To investigate possible correlations between serum S100B levels and microglial/astrocytic activation in status epilepticus (SE) in lithium-pilocarpine-exposed rat hippocampi and whether serum S100B levels linearly reflect neuroinflammation. Additionally, to assess the effects of minocycline (M), an inhibitor of neuroinflammation. MATERIAL and METHODS: Rats were divided into 4 groups (6/group), namely, control (C), sham, SE, and SE+M. Animals were exposed to lithium-pilocarpine to induce SE in the SE and SE+M groups. Cardiac blood was collected to measure S100B levels, and coronal brain sections including the hippocampus were prepared to examine microglial/astrocytic activation and to evaluate neuroinflammation at day 7 of SE. RESULTS: Serum S100B levels, OX42 (+) microglia in CA1, and GFAP (+) astrocytes in both CA1 and dentate gyrus (DG) were higher in the SE+M group than in the C group. Most importantly, highly positive correlations were found between S100B levels and microglial activation in CA1, apart from astrocytic activation in CA1 and DG. Unexpectedly, microglial activation in CA1 and astrocytic activation in DG were also enhanced in the SE+M group compared with the C group. Moreover, M administration reversed the neuronal loss observed in DG during SE. CONCLUSION: These results suggest that serum S100B is a candidate biomarker for monitoring neuroinflammation and that it may also help predict diagnosis and prognosis.WoSScopu

Investigation of the Possible Protective Effects of Ketamine and Dantrolene on the Hippocampal Apoptosis and Spatial Learning in Rats Exposed to Repeated Electroconvulsive Seizures as a Model of Status Epilepticus

AIM: To evaluate the possible neuroprotective effects of ketamine and dantrolene on the hippocampal apoptosis and spatial learning in rats exposed to repeated electroconvulsive seizures (ECS) as a model of status epilepticus (SE). MATERIAL and METHODS: Twenty-four rats were assigned to 4 groups. 1st Group was Sham. 2nd Group was ECS: ECS was induced by ear electrodes via electrical stimulation. The same ECS protocol was applied to the 3th and 4th Groups which received ketamine (40 mg/kg s.c.) or dantrolene (5 mg/kg i.p.) 1 h before each ECS, respectively. Following 30 days of recovery, the cognitive status of the animals was evaluated via Morris Water Maze (MWM). The same experimental protocol was repeated 14 days afterward to evaluate the retention of the memory. Hippocampal apoptosis was examined in corresponding experimental groups. RESULTS: All the animals in four groups learned the task with no significant difference between groups in MWM. The ECS+ketamine group showed memory impairment 14 days afterward. ECS+dantrolene group was not different from controls. ECS caused long term apoptotic processes in dentate gyrus (DG) and non-apoptotic neuronal injury in CA1 and CA2. CONCLUSION: Dantrolene and ketamine inhibited apoptosis and showed neuroprotective effects. Although ketamine and dantrolene inhibited ECS-induced apoptosis and non-apoptotic injury, they did not produce similar effects on memory retention. It will be warranted to evaluate cognitive dysfunction by taking into consideration the other factors in addition to apoptosis and neurodegenerative changes