Hippocampal distribution of IL-1β and IL-1RI following lithium-pilocarpine-induced status epilepticus in the developing rat

Abstract

The contribution of Interleukin-1β (IL-1β) to neuronal injury induced by status epilepticus (SE) in the immature brain remains unclear. The goal of this study was to determine the hippocampal expression of IL-1β and its type 1 receptor (IL-1RI) following SE induced by the lithium-pilocarpine model in fourteendays-old rat pups; control animals were given an equal volume of saline instead of the convulsant. IL-1β and IL-1RI mRNA hippocampal levels were assessed by qRT-PCR 6 and 24 h after SE or control conditions. IL-1β and IL-1RI expression was detected in the dorsal hippocampus by immunohistochemical procedures; Fluoro-Jade B staining was carried out in parallel sections in order to detect neuronal cell death. IL-1β mRNA expression was increased 6 h following SE, but not at 24 h; however IL-1RI mRNA expression was unaffected when comparing with the control group. IL-1β and IL-1RI immunoreactivity was not detected in control animals. IL-1β and IL-1RI were expressed in the CA1 pyramidal layer, the dentate gyrus granular layer and the hilus 6 h after SE, whereas injured cells were detected 24 h following seizures. Early expression of IL-1β and IL-1RI in the hippocampus could be associated with SE-induced neuronal cell death mechanisms in the developing rat.

Diverse Effects of an Acetylcholinesterase Inhibitor, Donepezil, on Hippocampal Neuronal Death after Pilocarpine-Induced Seizure

“…Rats were sacrificed three days after pilocarpine-induced seizures. FJB staining is known as a marker for selectively detecting degenerating neurons [ 23 ]. Neuronal death was increased in the donepezil-treated group when compared to the vehicle group in the CA1 and subiculum (Sub) areas of the hippocampus ( Figure 1 A).…”

Microglia and status epilepticus in the immature brain

“…Interestingly, the expression pattern was different in each hippocampal region. Whereas in CA1, these positive cells appeared to be neurons, in DG they appeared to be microglia; however, the cell phenotype was not accurately determined 47 . In this context, the exogenously applied IL‐1β promoted necrotic neuronal cell death in CA1 after SE through IL‐1R1 activation, 48 whereas it favored apoptotic cell death in DG independently of IL‐1RI activation 49 .…”

“…Whereas in CA1, these positive cells appeared to be neurons, in DG they appeared to be microglia; however, the cell phenotype was not accurately determined. 47 In this context, the exogenously applied IL‐1β promoted necrotic neuronal cell death in CA1 after SE through IL‐1R1 activation, 48 whereas it favored apoptotic cell death in DG independently of IL‐1RI activation. 49 Thus, this difference in the response of the hippocampal microglia is relevant considering the specific mechanisms of neuronal cell death identified in each hippocampal region.…”

Effects of Propolis on Spatial Memory Induced by Lithium Pilocarpine in the Experimental Status Epilepticus Model in the Rats

“…(Ahl et al2016). The incidence of epilepsy in childhood and elder ages was observed at the highest levels (Seino 2006, Ahl et al2016, Alverez -Croda et al 2016, Scorza FA, et al2009. Epilepsy affects around 50-70 million people in the world and 20-30% of them have seizures that cannot be controlled with every day anti-epileptic drugs (Marangoz 1997, Akpınar 2014.…”