Spatiotemporal characteristics of astroglial death in the rat hippocampo‐entorhinal complex following pilocarpine‐induced status epilepticus

Abstract

Recently we reported that astroglial loss and subsequent gliogenesis in the dentate gyrus play a role in epileptogenesis following pilocarpine-induced status epilepticus (SE). In the present study we investigated whether astroglial damages in the hippocampo-entorhinal complex following SE are relevant to pathological or electrophysiological properties of temporal lobe epilepsy. Astroglial loss/damage was observed in the entorhinal cortex and the CA1 region at 4 weeks and 8 weeks after SE, respectively. These astroglial responses in the hippocampo-entorhinal cortex were accompanied by hyperexcitability of the CA1 region (impairment of paired-pulse inhibition and increase in excitability ratio). Unlike the dentate gyrus and the entorhinal cortex, CA1 astroglial damage was protected by conventional anti-epileptic drugs. alpha-Aminoadipic acid (a specific astroglial toxin) infusion into the entorhinal cortex induced astroglial damage and changed the electrophysiological properties in the CA1 region. Astroglial regeneration in the dentate gyrus and the stratum oriens of the CA1 region was found to originate from gliogenesis, while that in the entorhinal cortex and stratum radiatum of the CA1 region originated from in situ proliferation. These findings suggest that regional specific astroglial death/regeneration patterns may play an important role in the pathogenesis of temporal lobe epilepsy.

Knockdown of phospholipase C-β1 in the medial prefrontal cortex of male mice impairs working memory among multiple schizophrenia endophenotypes

“…38 Every sixth section in the series throughout the entire mPFC from selected mice was used for immunohistochemistry. Sections were stained by incubation with rabbit antiPLCβ1 primary antibody (1:100; Santa Cruz Biotechnology) and then with horseradish peroxidase (HRP) conjugated secondary antibody.…”

Phospholipase C β4 in the Medial Septum Controls Cholinergic Theta Oscillations and Anxiety Behaviors

“…Tissues were processed and immunostained as previously described (Kim et al, 2008). Briefly, animals were perfused transcardially with PBS followed by 4% paraformaldehyde in 0.1 M phosphate buffer (PB), pH 7.4, under urethane anesthesia (1.5 g/kg, i.p.).…”

“…For quantification of PLC-␤4 immunofluorescence in RNA interference (RNAi)-mediated PLC-␤4 knockdown mice, we have performed the cell count in the medial septal area according to the previous description (Kim et al, 2008(Kim et al, , 2009a. Briefly, PLC-␤4 immunofluorescent images (10 sections/mice) were captured in the same region (500 ϫ 500 m).…”

“…Bonferroni's test was used for post hoc comparisons. A value of p Ͻ 0.05 was considered statistically significant (Kim et al, 2008(Kim et al, , 2009a.…”

Altered PLCβ-1 expression in the gerbil hippocampal complex following spontaneous seizure

“…Bonferroni's test was used for post-hoc comparisons. P values ＜ 0.01 or 0.05 were considered statistically significant (30)(31)(32)36).…”