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

Abstract

Although the phospholipase C (PLC)β-1 isoform is associated with spontaneous seizure and distinctively expressed in the telencephalon, the distribution of PLCβ-1 expression in the epileptic gerbil hippocampus remains controversial. Therefore, we determined whether PLCβ-1 is associated with spontaneous seizure in an animal model of genetic epilepsy. In the present study, PLCβ-1 immunoreactivity was down-regulated in seizure-sensitive (SS) gerbils more than in seizure-resistant (SR) gerbils. The expression of PLCβ-1 within calretinin (CR)-positive neurons was rarely detected within the dentate hilar region of SS gerbils. PLCβ-1 immunoreactivity in the hippocampus was significantly elevated as compared to that in pre-seizure SS gerbil 3 h post-ictal. These findings suggest that alterations in PLCβ-1 immunoreactivity in the SS gerbil hippocampus may be closely related to the epileptic state of the gerbil brain and transiently elevated PLCβ-1 protein levels following seizure episodes. Such alterations may be compensatory responses in the SS gerbil hippocampus. [BMB reports 2011; 44(9) : 566-571]

Alterations in hyperpolarization-activated cyclic nucleotide-gated cation channel (HCN) expression in the hippocampus following pilocarpine-induced status epilepticus

“…Since the measurement of nucleus size was used to correct the potential sampling bias, the diameter for each nucleus in the sample population was also measured at a magnification of 200 × and reduced to a mean diameter (D). The true estimate of cell number was then calculated using the Abercrombie correction method, as follows: N (per 250 × 250 μm 2 ) = n (T/T + D)/A, where N is the true cell number, T is the section thickness, and A is the measured area (per 250 × 250 μm 2 ) of each hippocampal region (30-34).…”

“…Bonferroni’s test was used for post-hoc comparisons. A P-value ＜ 0.01 or 0.05 was considered statistically significant (30-34).…”

Altered expression of adrenocorticotropic hormone in the epileptic gerbil hippocampus following spontaneous seizure

“…(9) and other previous studies (14, 15). Only animals with a consistent stage 4 or 5 seizure score according to the seizure severity rating scale of Loskota et al (34) were included in the present study, and were described as seizure sensitive (SS, n = 10) gerbils.…”

“…and perfused transcardially with phosphate-buffered saline (PBS, pH 7.4) followed by 4% paraformaldehyde in 0.1 M PBS. After this, tissue processing and immunohistochemistry processes were performed according to pervious described studies (14, 15). The sections were firstly incubated in mouse anti-ACTH antiserum (diluted 1：400; Peninsula, USA) containing 0.3% Triton X-100 and 2% normal goat serum overnight at room temperature.…”

“…Based on the results of the immunohistochemical study, we performed double immunofluorescent staining for both mouse anti-ACTH IgG (diluted 1：200; Peninsula) and rabbit anti-GABA A α1 receptor (1：2,500; Chemicon, USA) to confirm the cell type according to previous studies (14,15). In this immunofluorescence staining, we used secondary antibodies as Cy2 conjugated donkey anti-goat IgG (1：200; Amersham, USA) and Cy3 conjugated donkey anti-mouse IgG (1：200; Amersham) for 1 h at room temperature.…”