[Expression of α(5) subunit of extrasynaptic GABA(A) receptor in insular-kindled rats].

OBJECTIVE: To explore the expression of α(5) subunit of extrasynaptic GABA(A) receptor in insular electrical kindled rats and analyze its significance. METHODS: A total of 96 male Sprague-Dawley rats were divided randomly into kindled, sham-operated and control groups (n = 32). And each group was further divided into 2 sub-groups at different time points. Kindled group: insular electrical kindled via chronic electrical stimulation; Sham-operated group: electrode implantation without electrical stimulation; CONTROL GROUP: no operation at all. The number of hippocampal neurons was detected by Nissl staining; the mRNA of α(5) subunit of hippocampus by quantitative-polymerase chain reaction (q-PCR); the expression of α(5) subunit of hippocampus by immunohistochemistry. RESULTS: No significant difference existed in the number of hippocampal neurons between epileptic and normal rats (P > 0.05). The mRNA levels of α(5) subunit of hippocampus in the sham-operated and control groups were much higher than that of the kindled group at Day 1 and 7 post-sacrificing (P < 0.01). And the hippocampal expressions of α(5) subunit were much more in the sham-operated and control groups than that of the kindled group at Day 1 and 7 post-sacrificing (P < 0.01). CONCLUSION: The hippocampal expression of α(5) subunit decreases markedly in insular epilepsy. And α(5) subunit may play an important role in the occurrence and development of insular epilepsy.

[Expression of neuropeptides ghrelin and Nesfatin-1 in kainic acid kindling rats].

OBJECTIVE: To observed the post-seizure expression level of neuropeptides ghrelin and Nesfatin-1 between the untreated and treated groups in kainic acid-kindling rats and understand the significance of their basic expressions. METHODS: The male S-D rats were divided randomly into NS and VPA groups after seizure. Each group was divided into 7 subgroups of 3 h, 6 h, 12 h, 24 h, 3 d, 7 d and 14 d. And the blank group (without NS or VPA) and sham group (normal saline instead of kainic acid) were established. RIA (radioimmunoassay), ELISA (enzyme-linked immunosorbent assay) and immunohistochemistry were used to detect the expression levels of ghrelin and Nesfatin-1 in the serum and hypothalamus of kainic acid-kindling rats. RESULTS: Compared with the blank and sham groups, the seizure rats had a decreased expression of ghrelin while there was an elevated expression of Nesfatin-1 in hypothalamus. This trend was consistent with the serum expressions of deacylated ghrelin and Nesfatin-1. The expression of ghrelin became elevated at all stages in the VPA group. Especially the subgroups of 24 h (0.320 ± 0.007) and 7 d (0.284 ± 0.004) had a significant increase (P < 0.05) while their expression levels remained lowed than that of the blank group (0.342 ± 0.039). The expressions of Nesfatin-1 had a significant decrease (P < 0.05) in all VPA subgroups while they were higher than those in the blank group (0.124 ± 0.007). CONCLUSION: An accurate detection of serum expression level of deacylated ghrelin and Nesfatin-1 may reflect the fluctuation trend of neuropeptides in hypothalamus. It may offer a simple, sensitive and noninvasive method of diagnosing and treating epilepsy.

[mRNA expression of activity-regulated cytoskeletal-associated protein in hippocampus induced by insular-kindled rats].

OBJECTIVE: To investigate the expression of Arc mRNA in insular electrical kindled and single electrical stimulated rats and its significance. METHODS: Male SD rats were divided randomly into kindled group, single electrical stimulated group, sham-operated group and control group. Each group was divided into 2 sub-groups at different time points. Kindled group: establishing chronic insular electrical kindled model, decapitation to perform RT-PCR of Arc mRNA on hippocampus and to applying in situ hybridization of Arc mRNA on dentate gyrus; Single electrical stimulated group: using the same method as the kindled group with only electrical stimulation twice; Sham-operated group: using the same method to the kindled group without electrical stimulation; CONTROL GROUP: no surgery. RESULTS: Expression of Arc mRNA in the hippocampus of single electrical stimulated, sham-operated and control groups were 0.72 ± 0.14, 0.75 ± 0.16 and 0.71 ± 0.14 respectively. They were significantly less than the kindled group of 1.78 ± 0.43(P < 0.01) at 3 h. The expression of Arc mRNA had no significant difference (P > 0.05) among 4 groups at 6 h; in situ hybridization (cell count) of Arc mRNA showed the expression of Arc mRNA in the kindled group was 112.8 ± 6.0. And it was significantly higher than the other three groups of 46.25 ± 4.35, 45.25 ± 6.23, 44.75 ± 6.49 (P < 0.01) after 3 h, there were no significant difference among 4 groups at 6 h (P > 0.05). CONCLUSION: Insular epilepsy increase the expression of Arc mRNA in hippocampus. Arc may play an important role in the synaptic plasticity of insular epilepsy.