Systems neuroscienceDynamic seizure-related changes in extracellular signal-regulated kinase activation in a mouse model of temporal lobe epilepsy
Section snippets
Animals and pilocarpine treatment
The pilocarpine mouse model of recurrent seizures has been described in detail in previous studies (Peng et al 2004, Peng and Houser 2005). Briefly, young adult (6–8 weeks of age) C57BL/6 male mice (20–27 g; Harlan, Indianapolis, IN, USA) were used, and sustained seizures were induced in experimental animals by the administration of pilocarpine, a muscarinic cholinergic agonist. Animals were divided randomly into experimental and control groups, and all were injected with scopolamine methyl
Patterns of pERK labeling in control mice
Previous studies have described the distribution and abundance of ERK1/2 proteins and their mRNAs in the hippocampal formation (Fiore et al 1993, Thomas and Hunt 1993, Flood et al 1998). However, descriptions of the basal patterns of activated (phosphorylated) ERK are limited and have emerged primarily from descriptions of control tissue in studies of ERK activation following experimental manipulations. More detailed descriptions of the normal patterns of pERK labeling were needed in rostral
Discussion
This study demonstrated several unique features of pERK labeling in control and epileptic animals. First, in contrast to expected low levels of activated ERK in control mice, distinct pERK labeling was present in a sizeable subset of neurons throughout the hippocampal formation. Second, neuronal pERK labeling was strikingly decreased in pilocarpine-treated animals compared with controls during the periods between spontaneous seizures. Interestingly, this decrease in pERK labeling extended
Acknowledgments
This work was supported by Veterans Affairs Medical Research Funds (C.R.H.) and National Institutes of Health grant NS046524 (C.R.H.). We thank Christine Farrar for conducting the Western blot analyses, Yliana Cetina for expert assistance with the seizure monitoring, and Drs. Tom O'Dell and Istvan Mody for helpful discussions.
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