Hippocampal slices from long-term streptozotocin-injected rats are prone to epileptiform responses.
Evoked field potentials were recorded in the CA3, CA1 and dentate gyrus (DG) regions of hippocampal slices from rats injected with streptozotocin (STZ; 60 mg/kg i.p.), to detect whether STZ-induced diabetes entails changes in hippocampal excitability. No change in hippocampal responsiveness was observed in slices from diabetic rats, up to 3 weeks post-STZ. Repetitive population spikes (PSs) reminiscent of an epileptiform hyperexcitability were, however, recorded in CA3 > CA1 > DG areas after more than 4 weeks ('long-term') post-STZ, although the maximal amplitudes were not different in STZ-diabetic versus control rats. Intracellular recordings on CA3 pyramidal neurons confirmed that fimbrial stimulation evokes significantly more action potentials in neurons from 'long-term' STZ-diabetic versus control rats. This is the first report of the appearance of repetitive hippocampal responses, particularly in the seizure-prone CA3 area, as a long-term consequence of hyperglycemic STZ treatment in rat.
Margineanu
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DG
UCB s.a. Pharma Sector, Research and Development, Braine-l'Alleud, Belgium. doru.margineanu@ucb-group.com
Niespodziany
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Wülfert
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D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000503:physiopathology*; D004353:Drug Evaluation, Preclinical; D004827:Epilepsy / Q000139:chemically induced*; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D066298:In Vitro Techniques; D007267:Injections; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin / Q000633:toxicity*; D013997:Time Factors
D013311:Streptozocin