Persistent changes in action potential broadening and the slow afterhyperpolarization in rat CA1 pyramidal cells after febrile seizures.
Febrile (fever-induced) seizures (FS) are the most common form of seizures during childhood and have been associated with an increased risk of epilepsy later in life. The relationship of FS to subsequent epilepsy is, however, still controversial. Insights from animal models do indicate that especially complex FS are harmful to the developing brain and contribute to a hyperexcitable state that may persist for life. Here, we determined long-lasting changes in neuronal excitability of rat hippocampal CA1 pyramidal cells after prolonged (complex) FS induced by hyperthermia on postnatal day 10. We show that hyperthermia-induced seizures at postnatal day 10 induce a long-lasting increase in the hyperpolarization-activated current I(h). Furthermore, we show that a reduction in the amount of spike broadening and in the amplitude of the slow afterhyperpolarization following FS are also likely to contribute to the hyperexcitability of the hippocampus long term.
Kamal
Amer
A
Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Centre Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands.
Notenboom
Robbert G E
RG
de Graan
Pierre N E
PN
Ramakers
Geert M J
GM
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D005334:Fever / Q000150:complications; D006624:Hippocampus / Q000473:pathology*; D066298:In Vitro Techniques; D008297:Male; D017966:Pyramidal Cells / Q000187:drug effects / Q000503:physiopathology* / Q000528:radiation effects; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000209:etiology / Q000473:pathology*; D013779:Tetrodotoxin / Q000494:pharmacology
D000779:Anesthetics, Local; D011743:Pyrimidines; C082246:ICI D2788; D013779:Tetrodotoxin