Long-term effects of status epilepticus in the immature brain are specific for age and model.
OBJECTIVE
Status epilepticus (SE) is more common in children than adults and has a high mortality and morbidity rate. SE in adult rats results in long-term disturbances in learning and memory, as well as an enhanced seizure susceptibility to further seizures. In contrast, a number of studies suggest that the immature brain is less vulnerable to the morphologic and physiologic alterations after SE. The goal of this study was to determine whether the long-term consequences of SE during development on hippocampal plasticity and cognitive function are age and model specific.


METHODS
We used lithium-pilocarpine (Li-PC) to induce SE at different age points during development (P12, P16, P20) and evaluated the effects of this abnormal neural activity on spatial memory performance and seizure susceptibility in the animals beginning at P55, corresponding to young adulthood.


RESULTS
We demonstrated that SE at P12 did not result in any structural or functional changes detectable in adulthood, whereas SE at both P16 and P20 induced cell loss and mossy fiber sprouting within the hippocampus and cognitive impairment when the animals were tested as adults.


CONCLUSIONS
Whereas the seizure threshold to generalized seizures was not altered, animals with SE at P20 showed an increased susceptibility to kindling in adulthood.
Cilio
Maria Roberta
MR
Department of Neurology, Harvard Medical School, Center for Research in Pediatric Epilepsy, Children's Hospital Boston, Boston, Massachusetts, USA. cilio@opbg.net
Sogawa
Yoshimi
Y
Cha
Byung-Ho
BH
Liu
Xianzeng
X
Huang
Li-Tung
LT
Holmes
Gregory L
GL
D000367:Age Factors; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D003292:Convulsants; D004569:Electroencephalography / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology* / Q000503:physiopathology; D018021:Lithium Chloride; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D009949:Orientation / Q000187:drug effects / Q000502:physiology; D010862:Pilocarpine; D051381:Rats; D017207:Rats, Sprague-Dawley; D013226:Status Epilepticus / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology
D003292:Convulsants; D010862:Pilocarpine; D018021:Lithium Chloride