Long-term Effects of Status Epilepticus in the Immature Brain Are Specific for Age and Model

• Published in: Epilepsia (Copenhagen) Vol. 44; no. 4; pp. 518 - 528
• Main Authors: Cilio, Maria Roberta, Sogawa, Yoshimi, Cha, Byung‐Ho, Liu, Xianzeng, Huang, Li‐Tung, Holmes, Gregory L.
• Format: Journal Article
• Language: English
• Published: Boston, MA, USA Blackwell Science Inc 01.04.2003; Blackwell
• Subjects: Age Factors; Animals; Apoptosis - drug effects; Apoptosis - physiology; Biological and medical sciences; Convulsants; Electroencephalography - drug effects; Epilepsy; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Hippocampus - drug effects; Hippocampus - pathology; Hippocampus - physiopathology; Immature brain; Learning; Lithium Chloride; Long-Term Potentiation - drug effects; Long-Term Potentiation - physiology; Male; Maze Learning - drug effects; Maze Learning - physiology; Medical sciences; Mental Recall - drug effects; Mental Recall - physiology; Nervous system (semeiology, syndromes); Neurology; Neuronal Plasticity - drug effects; Neuronal Plasticity - physiology; Orientation - drug effects; Orientation - physiology; Pilocarpine; Rats; Rats, Sprague-Dawley; Seizures; Status Epilepticus - chemically induced; Status Epilepticus - pathology; Status Epilepticus - physiopathology; Nervous system diseases; Rat; Epilepsy; Rodentia; Furan derivatives; Pilocarpine; Long term; Epilepsy-Seizures-Immature brain-Learning- Pilocarpine; Cerebral disorder; Vertebrata; Mammalia; Subintrant crisis; Animal; Central nervous system disease; Evolution; Models; Age; Hippocampus; Brain (vertebrata)
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1046/j.1528-1157.2003.48802.x

Purpose: 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.