Resistance of neurofilaments to degradation, and lack of neuronal death and mossy fiber sprouting after kainic acid-induced status epilepticus in the developing rat hippocampus.
Neurofilament (NF) proteins, the major constituent of intermediate filaments in neurons, have an important role in cellular stability and plasticity. We have now studied the short-term (hours) and long-term (up to 1 week) effects of kainic acid (KA)-induced status epilepticus (SE) on the reactivity of NF proteins, and mossy fiber (MF) sprouting and neuronal death up to 4 weeks in 9-day-old rats. In Western blotting, the expression of the phosphorylation-independent epitopes of NF-L, NF-M, and NF-H rapidly but transiently increased after the treatment, whereas the phosphorylated NF-M remained elevated for 7 days. However, the treatment did not change the immunoreactivity of NF proteins, and no neuronal death or mossy fiber sprouting was detected at any time point. Our findings indicate seizure-induced reactivity of NF proteins but their resistance to degradation, which could be of importance in neuronal survival and may also prevent MF sprouting in the developing hippocampus.
Lopez-Picon
Francisco
F
Department of Pharmacology and Clinical Pharmacology, FIN-20520 Turku, Finland.
Puustinen
Niina
N
Kukko-Lukjanov
Tiina-Kaisa
TK
Holopainen
Irma E
IE
D000818:Animals; D000831:Animals, Newborn; D016923:Cell Death / Q000187:drug effects; D004195:Disease Models, Animal; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology*; D007382:Intermediate Filaments / Q000473:pathology* / Q000648:ultrastructure; D007608:Kainic Acid / Q000633:toxicity*; D016900:Neurofilament Proteins / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013226:Status Epilepticus / Q000139:chemically induced / Q000473:pathology*; D013997:Time Factors
D016900:Neurofilament Proteins; D007608:Kainic Acid