Changes in Neurofilament Protein NF-L and NF-H Immunoreactivity Following Kainic Acid-Induced Seizures
Version of Record online: 23 NOV 2002
Journal of Neurochemistry
Volume 62, Issue 2, pages 739–748, February 1994
How to Cite
Wang, S., Hamberger, A., Yang, Q. and Haglid, K. G. (1994), Changes in Neurofilament Protein NF-L and NF-H Immunoreactivity Following Kainic Acid-Induced Seizures. Journal of Neurochemistry, 62: 739–748. doi: 10.1046/j.1471-4159.1994.62020739.x
- Issue online: 23 NOV 2002
- Version of Record online: 23 NOV 2002
- Received April 1, 1993; revised manuscript received June 14, 1993; accepted June 14, 1993.
- Kainic acid;
- Neurofilament proteins;
- Neuronal plasticity
Abstract: Postlesion plasticity of neuronal processes might contribute to secondary spontaneous seizures after kainic acid administration. In this study, neurofilament (NF) proteins were examined following intraperitoneal injection of kainic acid, and special reference was given to temporal changes in quantity and quality of the NF light (NF-L) and heavy (NF-H) subunits. A pronounced decrease in phosphorylation-related immunoreactivity of NF-H occurred as early as 1 day after the injection in the amygdala/pyriform cortex, hippocampus, striatum, and dorsal cerebral cortex. A shift of NF-H from the phosphorylated to nonphosphorylated form was evident in immunoblots, suggesting dephosphorylation contributed to the decrease. Decreases in NF-L and phosphorylated NF-H contents in the limbic structure at 3 days were correlated with the increasing kainic acid doses from 2.5 to 10 mg/kg. The degradation pattern in immunoblots with antibodies against NF-L indicated that the decrease in NF-L was probably due to calcium-activated proteolysis. NF-L and phosphorylated NF-H contents secondarily increased from 9 days onward, with ∼20% above the control level of phosphorylated NF-H immunoreactivity at 27 days in the amygdala/pyriform cortex and ventral hippocampus. Immunohistochemical examination of the hippocampus revealed that an increase of NF staining in the mossy fiber system may contribute to the NF recovery in this region. Furthermore, the temporal changes of NF-L and phosphorylated NF-H contents were positively correlated with those of the neuronal cell adhesion molecule, a neuritic growth cone marker, substantiating postlesion regenerative reactions of NF proteins. Functional consequences of the NF plasticity remain to be identified.