Status epilepticus-induced changes in the subcellular distribution and activity of calcineurin in rat forebrain

• Published in: Neurobiology of disease Vol. 14; no. 3; pp. 483 - 493
• Main Authors: Kurz, Jonathan E, Rana, Annu, Parsons, J.Travis, Churn, Severn B
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2003; Elsevier
• Subjects: Animals; Calcineurin - metabolism; Calcium - metabolism; Calcium Signaling - physiology; Cell Compartmentation - physiology; Cell Nucleus - enzymology; Cerebral Cortex - enzymology; Cerebral Cortex - physiopathology; Dendrites - enzymology; Dendrites - ultrastructure; Disease Models, Animal; Hippocampus - enzymology; Hippocampus - physiopathology; Male; Nitrophenols - metabolism; Organophosphorus Compounds - metabolism; Phosphorylation; Pilocarpine - pharmacology; Prosencephalon - enzymology; Prosencephalon - physiopathology; Pyramidal Cells - cytology; Pyramidal Cells - enzymology; Rats; Rats, Sprague-Dawley; Status Epilepticus - chemically induced; Status Epilepticus - enzymology; Status Epilepticus - physiopathology; Synaptic Membranes - enzymology; Synaptosomes - enzymology; Up-Regulation - physiology
• ISSN: 0969-9961; 1095-953X
• DOI: 10.1016/j.nbd.2003.08.018

This study was performed to determine the effect of prolonged status epilepticus on the activity and subcellular location of a neuronally enriched, calcium-regulated enzyme, calcineurin. Brain fractions isolated from control animals and rats subjected to pilocarpine-induced status epilepticus were subjected to differential centrifugation. Specific subcellular fractions were tested for both calcineurin activity and enzyme content. Significant, status epilepticus-induced increases in calcineurin activity were found in homogenates, nuclear fractions, and crude synaptic membrane-enriched fractions isolated from both cortex and hippocampus. Additionally, significant increases in enzyme levels were observed in crude synaptic fractions as measured by Western analysis. Immunohistochemical studies revealed a status epilepticus-induced increase in calcineurin immunoreactivity in dendritic structures of pyramidal neurons of the hippocampus. The data demonstrate a status epilepticus-induced increase in calcineurin activity and concentration in the postsynaptic region of forebrain pyramidal neurons.