Influence of extremely low frequency magnetic fields on Ca2+ signaling and NMDA receptor functions in rat hippocampus.
Extremely low frequency (ELF<300Hz) electromagnetic fields affect several neuronal activities including memory. Because ELF magnetic fields cause altered Ca(2+) homeostasis in neural tissues, we examined their influence on Ca(2+) signaling enzymes in hippocampus and related them with NMDA receptor functions. Hippocampal regions were obtained from brains of 21-day-old rats that were exposed for 90 days to 50Hz magnetic fields at 50 and 100 microT intensities. In comparison to controls, ELF exposure caused increased intracellular Ca(2+) levels concomitant with increased activities of Ca(2+)-dependent protein kinase C (PKC), cAMP-dependent protein kinase and calcineurin as well as decreased activity of Ca(2+)-calmodulin-dependent protein kinase in hippocampal regions. Simultaneous ligand-binding studies revealed decreased binding to N-methyl-D-aspartic acid (NMDA) receptors. The combined results suggest that perturbed neuronal functions caused by ELF exposure may involve altered Ca(2+) signaling events contributing to aberrant NMDA receptor activities.
Manikonda
Pavan K
PK
Department of Biochemistry, Osmania University, Hyderabad 500007, India.
Rajendra
P
P
Devendranath
D
D
Gunasekaran
B
B
Channakeshava
Aradhya
R S S
RS
Sashidhar
R B
RB
Subramanyam
C
C
D000818:Animals; D001667:Binding, Competitive / Q000502:physiology / Q000528:radiation effects; D019703:Calcineurin; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology / Q000528:radiation effects*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism / Q000528:radiation effects; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism / Q000528:radiation effects; D004574:Electromagnetic Fields / Q000009:adverse effects*; D018698:Glutamic Acid / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism / Q000503:physiopathology / Q000528:radiation effects*; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D011493:Protein Kinase C / Q000378:metabolism / Q000528:radiation effects; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism / Q000528:radiation effects*; D009435:Synaptic Transmission / Q000502:physiology / Q000528:radiation effects
D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019703:Calcineurin; D002118:Calcium