Physiol. Res. 53: 343-349, 2004


Changes in the Number of Nitrergic Neurons Following Kainic Acid Administration and Repeated Long-term Hypoxia

P. BENEŠOVÁ1,2, M. LANGMEIER1, J. BETKA2, S. TROJAN1

1Institute of Physiology and 2Department of Otorhinolaryngology and Head and Neck Surgery, First Faculty of Medicine, Charles University, Prague, Czech Republic

Received July 4, 2003
Accepted August 12, 2003



Summary
Using histochemical analysis (NADPH-diaphorase) we have been investigating the influence of intraperitoneal administration of kainic acid (KA), hypoxia and combination of both these factors on neurons of the hippocampus and on the primary auditory cortex (PAC) in male rats of the Wistar strain. Kainic acid was administered to 18-day-old animals, which were exposed to long-lasting repeated hypoxia from the 2nd till the 17th day of age in a hypobaric chamber (for 8 h a day). At the age of 22 or 90 days, the animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anesthesia. Cryostate sections were stained to identify NADPH-diaphorase positive neurons that were then quantified in the hippocampus, in the dentate gyrus and in the PAC. In 22-day-old animals both hypoxia and KA increased the number of NADPH-diaphorase positive neurons in the hilus, CA1, CA3 areas of the hippocampus and in the PAC. On the contrary, KA given to hypoxic animals lowered the number of NADPH-diaphorase positive neurons in the dentate gyrus. In 90-day-old animals, hypoxia and KA given to both normoxic and hypoxic animals lowered the number of NADPH-diaphorase positive neurons in some areas of the central nervous system.


Key words
Kainic Acid • Nitric Oxide • Hypoxia • Hippocampus • Primary auditory cortex
 


© 2004 by the Institute of Physiology, Czech Academy of Sciences