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
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