Stress-induced behaviour in juvenile rats: effects of neonatal asphyxia, body temperature and chelation of iron.
Newborn mammals, showing reduced normal body temperature, might be protected against iron-mediated, delayed neurotoxicity of perinatal asphyxia. Therefore, we investigated the effects of (1) neonatal body temperature and neonatal critical anoxia as well as (2) postanoxic chelation of iron with deferoxamine, on open-field stress-induced behaviour in juvenile rats. The third aim of this study was to compare (after the above-mentioned treatments) circadian changes in spontaneous motor activity and body temperature in juvenile rats permanently protected from any stress. Neonatal anoxia at body temperature adjusted (both during anoxia and 2 h reoxygenation) to a level typical of healthy (37 degrees C) or febrile (39 degrees C) adults led to the stress-induced hyperactivity in juvenile (5-45 days old) rats. Both normal neonatal body temperature of 33 degrees C and chelation of iron prevented the hyperactivity in rats. Neither neonatal body temperature nor neonatal anoxia affected spontaneous motor activity or body temperature of juvenile rats, recorded in their home-cages with implantable transmitters. Circadian rhythmicity was also undisturbed. Presented data support the hypothesis that physiologically reduced neonatal body temperature can provide a protection against iron-mediated postanoxic disturbances of behavioural stress responses in juvenile rats.
Department of Animal Physiology, Institute of General and Molecular Biology, N. Copernicus University, ul. Gagarina 9, 87-100 Toruń, Poland. rogal@biol.uni.torun.pl
Justyna
J
Rogalska
Michał
M
Caputa
Katarzyna
K
Wentowska
Anna
A
Nowakowska
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001237:Asphyxia / Q000209:etiology*; D001522:Behavior, Animal; D001831:Body Temperature / Q000502:physiology*; D003676:Deferoxamine / Q000494:pharmacology; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology; D007501:Iron / Q000378:metabolism*; D007502:Iron Chelating Agents / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological / Q000378:metabolism / Q000503:physiopathology*; D013686:Telemetry / Q000295:instrumentation; D013997:Time Factors
D007502:Iron Chelating Agents; D007501:Iron; D003676:Deferoxamine