Active control and its stress effects.
The effects of 5-fold injections of normal saline were studied in Wistar rats in two conditioned reflex situations: defense and alimentary. Intact animals developed conditioned pain avoidance reflex in repeated tail-flick test after 60 presentations over 3 days. Two injections of normal saline were sufficient for the formation of a stable negative stress status in experimental rats, which manifested by a drastic increase in tactile sensitivity persisting for 5 days after discontinuation of injections. Only 15% experimental rats vs. 40% intact animals developed the food-procuring response in a multialternative maze. Presumably, repeated injections of normal saline should be regarded as a potent negative stress factor modulating animals behavior, and these signs should be taken into consideration, when interpreting the effects observed in pharmacological investigations.
Kondashevskaya
M V
MV
Group for Investigation of Functional Morphology of Stress, Institute of Human Morphology, Russian Academy of Medical Sciences. mariluka@mail.ru
Nikol'skaya
K A
KA
D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology*; D007274:Injections, Intraperitoneal / Q000009:adverse effects; D008297:Male; D018782:Maze Learning; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000008:administration & dosage; D013312:Stress, Physiological / Q000503:physiopathology*
D012965:Sodium Chloride