Benzodiazepine anti-conflict effects in Maudsley reactive (MR/Har) and non-reactive (MNRA/Har) rats.
The Maudsley Reactive (MR/Har) and Non-Reactive (MNRA/Har) rat strains, bred originally by Broadhurst for differences in Open Field Defecation, also differ in their control (i.e., non-drug) behavior in the Conditioned Suppression of Drinking (CSD) conflict procedure, a second "model" behavior for the study of anxiety and/or emotionality in rats. The present studies compared the effects of diazepam and alprazolam on CSD behavior in these two strains of rats. In daily 10-min sessions, water-deprived rats were trained to drink from a tube that was occasionally electrified (0.2-0.5 mA), electrification being signaled by a tone. Both diazepam and alprazolam increased punished responding in a dose-related manner. The per cent increase in punished responding (for diazepam only) was comparable in the two strains; however, both statistical and empirical approaches indicated that the magnitude of the anti-conflict effect of benzodiazepines in MNRA/Har versus MR/Har rats was not related to differences in baseline (i.e., non-drug) punished responding. Based on the absolute change in shocks received, rats of the MNRA/Har strain exhibited a significantly greater anti-conflict effect following diazepam or alprazolam treatment than did rats of the MR/Har strain. These findings further the hypothesis that the behavioral differences exhibited by Maudsley MR/Har and MNRA/Har rat strains may constitute a genetically-based "animal model" for the study of emotionality and/or anxiety.
Commissaris
R L
RL
Department of Pharmaceutical Sciences, College of Pharmacy & AHP, Detroit, MI.
Harrington
G M
GM
Altman
H J
HJ
D000525:Alprazolam / Q000494:pharmacology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001362:Avoidance Learning / Q000187:drug effects; D003220:Conflict, Psychological; D003672:Defecation / Q000187:drug effects; D004597:Electroshock; D005260:Female; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D014151:Anti-Anxiety Agents; D000525:Alprazolam