Behavioral sensitization and tolerance to the D2 agonist RU 24213: dissociation between several behavior patterns in mice.
Previous studies have shown that different components of behavioral effects of indirect agonists given chronically to laboratory rodents can follow different courses during treatment. Whether repeated injections of a D2 agonist can lead to the same phenomenon was investigated in mice using the D2 agonist N-n-propyl-N-phenylethyl-p-(3-hydroxy-phenyl)-ethylamine (RU 24213). Five mutually exclusive behaviors were examined over seven intermittent administrations (every other day over 13 daily injections) of RU 24213 (2.5 mg/kg SC) in mice. Rapid tolerance to the clearest initial effect of RU 24213, stillness, was found. Suppression of grooming also showed tolerance later in the treatment regimen (from the fourth test). From the third test, parallel time courses of sensitization were obtained for ambulation and rearing. Sleeping position was strongly depressed throughout the chronic treatment. These results show that the development in time of the behavioral effects of RU 24213 injected chronically strongly depend upon the behavioral measure. This supports the use of multiple measures in the same animal in the behavioral analysis of chronically injected dopaminergic drugs.
Tirelli
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E
Laboratoire de Psychologie Expérimentale, Université de Liége au Sart-Tilman, Belgium.
Jodogne
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C
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015259:Dopamine Agents / Q000494:pharmacology*; D004361:Drug Tolerance; D006120:Grooming / Q000187:drug effects; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D010627:Phenethylamines / Q000494:pharmacology*; D011187:Posture / Q000502:physiology; D017448:Receptors, Dopamine D2 / Q000187:drug effects*; D012726:Sexual Behavior, Animal / Q000187:drug effects*
D015259:Dopamine Agents; D010627:Phenethylamines; D017448:Receptors, Dopamine D2; C016868:N-n-propyl-N-phenylethyl-4(3-hydroxyphenyl)ethylamine hydrochloride