caa a22 4500 469119748 CHVBK 20180323133135.0 cr unu---uuuuu 170328e19920701xx s 000 0 eng 10.1007/BF02245283 doi (NATIONALLICENCE)springer-10.1007/BF02245283 The acoustic startle response as a measure of behavioral dependence in rats [Elektronische Daten] [Robert Mansbach, Lisa Gold, Louis Harris] A series of experiments was conducted to assess the sensitivity of the acoustic startle response to chronic morphine administration and naloxone-precipitated withdrawal. Rats were implanted with two subcutaneous pellets containing either 75 mg each of morphine or containing only placebo. In experiment 1, withdrawal induced by 0.05-0.2 mg/kg naloxone dose-dependently decreased the magnitude of the startle response. Physical dependence was confirmed by a naloxone-induced acute weight loss seen in morphine-implanted rats, but naloxone had no effect on startle or body weight in nondependent animals. In experiment 2, a modified procedure with fewer trials per session and fewer test days was employed. Naloxone (0.2 mg/kg) given 4-5 days after implantation induced large startle-response decreases in morphine-dependent rats while having no effect in placebo-implanted rats. Post-naloxone saline tests revealed no significant differences in startle between morphine and placebo groups. Startle scores were significantly higher in morphine-implanted rats than in placebo rats during a saline test given 3 days following pellet implantation. In a separate group of animals, however, acute IP injections of morphine from 0.3-10 mg/kg had no significant effect on startle amplitude. The effect of repeated pairings of withdrawal with the startle environment was assessed in experiment 3. Morphine-dependent rats startled significantly less if naloxone injections were given before the startle session than if they were administered 4 h later. Conditioned withdrawal effects, expressed during a final test session when all rats received saline, were observed for the body-weight measure but not for the startle response. These results suggest that the acoustic startle response may be a useful objective measure in evaluating physical dependence produced by substances of abuse. Springer-Verlag, 1992 Physical dependence nationallicence Acoustic startle response nationallicence Withdrawal nationallicence Morphine nationallicence Naloxone nationallicence Rat nationallicence Mansbach Robert Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, 23298-0613, Richmond, VA, USA aut Gold Lisa Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, 23298-0613, Richmond, VA, USA aut Harris Louis Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, 23298-0613, Richmond, VA, USA aut Psychopharmacology Springer-Verlag 108/1-2(1992-07-01), 40-46 0033-3158 108:1-2<40 1992 108 213 https://doi.org/10.1007/BF02245283 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02245283 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mansbach Robert Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, 23298-0613, Richmond, VA, USA aut NATIONALLICENCE 700 1- Gold Lisa Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, 23298-0613, Richmond, VA, USA aut NATIONALLICENCE 700 1- Harris Louis Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, 23298-0613, Richmond, VA, USA aut NATIONALLICENCE 773 0- Psychopharmacology Springer-Verlag 108/1-2(1992-07-01), 40-46 0033-3158 108:1-2<40 1992 108 213 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer