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Biomedical subjects

I P Stolerman

Publications and source records attributed to I P Stolerman.

At least 127 records · Page 7Linked to original sources

Conditioned flavor aversions for assessing precipitated morphine abstinence in rats.

Rats receiving twice-daily morphine injections acquired aversions to a saccharin solution which had been presented for 1 hr immediately prior to injections of naloxone. The degree of aversion was related to the maintenance dosage of morphine. Rats maintained on a regimen of daily saline injections did not show significant aversion to saccharin paired with naloxone, even at doses as high as 40 mg/kg. The sensitivity of the technique was such that significant aversions could be demonstrated in rats receiving doses of morphine as low as 1 mg/kg twice daily. It is suggested that conditioned flavor aversions provide a useful method for assessing the aversive quality of abstinence precipitated from low doses of morphine.

Animals↗

Weight loss and shock-elicited aggression as indices of morphine abstinence in rats.

Weight loss and shock-elicited aggression have been compared as quantitative indices of morphine abstinence in rats. A range of doses of morphine was administered to rats by i.p. injection twice daily for 12-15 days. After injections were stopped, morphine-abstinent rats lost weight precipitously, and showed an increased frequency of fighting in response to aversive stimulation (foot-shock). Recovery of weight appeared complete after 15-20 days but a significant increase in aggression was found at 18 days post-withdrawal; this virtually disappeared after 52 days. Both the amount of weight lost and the frequency of fighting increased as a function of the previous maintenance dose of morphine; the effective dose range appeared similar for these two indices. Weight loss was much less variable than fighting, had the advantage of rapid, objective measurement, and appeared to be the more reliable index of abstinence.

Aggression↗

Disturbed patterns of behaviour in morphine tolerant and abstinent rats.

1. Eating, drinking and spontaneous motor activity were studied in rats receiving large daily doses of morphine. These forms of behaviour were largely suppressed when the rats were made abstinent and were restored when morphine was given again.2. Compensation for depressions of behaviour during abstinence did not seem sufficient to account for all the stimulant effects of morphine in tolerant rats. Morphine also had slight stimulant actions in non-tolerant rats.3. In tolerant rats, the repeated pairing of the effects of morphine with the re-emergence of behaviour such as eating and drinking may intensify the rewarding value of the drug.

Animals↗