Conditioned preferences in the rat with an unnatural need state: Morphine withdrawal.

Abstract

Morphine addicted and nonaddicted rats were placed on a 21-day conditioning regimen which involved the daily alternation of access to either water, sucrose-octa-acetate (SOA), or no liquid for 1 hr. The addicted rats received injections of morphine after either the SOA sessions or the no-liquid sessions. The nonaddicted rats were injected with morphine after the SOA sessions. Following the last injection the animals were given a two-bottle preference test between SOA and water. The results showed that the addicted animals that received morphine-SOA pairings had an increased preference for SOA, whereas the nonaddicted animals showed a decrease in SOA preference after the same conditioning treatments. The addicted rats that received the morphine injections on the no-liquid days showed no change in SOA preference.If a rat is allowed to consume a novel substance and is subsequently made ill, the rat will associate the flavor of the substance with the postingestional stress and avoid consuming the substance thereafter (Garcia, Ervin, & Koelling, 1967a; Revusky & Garcia, 1970). A logical counterpart to the conditioning of aversions by toxicosis would be the conditioning of increases in preference for flavors that are followed by beneficial postingestional effects. By comparison with conditioned aversions, however, the reported effects of beneficial postingestinal consequences have been small and rather difficult to obtain (Revusky & Garcia, 1970;Rozin & Kalat, 1971).Garcia, Ervin, Yorke, and Koelling (1967b) conditioned increases in preference for saccharin solutions in thiamine-deficient rats by pairing thiamine injections with the consumption of the flavored solutions. Zahorik and Maier (1969), using thiamine deficiency as the relevant need state, extended

Morphine-induced taste aversions: A consideration of parameters

“…This differential activation of the pituitary-adrenal system may provide some basis for the findings in the present report as well as providing some support for the notion of a general physiological mechanism underlying conditioned taste aversions (Braveman, 1977;Riley et al, 1976). Coussens et al , 1973;Farber et al ., 1976;Goudie et al, 1976;Jacquet, 1973;Parker et al, 1973), these data are in sharp contrast to the aversions typically induced by emetic USs. Lithium chloride, for example, produces strong aversions after only one trial (Nachman & Ashe, 1973;Nachman & Hartley, 1975) and complete aversions when repeated trials are given (Fenwick et al, 1975;Riley et al, 1976).…”

“…Although a number of researchers have found morphine to be an effective US in conditioning aversions (Amit, Levitan, Brown, & Rogan, in press;Cappell & LeBlanc, 1977;Cappell, LeBlanc, & Endrenyi, 1973;Cappell, LeBlanc, & Herling, 1975;Coussens, 1974;Farber, Gorman, & Reid, 1976;Goudie, Thornton, & Wheeler, 1976;Jacquet, 1973;LeBlanc & Cappell, 1974Parker, Failor, & Weidman, 1973;Sklar & Amit, in press;White et al, 1977), morphine-induced aversions often take more than one trial to develop (Berger, 1972;Cappell & LeBlanc, 1977;Coussens, Crowder, & Davis, 1973;Farber et al, 1976; and are typically incomplete even after repeated conditioning trials (Cappell et al, 1973;Farber et al, 1976;Goudie et al, 1976;Jacquet, 1973;Parker et al, 1973). The acquisition and strength of morphineinduced aversions are in marked contrast to aversions established by emetics.…”

Restricted role of CRF1 receptor for the activity of brainstem catecholaminergic neurons in the negative state of morphine withdrawal

“…In this study, withdrawal was precipitated by naloxone in morphinetreated wild-type or CRF1R-deficient mice and changes in body weight were assessed. Withdrawal can be conditioned to the discontinuation of treatment (Parker et al 1973); however, the current study used antagonist-precipitated withdrawal for conditioning because more robust withdrawal signs were observed following naloxone administration than following discontinuation of treatment and because acute withdrawal occurs more reliably when it is precipitated by an antagonist. Our data indicate a weight loss, one objective and accurate measurable sign of opioid withdrawal, after naloxone-induced withdrawal in wildtype morphine-treated mice; the weight loss in morphine withdrawn CRF1R −/− animals was significantly attenuated.…”

Affective consequences and subsequent effects on morphine self-administration of d-ala2-methionine enkephalin

“…The experiment used the now classical taste aversion paradigm (Garcia, Hankins, & Rusiniak, 1974;Riley & Baril, 1976). It has been shown that morphine, when used as the unconditioned stimulus, can sustain a poison aversion (LeBlanc & Cappell, 1974;Parker, Failor, & Weidman, 1973), but the resultant poison aversion is less intense than those sustained by unequivocally toxic agents (Gorman et al, 1978;Riley, Jacobs, & Lolordo, 1978). The taste aversion paradigm is theoretically sensitive to the ability of an agent to produce nausea and, combined with results indexing the possibility for an agent to elicit positive effect, can be used to determine if an agent produces negative effects or mixed affective events.…”