共查询到20条相似文献，搜索用时 18 毫秒
1.
Effect of glycine site/NMDA receptor antagonist MRZ2/576 on the conditioned place preference and locomotor activity induced by morphine in mice 总被引：3，自引：0，他引：3
Objective： To study the effect of glycine site/NMDA （N-methyl-D-aspartate） receptor antagonist MRZ2/576 on the conditioned place preference （CPP） and locomotor activity induced by morphine in mice. Methods： Different doses （1.25, 2.5 and 5 mg/kg, i.p.） of MRZ2/576 were used to evaluate the effect of MRZ2/576 on the acquisition and expression of CPP induced by morphine （5 mg/kg） in mice. In addition, we examined the locomotor activity of mice in conditioning and testing phase of CPP paradigm. Results： MRZ2/576 alone could not establish place preference, but a 5 mg/kg dose of MRZ2/576 could block both acquisition and expression of morphine-induced CPP. In testing phase of CPP, there was no statistical difference for locomotor activity between the groups; injection of MRZ2/576 showed a dose-dependent decrease of locomotor activity on both control and morphine-treated mice, especially 5 mg/kg of MRZ2/576 significantly suppressed the locomotor activity of mice. Conclusion： Based on the present results, we assume that MRZ2/576 can antagonize the rewarding effect of morphine, suggesting that this glycine site/NMDA receptor antagonist could be used to treat addictions due to its light side effect profile. 相似文献
2.
Jean S. Hendry 《Learning & behavior》1982,10(4):476-482
The effects of compounding two conditioned stimuli (CSs), each of which had been extinguished to varying degrees in different groups of rats given identical acquisition training, was examined within the conditioned emotional response paradigm. Greater suppression to the compound than to the individual CSs was observed following 6, 12, 48, 72, and 96 stimulus extinction trials, although after only 12 extinction trials suppression to the individual stimuli was no longer observed. The amount of compound suppression decreased progressively as the number of extinction trials increased until, after 120 extinction trials on each stimulus, the compound no longer elicited observable suppression. Control group data indicated that the observed summation effect could not be attributed to disinhibition. The possible role of the summation of undetected excitation in studies examining configurai conditioning, avoidance conditioning and reinstatement is discussed briefly. 相似文献
3.
Drugs of abuse have been reported to produce both rewarding and aversive effects, as evidenced by their ability to induce
both conditioned place preferences (CPPs) and conditioned taste aversions (CTAs), respectively. Although several attempts
have been made to assess the relationship between the rewarding and aversive effects of drugs in independent groups, it is
unknown to what extent (if any) preferences and aversions are related in individual animals. The present study assessed this
relationship by examining the ability of morphine (5 and 10 mg/kg) and amphetamine (3 and 5 mg/kg) to induce both place preferences
and taste aversions in the same animal, using a concurrent CTA/CPP design. There was no consistent relationship between the
ability of morphine or amphetamine at either dose to increase time spent on the drug-paired side and the ability to suppress
consumption of the drug-paired taste. These results support the position that drugs of abuse have multiple stimulus effects,
both rewarding and aversive, that condition place preferences and taste aversions independently. 相似文献
4.
Andrew R. Delamater 《Learning & behavior》1997,25(4):400-412
In two experiments, the possibility of outcome-selective reinstatement of conditioned responding was examined. Evidence for outcome-selective reinstatement of previously extinguished appetitively conditioned magazine responses by rats was observed in both Pavlovian (Experiment 1) and discriminated instrumental conditioning (Experiment 2) procedures. In both experiments, stimulus-elicited magazine responses occurred more in the presence of a stimulus whose reinforcer was reinstated than they did in the presence of another stimulus whose reinforcer was not reinstated. This effect was observed after both brief and extensive amounts of extinction. Outcome-selective reinstatement of instrumental leverpressing, however, was not observed, although nonselective reinstatement of magazine responding and leverpressing was obtained in Experiment 2. Overall, the data from these studies challenge existing theories of reinstatement, and they provide additional evidence of the importance of outcome-specific processes in the control of learned performance. 相似文献
5.
The attenuation of an LiCl-induced conditioned taste aversion (CTA) by LiCl preexposure is mediated primarily by associative blocking via injection-related cues. Given that preexposure to morphine attenuates morphine-induced CTAs, it was of interest to determine whether injection cues also mediate this effect. Certain morphine-induced behaviors such as analgesic tolerance are controlled associatively, via injection-related cues. Accordingly, animals in the present experiments were preexposed to morphine (or vehicle) every other day for five total exposures, followed by an extinction phase, in which the subjects were given saline injections (or no treatment) for 8 (Experiment 1) or 16 (Experiment 2) consecutive days. All of the animals then received five CTA trials with morphine (or vehicle). The morphine-preexposed animals in Experiment 1 displayed an attenuation of the morphine CTA that was unaffected by extinction saline injections, suggesting that blocking by injection cues during morphine preexposure does not mediate this effect. All of the morphine-preexposed subjects in Experiment 2 displayed a weakened preexposure effect, an effect inconsistent with a selective extinction of drug-associated stimuli. The attenuating effects of morphine preexposure in aversion learning are most likely controlled by nonassociative mechanisms, like drug tolerance. 相似文献
6.
In four experiments utilizing an appetitive conditioning preparation, reacquisition of conditioned responding was found to occur both rapidly and slowly following extinction. In Experiment 1, acquisition of responding to a tone that had been conditioned and extinguished occurred more rapidly than acquisition in either a group that received equivalent exposure to the food unconditioned stimulus or a “rest” control group that received only exposure to the apparatus in the first two phases. However, reacquisition was impaired relative to acquisition in a “learning-experienced” group that had previously received conditioning and extinction with a different stimulus. Experiments 2 and 3 produced similar results, but also found that high responding during reacquisition was confined to trials that followed reinforced, rather than nonreinforced, trials. Experiment 4, in which very few initial conditioning trials were used, produced reacquisition that was slow compared with both learning-experienced and rest controls. The results are consistent with a role for sequential learning: Reacquisition is rapid when animals have learned that reinforced trials signal other reinforced trials. 相似文献
7.
Mark E. Bouton 《Learning & behavior》1982,10(2):233-241
Three experiments with rat subjects were designed to investigate the possibility that an extinguished saccharin aversion might be reinstated if the animals are made ill with lithium chloride (in the absence of saccharin) following extinction. Although reinstatement can be obtained when the unconditioned stimulus is presented following the extinction of other kinds of conditioned behaviors, the present experiments provided no evidence that an extinguished taste aversion can be reinstated. No reinstatement was observed, even when the aversion had been only partially extinguished and when multiple injections of lithium chloride were administered in an attempt to reinstate the aversion. 相似文献
8.
Christopher L. Cunningham 《Learning & behavior》1979,7(1):45-52
A conditioned-emotional-response (CER) paradigm was used in two experiments to evaluate the effects of alcohol on extinction. In both experiments, rats received tone-shock pairings without alcohol and then received extinction trials either with or without alcohol (injections of saline, .75 or 1.5 g/kg ethanol). The high dose of alcohol suppressed baseline barpressing for food reward, but there was only weak evidence (Experiment 2) that it enhanced responding during the tone early in extinction. In both experiments, extinction of CER under the high alcohol dose was found to be state dependent, that is, post-extinction tests after saline injection showed a reinstatement of suppression to the tone. Experiment 2 indicated that this effect could be attributed to alcohol’s becoming a conditioned inhibitory stimulus as a result of its association with extinction. This supports the general suggestion that situational stimuli normally become inhibitory during the course of simple extinction and may have implications for the role that state-dependent learning plays in drug dependence. 相似文献
9.
Three experiments examined the effects of prior extinction with nontarget CSs on a target CS’s rate of extinction and amount of associative loss. After fear was conditioned to several CSs, rats received extinction training with the target CS either before or after extinction with nontarget CSs. In general, neither rate of extinction nor amount of associative change, as measured by reinstatement and relearning, were significantly affected by order of extinction. The present results do not support Rescorla’s interpretation of extinction. 相似文献
10.
Three experiments investigated the reinstatement of fear to a previously conditioned and extinguished CS as a result of separate presentation of the original US. That reinstatement was found to be sharply attenuated by nonreinforcement of a second fear elicitor between presentations of the US and testing of the CS. This “erasure” of reinstatement depended upon the fear-eliciting power of the intervening stimulus and, under some circumstances, was essentially complete. Moreover, erasure reduced not only the response to the CS but also the extinction it underwent as a result of subsequent nonreinforcement. It is argued that neither the conditioning of background stimuli nor stimulus generalization among explicit CSs provides an adequate account of these reinstatement and erasure results. Rather, they are interpreted in terms of the construction and destruction of a nonassociative representation of the US during conditioning, extinction, reinstatement, and erasure. In that context, some inferences can be made about the rules governing these nonassociative changes and the ways in which they interact with modifications in associations. 相似文献
11.
Pentobarbital is self-administered by rats but has also been reported to produce a conditioned place aversion. Since the self-administration and place preference paradigms both are considered to assess drug reward, we further examined the hedonic properties of pentobarbital, using place conditioning. In Experiment 1, a dose of 15 mg/kg (intraperitoneal) of pentobarbital produced a conditioned place aversion after 4 conditioning trials of various durations (5, 15, 30, or 60 min). Since rats are typically drug experienced in the self-administration paradigm, in Experiments 2 and 3, we examined the effect of drug history on pentobarbital-induced place conditioning. Although preexposure to pentobarbital attenuated the place aversion, it never resulted in a place preference. As has been reported with alcohol, pentobarbital is hedonically aversive in rats, when novel. 相似文献
12.
In five conditioned taste aversion experiments with rats, summation, retardation, and preference tests were used to assess the effects of extinguishing a conditioned saccharin aversion for three or nine trials. In Experiment 1, a summation test showed that saccharin aversion extinguished over nine trials reduced the aversion to a merely conditioned flavor (vinegar), whereas three saccharin extinction trials did not subsequently influence the vinegar aversion. Experiment 2 clarified that result, with unpaired controls equated on flavor exposure prior to testing; the results with those controls suggested that the flavor extinguished for nine trials produced generalization decrement during testing. In Experiment 3, the saccharin aversion reconditioned slowly after nine extinction trials, but not after three. Those results suggested the development of latent inhibition after more than three extinction trials. Preference tests comparing saccharin consumption with a concurrently available fluid (water in Experiment 4, saline in Experiment 5) showed that the preference for saccharin was greater after nine extinction trials than after three. However, saccharin preference after nine extinction trials was not greater, as compared with that for either latent inhibition controls (Experiments 4 and 5) or a control given equated exposures to saccharin and trained to drink saline at a high rate prior to testing (Experiment 5). Concerns about whether conditioned inhibition has been demonstrated in any flavor aversion procedure are discussed. Our findings help explain both successes and failures in demonstrating postextinction conditioned response recovery effects reported in the conditioned taste aversion literature, and they can be explained using a memory interference account. 相似文献
13.
Information was sought on how the strength of fear, acquired and extinguished in a classical conditioning paradigm, might be affected by certain of the circumstances that normally are associated with the course of avoidance learning. Following preconditioning exposures to the conditioned stimulus, one group of rats (Group PRF) was given continuous conditioned stimulus-unconditioned stimulus (CS-US) acquisition trials followed by stepwise reductions in US probability (given the CS) over three phases to about 11% for the final phase. Another group, Group US(lo), was given continuous CS-US pairings throughout, but, following acquisition, received stepwise reductions in US intensity (to permit evaluation of a progressively changing feature of the US over a wide range without having to employ excessive shock) over the same phases. A third group, Group US(hi), received unchanging (from acquisition) CS-US pairings over these phases, and an explicitly unpaired control group (Group RU) was included. Although outcomes differed somewhat depending upon whether suppression ratios or absolute measures of responding were considered, the major findings were that suppression to the CS was complete by the end of acquisition and persisted thereafter throughout the three phases for all but control subjects. In contrast to Group US(lo), which showed relatively little resistance to extinction of suppression to subsequent CS-only exposures, Groups US(hi) and PRF displayed marked resistance over two separate, extended sets of extinction sessions. Suppression to context cues was pronounced only for Groups US(hi) and RU, and varied as a function of US parameters and not whether the shocks were or were not signaled. Theoretical reconciliation of these findings was most difficult for Groun PRF. 相似文献
14.
Drugs of abuse have both rewarding and aversive effects, as indexed by the fact that they support place preferences and taste aversions, respectively. In the present study, we explored whether having a history with the aversive effects of morphine (via taste aversion conditioning) impacted the subsequent rewarding effects of morphine, as measured in the place preference design. In Experiment 1, rats were exposed to a taste aversion procedure in which saccharin was followed by morphine. Place preference conditioning was then initiated in which animals were injected with morphine and placed on one side of a two-chambered apparatus. Animals with a taste aversion history acquired place preferences to the same degree as controls without such a history, suggesting that morphine’s affective properties condition multiple effects, dependent on the specific stimuli present during conditioning. To determine whether these results were a reflection of processes operating in traditional associative conditioning, in a modified blocking procedure, place preference conditioning was attempted in the presence of a taste previously associated with morphine (Exp. 2). Under these conditions, animals still acquired morphine-induced place preferences comparable to those of animals without a morphine or conditioning history. These results are consistent with the position that drugs of abuse have multiple stimulus effects (positive and negative) that are differentially associated with specific stimuli (environmental and taste) that drive different behavioral responses (approach and avoidance). 相似文献
15.
Water-deprived rats were given a single exposure to saccharin and LiCl, either paired or unpaired. Half the subjects then received three saccharin-only exposures (extinction) in the training enclosure, followed by a single LiCl-only presentation (unconditioned stimulus reinstatement) 8 days after conditioning. The remaining subjects received six saccharin-only exposures, followed by LiCl reinstatement 13 days after conditioning. In both cases LiCl reinstatement occurred outside the training/test context. Appreciable recovery from extinction was observed after the partial loss of taste aversion obtained with three extinction sessions and the 8-day conditioning-reinstatement interval, but not after the asymptotic loss of taste aversion obtained with six extinction sessions and the 13-day conditioning-reinstatement interval. Conditioned taste aversions appear to be similar to more traditional associations with respect to both extinction and reinstatement-induced recovery from extinction. The results are discussed with reference to the event-memory, contextual-conditioning, and facilitated-retrieval hypotheses of postextinction reinstatement effects. 相似文献
16.
Chana K. Akins 《Learning & behavior》1998,26(4):416-426
Three experiments were conducted to investigate direct and modulatory influences of context in the conditioned sexual behavior of male Japanese quail. A preference test procedure was used to assess the acquisition of contextual excitation. In Experiment 1, following direct context-unconditioned stimulus (US) pairings, male quail shifted their contextual preference from an initially preferred context to one in which they received copulatory opportunity with a female quail (US). Unpaired control group subjects did not demonstrate this shift in preference. This place preference procedure was used in Experiments 2 and 3 to assess contextual excitation when context was trained in the presence of a discrete conditioned stimulus (CS). Experiment 2 provided evidence that context can modulate responding to a discrete CS. In Experiment 3, we varied the spatial contiguity between the context and the US. Some subjects received the US directly in the training context, whereas other subjects received the US in an alternate context. Contextual excitation was evident only in subjects that received the former. Thus, there is a dissociation between the modulatory and excitatory properties of context in sexual conditioning that may depend on the context-US spatial contiguity. 相似文献
17.
Three experiments demonstrated that, following the extinction of an established conditioned stimulus (CSA—e.g., tone), the
pairing of a novel, cross-modal stimulus (CSB—e.g., light) with the unconditioned stimulus (US) results in strong recovery
of responding to the extinguished CSA. Experiment 1 demonstrated that the recovery of responding to CSA is not the result
of US reinstatement but is attributable to pairings of CSB with the US. Experiment 2 demonstrated that the recovery of responding
is specific to CSA and is not the result of cross-modal generalization. Experiment 3 revealed that a large number of CSB-US
pairings in Stage 1 significantly reduced the amount of recovery to CSA during subsequent CSB-US trials. Experiment 3 also
provided unexpected evidence of cross-modal secondary extinction. The extinction and subsequent recovery of responding seen
in the present experiments is discussed with respect to possible contributions from contextual associations, CS processing,
US processing, conditioned response expression, and layered excitatory associations. 相似文献
18.
M. J. Homzie 《Learning & behavior》1974,2(1):77-79
Following a 47-day extinction procedure, the reinstatement of the cue previously associated with reward produced an immediate improvement in performance. The cue was the opportunity to traverse the alley following an “anticipated” nonrewarded runway trial. Moreover, the animals trained in this matter exhibited daily increments in performance during the initial phase of extinction testing. The results were interpreted as consistent with the notion that the difference in extinction performance of one group as compared to another does not necessarily reflect the relative “strengths” of the instrumentally acquired habits. Instead, it probably indicates the degree of similarity of the extinction testing procedure to the acquisition training condition previously associated with reinforcement for the two individual groups. 相似文献
19.
Previous place conditioning studies in mice have shown that injection of ethanol immediately before a conditioned stimulus (CS+) produces conditioned preference, whereas injection of ethanol immediately after CS+ produces conditioned aversion. In the present experiments, we examined the learning that occurs when ethanol is injected in “ambiguous“ procedures that provide the opportunity for both types of conditioning. When ethanol was given midway through the CS (Experiments 1 and 2) or both before and after the CS (Experiment 3), the direction of place conditioning was the same as when mice were exposed only to whichever contingency occurred first (a primacy effect). That is, injection of ethanol in the middle of the CS conditioned aversion, whereas injection both before and after the CS conditioned preference. Because these results support the idea that ethanol elicits both aversive and rewarding effects, they are most consistent with conditioning theories that conceptualize unconditioned stimuli (USs) as events that can activate multiple representational components. 相似文献
20.
We conducted three experiments to investigate the associative structure underlying the reinstatement of instrumental performance
after extinction. In each experiment, rats were initially rewarded on two responses with different outcomes. At test, both
responses were extinguished in order to assess the impact of a single noncontingent outcome delivery on response selection.
Experiment 1 found evidence of outcome-selective reinstatement (i.e., more responses were performed on the lever that was
trained with the reinstating outcome than on the other lever). Experiment 2 demonstrated that the outcome’s capacity to reinstate
performance was not affected by a reduction in its motivational value. Experiment 3 found evidence that the reinstating outcome
selectively retrieved the response it signaled rather than the response it followed during training. Together, these findings
are consistent with the view that instrumental reinstatement depends on the discriminative stimulus properties of the reinstating
outcome. 相似文献