摘要:

AbstractSystematic research on the stimulus properties of drugs began about 25 years ago. Informal discussion groups and scientific meetings contributed a great deal to developing this area of research into a scientific discipline. A brief history of these discussions and meetings is described.

ISSN:0272-4391    

DOI:10.1002/ddr.430160203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThere have been few comparisons between different schedules of reinforcement for establishing drugs as discriminative stimuli. Fixed‐ratio (FR‐10) and tandem variable‐interval 1‐min FR‐10 schedules have, therefore, been compared directly in a conventional, drug‐saline discrimination paradigm with food reinforcement in rats. The drug used for training was nicotine (0.4 mg/kg s.c., “faded” to 0.1 mg/kg s.c.). The discrimination was acquired rapidly under both schedules, with stimulus control by nicotine being slightly superior under the FR‐10 schedule. In 5‐min extinction tests with nicotine, the FR‐10 schedule gave a clear dose‐response curve with a bar‐selection (quantal) index but with generally poor results when the percentage of drug‐appropriate responding (quantitative index) was calculated. In contrast, the tandem schedule yielded clear dose‐response data with both indices. In tests with (+)‐amphetamine, full generalization was obtained with both FR‐10 and tandem schedules and with both quantitative and quantal indices. Tests for generalization to morphine were negative regardless of the training schedule. The results confirm that orderly data may be obtained with either an FR‐10 or a tandem schedule provided that an appropriate index of discriminative response is employed. The results generally support the validity of current practices, and there will probably not be very marked differences between conclusions

ISSN:0272-4391    

DOI:10.1002/ddr.430160204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractData are summarized which indicate that drug discriminative stimuli (DDS) and exteroceptive, sensory stimuli interact in a systematic manner. Thus recent work revealed that phenomena such as overshadowing, blocking, and conditional discrimination are operable in drug discrimination learning (DDL) experiments involving exteroceptive cues and DDS. Additionally, in a reversal learning experiment, a contextual change differentially affected rate of reversal learning and subsequent generalization test data.

ISSN:0272-4391    

DOI:10.1002/ddr.430160205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThis study involved an attempt to develop a screening test to select animals that would learn a cocaine drug discrimination (DD) rapidly and an analysis of factors affecting rates of acquisition of cocaine DD. Rats (n = 18) were trained initially in a conditioned taste aversion (C.T.A.) procedure with cocaine (36 mg/kg). Subjects were then trained to discriminate cocaine (5 mg/kg) in an operant procedure, and the cocaine generalization curve was determined. Subjects were then tested for cocaine‐induced hyperthermia. Animals that showed weak C.T.A. showed relatively rapid acquisition of DD (rs= –0.56,P>0.05, two tailed). Cocaine‐induced hyperthermia did not predict speed of acquisition reliably, nor did cocaine's effects on operant responding. Animals were allocated retrospectively to groups of “rapid” and “slow” discriminators. These groups did not differ in generalization ED50s, in sensitivity to cocaine's effects on operant responding, or in hyperthermic responses to cocaine. Thus speed of DD acquisition was not dependent on individual sensitivity to cocaine. Furthermore, “rapid” and “slow” discriminators probably cannot be dissociated in terms of learning ability, since animals that acquired marked C.T.A. showed slow learning of DD. The C.T.A. data suggest that animals sensitive to dysphoric effects of cocaine are less sensitive to the drug's cueing properties and thus that the cocaine cue at 5 mg/kg may be related to its euphoriant actions. It is possible that C.T.A. procedures can be used to select animals that will lea

ISSN:0272-4391    

DOI:10.1002/ddr.430160206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractConditioned responses to amphetamine treatment at three doses were investigated with the “conditioned emotional response” paradigm, in which an auditory‐visual stimulus was presented 3 min before i.p. drug injection to rats lever pressing for food pellets. Conditioned responses to this preinjection stimulus were indicated by changes from baseline response rate during each of eight conditioning sessions and after water injections (again preceded by the A‐V stimulus) on a final extinction‐test day. In experiment 1, the reinforcement schedule was tandem VI‐30 sec/FR4, and the amphetamine dose was 3.0 mg/kg, which produced nearly complete response suppression by the end of the 20‐min postinjection period. Suppression to the preinjection CS was seen after two conditioning sessions, and marked condition suppression also occurred after water injection on the test day. In a second experiment, using additional animals, the reinforcement schedule was VI‐60 sec, and two drugged groups were used to determine lower‐dose amphetamine effects. Significant preinjection suppression (of a lesser degree than seen in experiment 1) developed after six conditioning sessions with amphetamine 1.5, but not 0.8 mg/kg. Similar dose differences were seen in the postinjection‐conditioned responses. These results provide dose‐response information on conditioned responses to a CNS stimulant in the conditioned

ISSN:0272-4391    

DOI:10.1002/ddr.430160207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe present study was designed to examine the disruptive effects of reinforcement during stimulus onset/offset in drug‐discrimination tasks. Rats were trained on a two‐lever task to discriminate either pentylenetetrazole (PTZ, 20 mg/kg) or cocaine (CN, 10 mg/kg) from saline, with food used as a reinforcer. Tests for onset of the drug stimulus were conducted immediately after an i.p. injection of the training stimulus. In order to test drug offset, rats trained to discriminate PTZ were tested immediately after an injection of diazepam (DZP, 5 mg/kg) given 15 min after an injection of PTZ. Responses on either lever were reinforced throughout the 20‐min session. Although the onset or offset of a drug stimulus significantly changed lever selection, consistent change in lever selection was obtained from approximately 30% of the subjects. For both the CN and PTZ onset groups, lever changing occurred after either (1) a disruption in responding, which produced a period of no reinforcement, or (2) very early in the session, which provided only brief exposure to reinforcement for responding on the other lever. Drug‐induced disruption of behavior was much more apparent during PTZ onset than during CN onset. For animals that continued to be reinforced for nondrug responding after onset of the drug stimulus, discrimination of the training stimulus during subsequent training was not disrupted by the testing pr

ISSN:0272-4391    

DOI:10.1002/ddr.430160208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThree separate drug‐discrimination experiments, using pigeon subjects, were designed to assess the modification of a morphine (MS) stimulus by d‐amphetamine (AMPH). Experiment 1 examined the drug mixture in a two‐choice discriminative procedure in three groups of subjects trained to one of three doses of MS (1.0, 3.2, or 10 mg/kg) vs. saline (SAL). Blockade of the MS stimulus by concomitant AMPH administration was training dose‐dependent. Complete blockade was found in the high‐MS (10 mg/kg) training dose (TD) group; partial blockade was found in the intermediate‐TD (3.2 mg/kg) group; and complete generalization was found in the low‐TD (1.0 mg/kg) group. Experiment 2 was designed to assess whether the MS‐AMPH mixture resulted in the creation of a functionally new stimulus. With a three‐choice drug‐discrimination procedure, two new groups were trained to discriminate between 3.2 mg/kg MS, SAL, and 1.8 mg/kg AMPH. Once training criteria were met, subjects were divided into two groups and one group's MS training dose was faded up to 10 mg/kg. Data clearly indicated that MS‐AMPH combinations did not produce novel stimuli. Experiment 3 was designed to assess the MS‐AMPH combinations in a three‐choice quantitative discrimination using 1.8 mg/kg MS vs. SAL vs. 10 mg/kg MS as discriminative stimuli. Data suggested that if masking does occur, it is a result of shifting the dose‐response function to the left (i.e., to a nondiscriminable dose). We conclude that perceptual masking of drug stimuli can occur, but the phenomenon seems dependent on training dose and/or

ISSN:0272-4391    

DOI:10.1002/ddr.430160209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractAs reported by Gauvin and Young [1987], a robust discrimination can be established among saline, 10 mg/kg morphine, and 1.8 mg/kg morphine. The present experiment further examined the pharmacological characteristics of this discrimination. Pigeons were trained to discriminate among i.m. injections of saline, 1.8 mg/kg morphine (the low‐dose, or LD, stimulus), and 10 mg/kg morphine (the high‐dose, or HD, stimulus). Performance was maintained under FR 30 schedules of food delivery in 30‐min experimental sessions. After establishment of stimulus control, various doses of morphine, the agonist‐antagonist nalbuphine, and the nonopioid pentobarbital were tested for generalization to the LD and HD stimuli. For morphine itself, generalization of the LD and HD stimuli varied as a function of dose. A dose of 0.10 mg/kg morphien occasioned responses to only the saline key. As the dose of morphine was increased to 1.8 mg/kg, the proportion of responses to the LD key increased from 0 to 100%. As the dose was increased further, the proportion of responses to the LD key decreased, with a commensurate increase in responses to the HD key. Complete HD generalization occurred at 5.6 or 10 mg/kg morphine. In contrast, the opioid agonist‐antagonist nalbuphine (1.0 to 56 mg/kg) evoked generalization to only the LD stimulus. The highest dose of nalbuphine markedly suppressed response rates. The nonopioid pentobarbital (0.1 to 18 mg/kg) evoked neither LD nor HD generalization. This pattern of generalization suggests that the discrimination among saline and two doses of morphine may provide a fruitful assay for the agonist efficacy of nove

ISSN:0272-4391    

DOI:10.1002/ddr.430160210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractIn pigeons trained to discriminate 5.6 mg/kg of morphine from saline, cyclazocine, l‐N‐allyl‐normetazocine (l‐NANM, l‐SKF10,047), and ketamine, but not U50,488, produced partial generalization, i.e., a maximum level of drug‐appropriate responding between the levels produced by saline and by the training drug. The generalization gradient of cyclazocine and of l‐NANM, but not that of ketamine, was less steep than the gradient of morphine. Cyclazocine and l‐NANM, but not U50,488 and ketamine, antagonized partially the discriminative stimulus (DS) effects of morphine. Naltrexone antagonized the DS effects of morphine, cyclazocine, and l‐NANM, but not ketamine. Increasing the training dose of morphine shifted the morphine gradient to the right, increased the antagonist effects of cyclazocine and of l‐NANM, and decreased their agonist effects, but did not alter the effects of ketamine. Decreasing the training dose of morphine shifted the morphine gradient to the left and increased the agonist effects of cyclazocine, but did not alter the effects of l‐NANM and ketamine. The full generalization produced by cyclazocine when the training dose of morphine was lowered could be blocked completely by naltrexone and l‐NANM, but not by ketamine. These results suggest that cyclazocine and l‐NANM, but not ketamine, produced partial generalization because of their low efficacy at the receptor that underlies the DS effects of morphine. However, the results obtained with ketamine suggest that partial generalization may also be produced

ISSN:0272-4391    

DOI:10.1002/ddr.430160211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractWhen contrasting drugs (i.e., chlordiazepoxide versus pentylenetetrazol) are examined in drug‐drug, drug‐saline, or drug 1‐drug 2‐saline tasks, one can begin to assess whether such drugs represent orthogonal cues or reflect an underlying cue dimension. Both adaptation level theory and opponent‐process theory are applied to the analysis of drug discriminative performance. Three indices that can differentiate between orthogonal and opponent affective states utilizing drug‐drug discrimination tasks are discussed in relation to these two theories, and a model to characterize further the similarity between pharmacologically and environmentally induced anxiety

ISSN:0272-4391    

DOI:10.1002/ddr.430160212

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY