Biomedical subjects

A Poling

Publications and source records attributed to A Poling.

At least 19 recordsLinked to original sources

PubMed2000

Effects of cocaine and morphine under mixed-ratio schedules of food delivery: support for a behavioral momentum analysis.

Previous studies have shown that ratio size influenced the development of tolerance under simple and multiple schedules, but not under progressive-ratio (PR) schedules. PR schedules share certain features with mixed-ratio (MR) schedules, and pilot data suggested that ratio size fails to modulate tolerance to cocaine or morphine under MR schedules. The present study examined more comprehensively the pre- and postchronic effects of cocaine and (in separate birds) morphine under MR schedules with fixed-ratio (FR) 5 and FR 95, FR 25 and FR 75, and FR 50 and FR 50 components. Acute doses of cocaine and morphine initially were given in an ascending series (beginning with 0.56 mg/kg) until responding was reduced to near-zero levels. Chronic (daily) dosing with a dose that reduced, but did not eliminate, responding then occurred until response rates stabilized. Finally, postchronic dose-response determinations were conducted. Both cocaine and morphine reduced response rates at all FR values. Tolerance was consistently observed to the effects of morphine, but not to those of cocaine. With both drugs the degree of tolerance observed did not vary as a function of FR value. These findings, like those obtained under PR schedules, indicate that ratio size does not always modulate drug tolerance. A behavioral momentum analysis of drug action appears to account for whether or not ratio size modulates tolerance, and such an analysis is provided.

Animals↗

PubMed2000

MDMA and learning: effects of acute and neurotoxic exposure in the rat.

In two experiments, the effects of MDMA on the acquisition of lever-press responding of rats were examined under procedures in which water delivery was delayed by 0, 10, or 20 s relative to the response that produced it. In the first study, experimentally naive, water-deprived rats received an intraperitoneal injection of MDMA (0, 1.0, 3.2, or 5.6 mg/kg) prior to one 8-h experimental session. Response acquisition was observed under all conditions at all drug doses. MDMA increased the total number of responses emitted and the total number of water deliveries earned in dose-dependent fashion, but only when reinforcement was immediate. Under conditions of delay, MDMA had no effect on either measure. Under all reinforcement conditions, higher doses of MDMA typically produced an initial reduction in lever pressing, and in that sense interfered with learning. In the second study, rats received an MDMA injection regimen previously shown to be neurotoxic. Control rats received saline solution according to the same injection schedule. Two weeks after completing the regimen, rats were water deprived and exposed to behavioral procedures as described for the first experiment. Although MDMA significantly reduced 5-HT and 5-HIAA levels in the striatum and prefrontal cortex, mean performance of rats exposed to MDMA did not differ from that of rats exposed to vehicle. Twenty-five percent of the rats exposed to MDMA and delayed reinforcement did fail to acquire responding, which suggests that further study of the effects of neurotoxic doses of MDMA on initial response acquisition is warranted.

Animals↗

PubMed1999

Acute and chronic effects of morphine under a progressive-ratio 25 schedule of food delivery.

The present study examined the effects of morphine in pigeons responding under a progressive-ratio 25 schedule of food delivery. Morphine initially reduced response rates and breaking points. With chronic exposure, tolerance developed to these effects. The magnitude of the observed tolerance was not obviously different from that previously reported under a PR 5 schedule of food delivery. In addition, when drug effects were compared under the fixed-ratio 25 and fixed-ratio 100 components comprised by the progressive-ratio schedule, comparable tolerance was observed. Although prior studies using other procedures have shown that ratio size modulates the development of tolerance to morphine and other drugs, the present data suggest that this relation is constrained, and is not easily observed under progressive-ratio schedules.

Analgesics, Opioid↗

PubMed1999

Direct service staff and their perceptions of psychotropic medication in non-institutional settings for people with intellectual disability.

Previous studies have surveyed a variety of service providers in school and institutional settings, and reported a pervasive lack of education and training with regard to the use of psychotropic medication in people with intellectual disability. Because an increasing number of people with intellectual disability are living in the community and since many of these people receive psychotropic medications, the present study extended research in this area by surveying direct service staff to determine their perceptions, knowledge and opinions with regard to the use of psychotropic medication in non-institutional settings for individuals with developmental disabilities. Consistent with the findings of previous studies, a majority of the 334 respondents in the present study reported that they had not received adequate training in the area of drug treatment The knowledge and skills deficits of direct service staff appear to represent a significant barrier to the appropriate monitoring and management of pharmacotherapy for individuals with intellectual disability. Therefore, a systematic training programme to educate direct service staff about psychotropic medication needs to be designed, implemented and disseminated on a broad scale.

Attitude of Health Personnel↗

PubMed1998

Establishing morphine and U-50,488H as discriminative stimuli in a three-choice assay with pigeons.

Pigeons were trained in a 3-choice assay to discriminate among injections of 5.6 mg/kg U-50,488H, 5.6 mg/kg morphine, and vehicle solution. In dose-response tests, subjects rarely responded on the U-50,488H-appropriate key when morphine was administered or on the morphine-appropriate key when they received U-50,488H. A high dose of naltrexone (1.0 mg/kg) completely blocked the morphine cue but failed to block completely the U-50,488H cue. In generalization tests, d-amphetamine primarily engendered saline-appropriate responding. Ethylketazocine produced mixed results, in that moderate doses produced responding on both the morphine- and U-50,488H-appropriate keys, but 3.2 mg/kg engendered primarily morphine-appropriate responding. These results demonstrate the feasibility, but not necessarily the value, of 3-choice discrimination procedures involving mu and kappa agonists and vehicle.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

PubMed1998

Response acquisition with delayed reinforcement: a comparison of two-lever procedures.

Groups of 8 experimentally naive rats were exposed during 8-hr sessions to resetting delay procedures in which responses on one lever (the reinforcement lever) produced water after a delay of 8, 16, 32, or 64 s. For rats in one condition, responses on a second (no-consequences) lever had no programmed consequences. For rats in another condition, responses on a second (cancellation) lever during a delay initiated by a response on the reinforcement lever prevented delivery of the scheduled reinforcer; responses on the cancellation lever at other times had no programmed consequences. Under both conditions and at all delays, most subjects emitted more responses on the reinforcement lever than did control rats that never received water emitted on either lever. At 8-s delays, both conditions engendered substantially more responding on the reinforcement lever than on the other lever, and performance closely resembled that of immediate-reinforcement controls. At delays of 16 and 32 s, however, there was clear differential responding on the two levers under the cancellation condition but not under the other condition. When the delay was 64 s, differential responding on the two levers did not occur consistently under either condition. These findings provide strong evidence that the behavior of rats is sensitive to consequences delayed by 8, 16, and 32 s, but only equivocal evidence of such sensitivity to consequences delayed 64 s. They also indicate that acquisition depends, in part, on the measure of performance used to index it.

Animals↗

PubMed1997

Effects of chlorpromazine on rats' acquisition of lever-press responding with immediate and delayed reinforcement.

The effects of chlorpromazine (0, 2, 6, and 10 mg/kg) on the acquisition of lever-press responding by rats were examined under conditions where reinforcement (water delivery) was immediate or delayed. Under the immediate reinforcement condition, water-deprived rats were exposed during 8-h sessions to a fixed-ratio 1 (FR 1) schedule of water delivery without prior autoshaping or hand shaping. Under the delayed reinforcement condition, similar rats were exposed to a tandem FR 1 fixed-time 8-s schedule of water delivery. A different squad of eight rats was exposed to each delay condition and drug dose. For all subjects, responses on one lever produced water and responses on a second lever had no programmed consequences. Regardless of whether reinforcement was immediate or delayed, chlorpromazine reduced in dose-dependent fashion the mean number of operative-lever responses emitted, which suggests that the drug interfered with learning. At all chlorpromazine doses except 10 mg/kg, substantially more operative-lever than inoperative-lever responding occurred, indicating that the operant response was acquired. Chlorpromazine at 2 and 6 mg/kg disrupted the acquisition of stimulus control by the operative lever when reinforcement was delayed, but not when it was immediate. At 10 mg/kg, most subjects did not acquire lever-pressing regardless of whether they were exposed to the immediate or delayed reinforcement procedure. Procedures similar to those used in the present study appear to provide a reasonable assay for examining how drugs affect the initial behavioral effects of immediate and delayed reinforcement, and may merit further investigation.

Animals↗

PubMed1997

Drug abuse in persons with mental retardation: a review.

The literature on drug abuse by people with mental retardation, a real, but largely ignored problem, was reviewed. Topics addressed were (a) the prevalence of drug use, (b) the drug-related problems characteristically encountered by this population, (c) the special vulnerabilities of people with mental retardation, (d) the treatment programs used with (and appropriate for) people with mental retardation, and (e) the status of drug abuse prevention and drug education for this population. Controlled research dealing with the genesis, treatment, and prevention of drug abuse among people with mental retardation is essentially nonexistent, but badly needed.

Alcoholics Anonymous↗

PubMed1997

Using self-management procedures to improve the productivity of adults with developmental disabilities in a competitive employment setting.

This study describes the use of self-management procedures, similar to those proposed by Lagomarcino, Hughes, and Rusch (1989), to improve the productivity of 2 women with mild mental retardation who worked in restaurants. Substantial improvements were observed as a function of treatment, and the procedures were deemed acceptable by the participants, their coworkers, and their supervisors.

Adult↗

PubMed1996

Failure to induce defecation in rats exposed to fixed-time schedules of liquid food delivery.

Previous studies have found that defecation increases in rats exposed to fixed-time schedules of dry food delivery. The purpose of the present study was to examine whether increases in defecation could be induced in rats exposed to fixed-time schedules of liquid food delivery. Eight rats were exposed to fixed-time 30-, 60-, and 120-s schedules of liquid food delivery. None of the subjects excreted significantly more fecal boli under the fixed-time schedules than during massed-food control sessions in which an equivalent amount of food was presented at the beginning of the sessions. Thus, the present findings identify a previously unknown constraint on schedule-induced defecation in rats.

Animals↗

PubMed1996

Acute and chronic effects of morphine in pigeons responding under a progressive-ratio schedule of food delivery.

Although progressive-ratio schedules have often been used by behavioral pharmacologists to index the relative reinforcing effects of drugs of abuse, they have been ignored in the study of tolerance to opioids. The present study examined tolerance to morphine in pigeons responding under a progressive-ratio 5 schedule of food delivery. Acute administrations of morphine produced general dose-dependent reductions in response rates and breaking points. Dose-response curves for both measures shifted rightward substantially (roughly fivefold) following chronic (daily) exposure to morphine, indicating that tolerance developed to the drug's effects.

Animals↗

PubMed1996

Concurrent-schedule performance in dairy cows: persistent undermatching.

Performance of dairy cows responding under concurrent variable-interval variable-interval schedules of food delivery was examined, with results analyzed in terms of the generalized matching equation. In Experiment 1, bias measures indicated that crushed barley was preferred over meatmeal when these foods were available under the alternative schedules. For whole-session data, substantial undermatching of response and time-allocation ratios to obtained reinforcement ratios was evident. Postreinforcement pause time ratios approximately matched obtained reinforcement rates. Subtracting these times from total time-allocation values yielded net time-allocation ratios that undermatched obtained reinforcement ratios to a greater degree than did whole-session time-allocation ratios. In Experiment 2, substantial undermatching was evident when the same foods (hay for 2 cows, crushed barley for 2 others) were available under the alternative schedules. Food-related activities and other defined behavior not related to food were quantified by direct observation, and were found to occupy a substantial proportion (roughly 40% to 80%) of experimental sessions. Subtracting the time spent in these activities from the time allocated to each component schedule did not reduce the degree of undermatching obtained. Across all conditions in both experiments, slopes of regression lines relating behavioral outputs to environmental inputs characteristically were below 0.6, which agrees with prior findings and suggests that, contrary to suggestions in the literature, undermatching in dairy cows is not the result of using different foods under alternative schedules or differential pausing under those schedules.

Animals↗

PubMed1996

Effects of D-amphetamine on response acquisition with immediate and delayed reinforcement.

The present study examined in 8-hour sessions the effects of d-amphetamine (1.0, 5.6, and 10 mg/kg) on the acquisition of lever-press responding in rats that were exposed to procedures in which water delivery was delayed by 0, 8, or 16 seconds relative to the response that produced it. Both nonresetting- and resetting-delay conditions were studied. Although neither shaping nor autoshaping occurred, substantial levels of operative-lever responding developed under all conditions in which responses produced water. The lowest dose (1.0 mg/kg) of d-amphetamine either had no effect on or increased operative-lever pressing, whereas higher doses typically produced an initial reduction in lever pressing. Nonetheless, overall rates of operative-lever pressing at these doses were as high as, or higher than, those observed with vehicle. Thus, response acquisition was observed under all reinforcement procedures at all drug doses. In the absence of the drug, most responding occurred on the operative lever when reinforcement was immediate. Such differential responding also developed under both nonresetting- and resetting-delay procedures when the delay was 8 seconds, but not when it was 16 seconds. d-Amphetamine did not affect the development of differential responding under any procedure. Thus, consistent with d-amphetamine's effects under repeated acquisition procedures, the drug had no detrimental effect on learning until doses that produced general behavioral disruption were administered.

Amphetamines↗

PubMed1995

Schedule-induced defecation: a demonstration in pigeons exposed to fixed-time schedules of food delivery.

Previous studies have found that defecation increases in rats exposed to intermittent schedules of food delivery. In the present study, food-deprived pigeons were exposed to fixed-time 30-, 60-, 120-, and 240-s schedules of food delivery. For the subjects as a group, significantly more defecation (indexed by fecal weight) occurred under the fixed-time 60-s schedule than during massed-food control sessions in which an equivalent amount of food was presented. Thus, the present findings suggest that schedule-induced defecation occurs in pigeons.

Animals↗

PubMed1995

Effects of cocaine in pigeons responding under a progressive-ratio schedule of food delivery.

Although the progressive-ratio schedule has been used frequently to quantify the reinforcing effectiveness of self-administered drugs, it has seldom been used to examine the effects of drugs on food-maintained behavior and has never been used to evaluate the effects of cocaine on such behavior. In the present study, the effects of acute administrations of cocaine were evaluated in pigeons responding under a progressive-ratio 5 schedule of food delivery that continued for 1 h or until responding ceased for 5 consecutive min, whichever occurred first. The largest ratio completed each session (breaking point) was the primary dependent variable. In general, acute administrations of cocaine at 0.56 to 3.2 mg/kg increased breaking points, whereas doses above 5.6 mg/kg decreased breaking points. Although cocaine reduces food intake and subjective hunger for food, the present data indicate that the drug reduces the reinforcing effectiveness of food only at high doses.

Animals↗

PubMed1995

The effects of differing response-force requirements on fixed-ratio responding of rats.

Rats were exposed to two-component multiple schedules of food delivery. In the first experiment, 15 responses were required to produce food in both components. A downward force of 0.25 N (25 g) was always required to operate the response lever in one component. In the other, the required force was 0.25, 0.50, 1.00, or 2.00 N (25, 50, 100, or 200 g). In the second experiment, 0.25 N of force operated the lever in one component, but in the other, the force requirement for five consecutive responses at the beginning, middle, or end of each ratio was increased from 0.25 to 2.00 N. In the third experiment, the number of responses required to produce food was reduced from 15 to 5, and then to 1. Again, the effects of altering response force from 0.25 to 2.00 N were examined. In general, as response force increased in all experiments, mean response rates decreased and mean interresponse times increased.

Animals↗

PubMed1995

Delayed matching-to-sample performance of hens: Effects of sample duration and response requirements during the sample.

Six domestic hens were trained under a delayed matching-to-sample procedure with red and green keylights as sample and comparison stimuli and a 1.5-s delay interval. The hens were trained to stop pecking the sample stimuli when a tone sounded. Duration of the sample stimuli (2 to 10 s) and the number of pecks required on the key on which these stimuli were presented (0 to 10) were altered across conditions. Both the response requirement on the sample key and the duration of sample presentations affected accuracy. These findings are in agreement with those of earlier studies using other species and somewhat different procedures.

Journal Article↗

PubMed1995

Evaluating psychotropic drugs in people with mental retardation: where are the social validity data?

In general, social validity data reflect the social significance of target behaviors, the appropriateness of procedures, and the perceived importance of results. These data are important insofar as they predict whether a given intervention will be used and, if used, whether consumers are likely to be satisfied with it. Despite the importance of social validity data, a survey of articles published from 1987 through 1993 in five major journals revealed that none of the 68 articles concerned with the psychopharmacology of mental retardation reported social validity data.

Humans↗