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| #189 Poster Session – BPH |
| Sunday, May 30, 2004 |
| 12:00 PM–1:30 PM |
| Exhibit Hall D (Hynes) |
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| 37. Acute and Chronic Effects of Nicotine on Observing Responses |
| Area: BPH; Domain: Applied Research |
| BETHANY R. RAIFF (University of Florida), Julie A. Marusich (University of Florida), Matthew L. Locey (University of Florida), Jesse Dallery (University of Florida) |
| Abstract: For smokers, nicotine is correlated with many sensory stimuli (e.g. smell of smoke, taste). In one day, a smoker might experience 300 such pairings between nicotine and the correlated sensory stimuli. Conditioned reinforcers are thought to gain their reinforcing efficacy through Pavlovian conditioning, so these stimuli might have reinforcing qualities apart from nicotine itself. Very little research has investigated acute and chronic effects of nicotine on responding for stimuli paired with primary reinforcers (Jentsch, 2003). Six rats were exposed to the observing response procedure, where one stimulus was paired with a variable-interval 45 food schedule and a different stimulus was paired with extinction. An observing response was required for schedule-correlated stimuli to appear for 10 sec. Rats were given 5 acute doses of nicotine or vehicle systemically. After 2 cycles of acute dosing they were given the same dose of nicotine every day for a minimum of 50 days. Observing response rates increased at intermediate doses of nicotine and decreased at high doses. Daily injections of nicotine also increased observing response rates. Aside from high dose suppressive effects, no systematic changes were noted on the other lever that produced food during VI components and had no consequence during EXT components. |
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| 38. Alternative Non-drug Reinforcement Decreases Drug-maintained Responding but Increases Resistance to Change |
| Area: BPH; Domain: Applied Research |
| K. ANNE BURKE (Utah State University), Corina Jimenez-Gomez (Utah State University), Timothy A. Shahan (Utah State University) |
| Abstract: Adding alternative sources of reinforcement decreases response rates by degrading the operant contingency and weakening the response-reinforcer relation. Resistance to change however is enhanced by added reinforcers, suggesting that the persistence of behavior is determined by the stimulus-reinforcer relation. Adding an alternative non-drug source of reinforcement reduces drug self-administration, but how this affects resistance to change has not been determined. The present experiment seeks to examine this phenomenon using drug self-administration with an alternative non-drug reinforcer. Four Long Evans rats self-administered a 10% Ethanol solution on RI 15s schedules during two components signaled by a blinking light and pulsing tone in one and a steady light and constant tone in the other. RT15s food deliveries were added to one component. In congruence with previous research, response rates in the ethanol + RT food component were lower than the rates in the ethanol only component. During extinction, responding for ethanol was more resistant to change in the component with added food, as predicted by the behavioral momentum theory. These results suggest that all reinforcers occurring in the context of a stimulus (in this case food and ethanol combined) add to the persistence of behavior maintained by that stimulus. |
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| 39. The Effects of Amphetamine on Variable and Repetitive Behavior |
| Area: BPH; Domain: Applied Research |
| ERICKA BAILEY (Utah State University), Ryan D. Ward (Utah State University), Amy Odum (Utah State University) |
| Abstract: Using a multiple schedule of reinforcement, the differential effects of amphetamine on variable and repetitive responding were studied. Four white Carneau pigeons with a history of responding on a variety of related operant procedures pecked keys during a multiple schedule. Two components, REPEAT and VARY, were used. In Experiment 1, the REPEAT component required that a four-response sequence matched one of the previous three sequences to produce food. In the VARY component, a four-response sequence had to differ from one of the previous three sequences to produce food. Acute administration of d-amphetamine produced a dose-dependent decrease in response rate. Amphetamine had little effect on the percentage of sequences meeting the contingency in VARY, but reduced somewhat the percentage of successful sequences in REPEAT. In Experiment 2, we used different VARY and REPEAT contingencies. In the VARY component, four-response sequences had to differ from the previous ten for food. In the REPEAT component, only the sequence Left-Left-Right-Right produced food. We are now examining the effects of a range of doses of amphetamine on behavior using this procedure. |
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| 40. Effects of D-amphetamine on Matching to Sample Duration |
| Area: BPH; Domain: Applied Research |
| KATHRYN A. SAULSGIVER (University of Florida), Erin A. McClure (Allegheny College), Clive D. L. Wynne (University of Florida) |
| Abstract: Present research used a Matching to Sample Duration procedure with four doses of d-amphetamines to examine the changes in the choose-long response. Pigeons were placed on a discrimination task where the houselight would illuminate for either 2 or 8 s and after no delay choosing the red or green stimulus light, respectively, produced reinforcement. Four intervening values were added as stimulus durations: 2.6, 3.48, 4.6, and 6.1 seconds. Comparisons of sigmoidal curves before, during and after drug administration were compared. A general flattening of the sigmoidal curve occurred under drug administration, indicating a disruption in the perception of all durations. |
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| 41. Food Deprivation and Caffeine Effects on Lever Pressing in the Rat |
| Area: BPH; Domain: Applied Research |
| JOSHUA KUEHLER (South Dakota State University), Doug Boe (South Dakota State University), Debra J. Spear (South Dakota State University) |
| Abstract: The effects of caffeine (3, 6, 20,50, 60, and 100 mg/kg) on lever pressing responses of rats was evaluated at 4 levels of food deprivation (100%, 90%, 85%, and 75%). All rats were presented with a multiple FR 10 FR 50 schedule of food delivery, where each component was in effect for 15 min, was accompanied by discriminative stimuli, and was presented twice in alternating ordering. Caffeine was administered by oral gavage 15 min prior to each test session. Responses under the FR 50 schedule were most sensitive to food deprivation level, while responses under the FR 10 were more resistant to the disruption of deprivation and only decreased when there was no or little food deprivation. Caffeine increased responding dose-dependently, with the effect being greatest at the greater deprivation level. |
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| 42. Effects of Ephedrine, Caffeine, and Their Combination on the Reinforcement Sensitivity of the Rats |
| Area: BPH; Domain: Applied Research |
| YULIYA E. ALEXEEVA (Illinois State University), Seshanand Chandrashekar (Illinois State University), Valeri Farmer-Dougan (Illinois State University) |
| Abstract: Ephedrine, a central nervous and cardiovascular systems stimulant, has been increasingly abused for weight loss, sexual stamina, and increased behavioral activation. Evidence suggests that caffeine can also increase an organism’s activation levels. Recent research has implied that an ephedrine and caffeine combination improves vigilance and attention at low doses (possibly increasing sensitivity to reinforcement) but at high levels may produce psychosis, which is detrimental to sensitivity to reinforcement. However, no recent investigations tested changes in sensitivity to reward using these drugs individually or in combination. The study examined changes in sensitivity to reinforcement across a series of concurrent variable interval schedules when rats were treated with ephedrine, caffeine, or a combination. Specifically, we predicted that low doses of caffeine or ephedrine alone would improve the animal’s sensitivity to reinforcement, while higher doses or combinations of the drugs should disrupt sensitivity. Data suggested that changes in animal’s sensitivity to reward were both dose and drug dependent. |
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| 43. Behavioral and Pharmacological Factors Modulating Caffeine Self-Administration |
| Area: BPH; Domain: Applied Research |
| SHANNA BABALONIS (University of North Carolina at Wilmington), Steven I. Dworkin (University of North Carolina at Wilmington) |
| Abstract: The self-administration paradigm provides a model which approximates the behavioral complexities of human drug abuse and is indispensable in identifying variables that potentiate or attenuate drug intake. Despite caffeine’s frequent self-administration by humans, its reinforcing effects in animals have received little to no attention. However, with the arrangement of specific parameters (food deprivation, drug dose, behavioral history and a rapid drug delivery system), the rodent self-administration procedure has the ability to assess caffeine’s reinforcing effects by consistently maintaining behavior at levels comparable to nicotine but distinctive from that of cocaine or heroin. Further evaluation of withdrawal and reinstatement using rodent models may elucidate factors influencing caffeine’s reinforcing effects and ubiquitous human self-administration. |
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| 44. Current Alcohol Usage as Establishing Operation for Inhalant Drug Choice |
| Area: BPH; Domain: Applied Research |
| DIANA J. WALKER (The University of Chicago), James P. Zacny (The University of Chicago) |
| Abstract: The concept of establishing operations was recently applied to genetic influences on behavior (Thompson, 2003). The present study applies this concept to drug-use history as an establishing operation for drug self-administration. Two experiments examined the reinforcing effects of inhaled anesthetics in light (LD) and moderate (MD) alcohol drinkers. Inhaled anesthetics are similar to abused inhalants but can be administered more safely and ethically. Experiment 1 consisted of four sessions, in which subjects sampled one nitrous oxide (N2O) dose (0-40%) and 100% O2 (placebo) for 10 min each. Later they chose nine times, once every 5 min, among N2O, placebo, or “neither.” Experiment 2 was identical, except the drug under study was sevoflurane (0-0.8%). In Experiment 1 six LD’s chose N2O 0-14 times (median=3), and seven MD’s chose N2O 3-26 times (median=13). In Experiment 2 eight LD’s chose sevoflurane 0-22 times (median=1), and seven MD’s chose sevoflurane 0-23 times (median=11). Median data suggest that N2O and sevoflurane may be more effective reinforcers for MD’s than for LD’s. The behavior-analytic conceptualization of drug-use patterns as establishing operations for the use of other drugs contrasts with more traditional psychopharmacology approaches, such as cross-tolerance or “gateway” theories, and could lead to effective treatment strategies. |
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| 45. Methadone-maintained Patients Prefer a Methadone/benzodiazepine Combination to Either Drug Alone |
| Area: BPH; Domain: Applied Research |
| R. STOCKTON MAXWELL (Temple University), Ralph Spiga (Temple University) |
| Abstract: Background: Methadone maintenance is a treatment for opioid dependent patients. These patients often abuse or are dependent on nicotine, cocaine, and benzodiazepines. This study examined the reinforcing effects of the combination of methadone and valium (i.e., benzodiazepines).
Methods: Methadone-maintained patients with a history of benzodiazepine abuse were recruited as participants. During a daily drug self-administration session, they could press either of two buttons appearing on the monitor or sit and do nothing. Preference for drug was assessed under a concurrent fixed-ratio fixed-ratio (conc FR128 FR128) schedule of drug self-administration. Completing the ratio requirement delivered 10 ml of drug solution (i.e., .03 mg/ml methadone or .01 mg/ml valium) to a cup. Participants were required to drink the solution before further responding counted toward the conc FR FR. Following training, five conditions were tested: 1) methadone vs. vehicle, 2) valium vs. vehicle, 3) methadone/valium combination vs. vehicle, 4) combination vs. methadone, and 5) combination vs. valium. Conditions were counterbalanced across participants and testing lasted for five days. Trials ended following 100 deliveries or one hour.
Results: In the drug vs. vehicle conditions (1-3), participants preferred drug over vehicle. In conditions combining methadone and valium, the combination was preferred over either drug alone. The current results confirm previous findings on the subjective reinforcing effects of a methadone/benzodiazepine combination with behavioral measures of preference.
This research was supported by NIDA Grant # DA-7943. |
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| 46. The Effects of Ad Lib Smoking and Nicotine Replacement on Social Behavior in a Modified Prisoner’s Dilemma Game |
| Area: BPH; Domain: Applied Research |
| EVAN ROBERTS (Temple University), Ralph Spiga (Temple University) |
| Abstract: Background: This study examined the effects of smoking abstinence, 0 mg, 2 mg, 4 mg nicotine gum, and ad lib smoking on the social interaction of dependent smokers. Methods: Participants were paired and each member of an interacting dyad had 5 mutually exclusive choices during a trial: cooperate, compete, punish, reward, or withdraw. These options appeared on the monitor screen at the beginning of a session. After selection of a letter (a choice), the choice of each participant was displayed on a monitor screen. Depending on the combination of choices, points were added to counters marked “Your Earnings” and “Other’s earnings” during the feedback phase of the trial. These counters were displayed on the monitor screen and were visible during the choice and feedback components of the trial. After the choices were viewed and the payoffs added to the numeric counters, a standardized set of messages was displayed on the monitor screen. Participants could communicate with each other by selecting a message. Following this communication component of the trial, the next trial was initiated by the reappearance of the numeric counters and the choices. This cycle was repeated 20 times during a session. Results: The mean number of cooperative and other prosocial choices were greater after both dyad members received 4 mg nicotine or smoked ad lib than after abstinence, 0 or 2 mg nicotine gum. The mean number of competitive, punitive, and withdrawal choices were greater following abstinence, 0, or 2 mg nicotine gum than after ad lib smoking or 4 mg nicotine gum. When one member of the pair smoked ad lib independently of the experimental condition of their partner, the mean number of cooperative choices of the member who was abstinent smoked, or received nicotine gum was comparable to the mean frequency observed after both partners had smoked ad lib.
This research was supported by NIDA Grants # DA-12725 and DA-06633 and by the Pennsylvania Department of Health Grant # RFA 02-07 057123192. |
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| 47. The Effects of Stimulant Medication on Motivation in Children with ADHD |
| Area: BPH; Domain: Applied Research |
| KIMBERLY J. BERRY (University of Arkansas, Little Rock), John J. Chelonis (University of Arkansas, Little Rock), Mark C. Edwards (University of Arkansas for Medical Sciences/ACH), Ronald L. Baldwin (University of Arkansas for Medical Sciences/ACH), Eldon G. Schulz (University of Arkansas for Medical Sciences/ACH), Merle G. Paule (National Center for Toxicological Research) |
| Abstract: This study compared motivation in children with a diagnosis of attention deficit hyperactivity disorder (ADHD) (n=21) to that of control children (n=19) on a Progressive Ratio (PR) task. Children with ADHD where participated in two sessions; one, on and off their prescribed dose of stimulant medication. The PR task required participants to respond for reinforcers (here, nickels) by increasing the work required to obtain each subsequent reinforcer. The task began when a lever extended from the behavioral testing panel, initially one press resulted in the delivery of a nickel reinforcer, and for each subsequent nickel the number of lever presses required increased by ten. The results indicated that children with ADHD regardless of medication status made significantly more nickels and made significantly more lever presses than children without ADHD. Such data suggest that children with ADHD are more motivated than control children to make simple responses to earn nickels. |
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| 48. Effects of Pentobarbital and Environmental Enrichment on the Behavior of Rats Exposed Prenatally to Methylmercury |
| Area: BPH; Domain: Applied Research |
| ALYSSA MILLARD (College of Charleston), Ashley Furr (College of Charleston), Lorie Sturtevant (College of Charleston), Erin B. Rasmussen (College of Charleston) |
| Abstract: Prenatal exposure to methylmercury has been shown to modify sensitivity to GABAergic compounds in adult rats. This study examined the role of environmental enrichment in modulating mercury-induced changes in sensitivity to pentobarbital in rats. Female rats were prenatally exposed to either 0 or 5 ppm methylmercury in their drinking water. Forty male offspring (20 from each exposure group) were selected and randomly assigned to either an enriched or impoverished environmental condition. The subjects were shaped to lever press under a DRH 9:4 schedule of reinforcement, in which 9 responses in 4 sec produces a reinforcer. Once stability was demonstrated, all rats were injected i.p. with 1-20 mg/kg pentobarbital. Results suggest a main effect of pentobarbital on reducing response rate, but little effect of methylmercury was exhibited. A main effect of environmental enrichment, however, was demonstrated. |
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| 49. Rates of Acquisition under a Percentile Schedule in Rats Exposed to Methylmercury on H high or Low DHA Diet |
| Area: BPH; Domain: Applied Research |
| JOHN C. HEATH (Auburn University), Wendy Donlin Washington (Auburn University), Phyllis Reile (Auburn University), M. Christopher Newland (Auburn University) |
| Abstract: Methylmercury is known to affect aversively the motor capabilities of rats, while docosahexaenoic acid (DHA), an omega-3 fatty acid, is thought to ameliorate the damage caused by methylmercury ingestion. Differential reinforcement of high rates (DRH) and fixed ratio schedules generate high rates of responding. A percentile schedule was developed that minimizes the effects of reinforcement rates and emphasizes motor ability. In the percentile schedule the last IRT must be shorter than the median of the last ten IRT’s to qualify for reinforcement thus subjects set their own rate of responding while maintaining a high rate of behavior. During acquisition of behavior IRT’s in the lower percentile range stabilizes faster than those in the higher percentile range. A study was conducted in which Long Evans rats exposed to 0.0ppm, 0.5ppm, and 5.0ppm of methylmercury on either a high or low DHA diet, in a 3x2 design, were subjected to a percentile schedule. Stabilization of acquisition rates at low and high percentile IRT’s were compared between the groups. |
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| 50. Performance Deficits in Brazilian Children Exposed to Environmental Lead |
| Area: BPH; Domain: Applied Research |
| LINCOLN DA SILVA GIMENES (University of Brazil), J. G. Tuga Angerami (Universidade Estadual Paulista - Bauru, Brazil), Patricia Regina L. Galvão (University of Brazil), Juliana Lima (University of Brazil), Maria Silvia F.A. Barros (Universidade Estadual Paulista - Bauru, Brazil) |
| Abstract: Following enviromental contamination by a car battery plant, over 200 children were detected as being contaminated with lead. About 100 children ranging from 7 to 12 years of age were evaluated in their performance in different neurobehavioral tests, presented through the Portuguese language version of the Behavioral Assessment and Research System - BARS. The children were ranked according to their concentration of lead in the blood, and the bottom third was compared to the top third regarding their perfomance in the tests. The results showed that the children with higher concentration of lead had some impairment in their performance, as compared to the children with lower concentration, at least in some of the test, e.g., Continuous Performance Test and Symbol-Digit Test. Social and educational implications are discussed |
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