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Suarez M, Charntikov S, Huynh YW, Barrett ST, Bevins RA, Wakabayashi KT. "A robust and simple catheter connector assembly for long-term self-administration experiments". MethodsX 2024; 12:102675. [PMID: 38585181 PMCID: PMC10997883 DOI: 10.1016/j.mex.2024.102675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/22/2024] [Indexed: 04/09/2024] Open
Abstract
Intravenous self-administration in rats is used widely to study the reinforcing effects of drugs and serves as the gold standard for assessing their use and misuse potential. One challenge that researchers often encounter when scaling up experiments is balancing the cost, time investment to construct, and robustness of each implanted catheter. These catheters include multiple components such as surgical meshing and a variety of entry ports designed to facilitate the connection of the rat to a catheter port tethering system. Other considerations include maintaining the catheters free of blockage during the extent of the drug self-administration experiment. These large-scale studies provide ample opportunity for the catheter system to fail. The failure and replacement of commercially purchased catheters leads to ballooning expenses, and the failure of in-lab manufactured catheters requires the manufacture of reserves, also increasing costs, as these handmade products are inherently more variable. We have developed a catheter system that combines a commercially available implantable back-mounted entry connector system with inexpensive medical items such as surgical mesh, sutures, and an air-tight back flow prevention system to bolster the overall success of self-administration experiments.•Method to bolster commercially available jugular catheter components for long-lasting self-administration experiments.•Reduces the overall cost per unit of self-administration experiments.•Easily assembled by laboratory students and staff.
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Affiliation(s)
- Mauricio Suarez
- Neurocircuitry of Motivated Behavior Laboratory, Department of Psychology, University of Nebraska–Lincoln, 1220 T St. Lincoln, Nebraska 68588, United States
| | - Sergios Charntikov
- Department of Psychology, University of New Hampshire, 468 McConnell Hall, 15 Academic Way, Durham, NH 03824, United States
| | - Y. Wendy Huynh
- Behavioral Neuropharmacology Laboratory, Department of Psychology, University of Nebraska–Lincoln, 1220 T St. Lincoln, Nebraska 68588, United States
| | - Scott T. Barrett
- Behavioral Neuropharmacology Laboratory, Department of Psychology, University of Nebraska–Lincoln, 1220 T St. Lincoln, Nebraska 68588, United States
| | - Rick A. Bevins
- Behavioral Neuropharmacology Laboratory, Department of Psychology, University of Nebraska–Lincoln, 1220 T St. Lincoln, Nebraska 68588, United States
| | - Ken T. Wakabayashi
- Neurocircuitry of Motivated Behavior Laboratory, Department of Psychology, University of Nebraska–Lincoln, 1220 T St. Lincoln, Nebraska 68588, United States
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Thompson BM, Tracy ME, Huynh YW, Dwoskin LP, Barrett ST, Bevins RA. Varenicline serves as the training stimulus in the drug-discriminated goal-tracking task with rats: initial evaluation of potential neuropharmacological processes. Behav Pharmacol 2023; 34:12-19. [PMID: 36730812 PMCID: PMC9908820 DOI: 10.1097/fbp.0000000000000707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Varenicline (Chantix) is an FDA-approved smoking cessation aid that is pharmacologically similar to nicotine, the primary addictive component found within tobacco. In support of this similarity, previous drug discrimination research in rats has reported that the internal or interoceptive stimulus effects of nicotine and varenicline share stimulus elements. Those shared elements appear to be mediated, in part, by overlapping action at alpha4beta2-containing nicotinic acetylcholine receptors (nAChRs). The research supporting this conclusion, however, has only used nicotine, and not varenicline, as the training drug. Accordingly, we used the discriminated goal tracking (DGT) task in which 1 mg/kg varenicline signaled intermittent access to sucrose. On separate intermixed saline days, sucrose was not available. Rats acquired the discrimination as measured by a differential increase in dipper entries (goal tracking) evoked by varenicline. These rats then received a series of tests with several doses of varenicline, nicotine, nornicotine (a metabolite of nicotine and tobacco alkaloid), sazetidine-A (a partial alpha4beta2 agonist), PHA-543613 (an alpha7 agonist), and bupropion (a norepinephrine and dopamine reuptake inhibitor). Control of goal tracking by varenicline was dose-dependent. Nicotine and nornicotine evoked responding comparable to the varenicline training dose indicating full substitution. Sazetidine-A partially substituted for the varenicline stimulus, whereas bupropion and PHA-543613 evoked little to no varenicline-like responding. These findings indicate that varenicline can serve as the training stimulus in the DGT task. Further, stimulus control of varenicline in the DGT task is driven by its partial agonist activity at alpha4beta2-containing nAChRs. The use of this approach could lead to a better understanding of the pharmacological action of varenicline and help guide treatment geared towards tobacco cessation through a more targeted development of novel synthetically designed, subunit-specific pharmacological interventions.
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Affiliation(s)
| | | | - Y. Wendy Huynh
- Department of Psychology, University of Nebraska-Lincoln
| | - Linda P. Dwoskin
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky
| | | | - Rick A. Bevins
- Department of Psychology, University of Nebraska-Lincoln
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Barrett ST, Flynn AT, Huynh YW, Bevins RA. Appetitive Pavlovian conditioning of the stimulus effects of nicotine enhances later nicotine self-administration. J Exp Anal Behav 2022; 117:543-559. [PMID: 35192221 PMCID: PMC9090954 DOI: 10.1002/jeab.740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/21/2021] [Accepted: 01/10/2022] [Indexed: 11/10/2022]
Abstract
Nicotine produces robust stimulus effects that can be conditioned to exert stimulus control over behavior through associative learning. Additionally, nicotine has weak reinforcing effects that are inconsistent with its prevalence of use and the tenacity of nicotine dependence. The present study investigated whether conditioned associations to the nicotine drug stimulus may confer additional reinforcing strength to nicotine that thereby increase its use liability, and presents a new methodological approach to investigating the interaction between the stimulus effects and reinforcing effects of drugs. Male and female Sprague-Dawley rats were divided into groups receiving intravenous infusions of either 0.03 mg/kg nicotine or 0.9% saline that were either Paired (30 s delayed) or explicitly Unpaired (4 to 6 min delayed) with sucrose deliveries over 24 daily conditioning sessions. Thereafter, recessed nosepoke response devices were installed in the chambers and infusions of their assigned drug solutions were contingently available according to a progressive ratio schedule. Rats in the Paired Nicotine condition acquired the nosepoke response, expressed active nosepoke discrimination, and self-administered significantly more infusions than rats in any of the other groups. These results demonstrate that the interoceptive stimulus effects of nicotine can form Pavlovian associations with reinforcing events that alter its reinforcement efficacy.
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Affiliation(s)
| | | | - Y Wendy Huynh
- Department of Psychology, University of Nebraska, Lincoln
| | - Rick A Bevins
- Department of Psychology, University of Nebraska, Lincoln
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Thompson BM, Barrett ST, Huynh YW, Kwan DA, Murray JE, Bevins RA. The importance of acquisition learning on nicotine and varenicline drug substitution in a drug-discriminated goal-tracking task. Pharmacol Biochem Behav 2020; 199:173045. [PMID: 33058788 DOI: 10.1016/j.pbb.2020.173045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/17/2020] [Accepted: 10/05/2020] [Indexed: 11/25/2022]
Abstract
Nicotine and varenicline (Chantix®; the leading non-nicotine cessation pharmacotherapy) can come to control appetitive behaviors such as goal-tracking. We tested rats (N = 48) in a drug-discriminated goal-tracking (DGT) task where each rat received daily subcutaneous injections of either nicotine (0.4 mg/kg) or saline (0.9% [w/v]) interspersed across the acquisition phase (Phase 1). On saline days, sucrose was intermittently available. On nicotine days, sucrose was withheld. All rats acquired the discrimination with increased goal-tracking rates on saline days relative to nicotine days. Following acquisition, rats were separated into four groups to assess drug-substitution and discrimination reversal in Phase 2. The first group maintained the stimulus-reinforcer relation from acquisition (NIC-). The reversal group was now given access to sucrose on nicotine days (NIC+). The substitution group replaced nicotine with varenicline (1 mg/kg) while maintaining the acquisition stimulus-reinforcer relation (VAR-). The substitution and reversal group had nicotine replaced by varenicline and the stimulus-reinforcer relation reversed (VAR+). Rats in all groups learned or maintained their Phase 1 discriminations. For Phase 2, the reversal groups (+ conditions) acquired their discriminations within 10 sessions. The VAR- group displayed a pattern of disrupted discrimination at the outset of Phase 2 but was reestablished after continued training. In substitution testing, VAR groups received nicotine and NIC groups received varenicline. The NIC- and VAR- groups displayed full substitution of the test stimulus whereas the NIC+ and VAR+ groups displayed partial substitution of the test stimulus. Rats underwent nicotine extinction in Phase 3. Initial responding for each group mimicked Phase 2 training (i.e., higher responding by the reversal groups). All rats maintained similarly low levels of responding after six sessions. In conclusion, initial learning history with nicotine (i.e., + or -) influenced drug-stimulus substitution and the rate at which new learning (e.g., reversal) occurs with the varenicline and nicotine interoceptive stimuli.
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Affiliation(s)
- Brady M Thompson
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Scott T Barrett
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Y Wendy Huynh
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - David A Kwan
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Jennifer E Murray
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Rick A Bevins
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, USA.
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Huynh YW, Raimondi A, Finkner A, Kuck JD, Selleck C, Bevins RA. Menthol blunts the interoceptive discriminative stimulus effects of nicotine in female but not male rats. Psychopharmacology (Berl) 2020; 237:2395-2404. [PMID: 32448943 PMCID: PMC7354904 DOI: 10.1007/s00213-020-05542-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 04/27/2020] [Indexed: 01/29/2023]
Abstract
RATIONALE Menthol is a widely used tobacco constituent that has shown to enhance nicotine's reinforcing effects. OBJECTIVE To determine whether injected menthol also alters nicotine's stimulus effects, we used a drug discrimination task. METHODS A total of 57 adult Sprague-Dawley rats (28M, 29F) received 20 positive and 20 negative days (intermixed) of discrimination training. On positive days, rats received a group-specific menthol and nicotine injection (VEH + 0.1 NIC, 1 M + 0.1 NIC, 5 M + 0.1 NIC, VEH + 0.4 NIC, 1 M + 0.4 NIC, 5 M + 0.4 NIC; mg/kg) before eight 15-s cue light presentations (conditioned stimulus (CS)), each followed by 4-s sucrose access. On negative days, all rats were injected with vehicle and saline before eight non-reinforced CS presentations. Next, rats underwent generalization testing with 30 dose combinations of menthol and nicotine. The change in drug-mediated anticipatory goal tracking during the CS was calculated as a difference score (CS minus pre-CS responding). RESULTS All groups readily acquired drug discrimination. However, difference scores for the 5M + 0.1 NIC group were lower for females. Additionally, females had lower scores for 0.05, 0.1, and 0.4 mg/kg nicotine generalization tests. The lowest nicotine dose discriminable from saline was 0.05 mg/kg for females but 0.025 mg/kg for males. Co-administration with 5 or 10 mg/kg menthol weakened discrimination performance between 0.1 and 0.4 mg/kg and between 0.1 and 0.05 mg/kg nicotine for 0.1 mg/kg nicotine training groups. CONCLUSIONS Female rats that were trained with 0.1 mg/kg nicotine were more sensitive to menthol's modulatory effects on nicotine's stimulus effects. This highlights the importance of taking sex and training dose into account when evaluating the interoceptive stimulus effects of nicotine and menthol.
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Affiliation(s)
- Y Wendy Huynh
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Anthony Raimondi
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Andrew Finkner
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Jordan D Kuck
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Carly Selleck
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Rick A Bevins
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA.
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Huynh YW, Thompson BM, Larsen CE, Buch S, Guo ML, Bevins RA, Murray JE. Male HIV-1 transgenic rats show reduced cocaine-maintained lever-pressing compared to F344 wildtype rats despite similar baseline locomotion. J Exp Anal Behav 2020; 113:468-484. [PMID: 32077125 DOI: 10.1002/jeab.586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 01/29/2020] [Accepted: 02/02/2020] [Indexed: 12/12/2022]
Abstract
The HIV-1 transgenic (Tg) rat model is valuable for understanding HIV-associated neurocognitive disorders (HAND) and accompanying substance use and misuse. Tg and F344/NHsd wildtype (WT) rats were allowed to self-administer intrajugular cocaine. For the first 7 sessions, neither genotype self-administered cocaine (0.1 mg/kg/infusion) on a fixed ratio 1 schedule. We thus implemented a lever-cocaine "autoshaping" session followed by a series of manipulations changing dose and reinforcement schedule. Tg rats self-administered much less cocaine than WT rats throughout the study. Of 8 Tg rats, 5 modestly increased self-administration from sessions 36-50. Of those, only 3 showed a lever discrimination. Of 10 WT rats, 8 acquired robust self-administration by session 19; all WT rats self-administered cocaine by the end of the study. WT and Tg rats had similar baseline locomotor activity in the self-administration chamber suggesting that the low levels of cocaine intake in the Tg rats did not reflect a nonspecific motor impairment in this rat strain. Concomitant measurement of activity with self-administration revealed activity increases that followed increased cocaine intake. That relation held in Tg rats. Therefore, the present study provides evidence that HIV-1 Tg rats are less sensitive to the reinforcing effects of cocaine than their F344 WT counterparts.
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Affiliation(s)
- Y Wendy Huynh
- Department of Psychology, University of Nebraska-, Lincoln
| | | | | | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha
| | - Ming-Lei Guo
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha
| | - Rick A Bevins
- Department of Psychology, University of Nebraska-, Lincoln
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Huynh YW, Raimondi A, Schuster C, Finkner A, Selleck C, Bevins RA. Investigating the interoceptive stimulus effects of injected menthol in rats. Exp Clin Psychopharmacol 2020; 28:19-25. [PMID: 31070425 DOI: 10.1037/pha0000295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Menthol is a commonly used tobacco constituent that also modulates nicotine reinforcement and metabolism. Little is known about the stimulus effects of menthol that mediate the behavior associated with reinforcement-learning. Our present research explored the interoceptive stimulus effects of intraperitoneally administered menthol in a drug discrimination task. For Experiment 1, Sprague-Dawley rats (N = 20) received IP menthol (0.0183 or 5 mg/kg) or vehicle. For positive sessions, rats were given menthol before receiving 8 15-s light presentations, each followed by 4-s access to liquid sucrose. For intermixed negative sessions, rats were given vehicle before receiving 8 light presentations without sucrose delivery. After 32 sessions, rats previously receiving 0.0183 mg/kg menthol were switched to 15 mg/kg menthol. After 16 sessions, the injection-to-placement-interval was switched from 5 min to 15 min for 16 additional sessions. Lastly, a subset of rats (n = 10) received nicotine discrimination training for 40 sessions, with 0.4 mg/kg nicotine pretreatment on positive days and saline on negative days. In Experiment 2, naïve rats (N = 7) received nicotine discrimination training. Later sessions assessed nicotine discrimination performance in combination with 5 mg/kg menthol or vehicle. Menthol-vehicle discrimination was not evident regardless of dose or injection-to-placement interval in Experiment 1. However, rats that underwent nicotine training developed robust drug discrimination. In Experiment 2, co-exposure with menthol or vehicle did not modulate nicotine discrimination performance. These data suggest that menthol does not acquire control of responding in a drug discrimination task. Additional research is needed to further explore the interoceptive stimulus effects of menthol and nicotine combined. (PsycINFO Database Record (c) 2020 APA, all rights reserved).
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Randall PA, Fortino B, Huynh YW, Thompson BM, Larsen CE, Callen MP, Barrett ST, Murray JE, Bevins RA, Besheer J. Effects of nicotine conditioning history on alcohol and methamphetamine self-administration in rats. Pharmacol Biochem Behav 2019; 179:1-8. [PMID: 30664897 DOI: 10.1016/j.pbb.2019.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Smoking constitutes a significant public health risk. Alcohol and methamphetamine use disorders are also highly co-morbid with smoking, further increasing negative health outcomes. An important question in determining the underlying neurobiology of nicotine poly-drug use is understanding whether having a positive history with nicotine effects alters later drug-taking behavior. METHODS The current experiments sought to elucidate whether having an appetitive nicotine conditioning history would affect later alcohol or methamphetamine self-administration. Adult male and female Long-Evans rats were first trained on a discriminated goal-tracking task in which the interoceptive effects of nicotine predicted sucrose reinforcement. As a control, pseudo-conditioned groups were included that had equated nicotine and sucrose experience. Rats were then shifted to either alcohol self-administration or methamphetamine self-administration. RESULTS Nicotine conditioning history had no effect on acquisition or maintenance of alcohol self-administration in males or females. In contrast, an appetitive nicotine conditioning history decreased methamphetamine self-administration in female rats, but not males. CONCLUSIONS In female, but not male, rats, an appetitive conditioning history with nicotine decreases methamphetamine, but not alcohol, self-administration. This dissociation suggests that the effects may be due to a specific increase in the reinforcing value of methamphetamine. This may have implications for better understanding the progression of drug use from nicotine to methamphetamine.
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Affiliation(s)
- Patrick A Randall
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Brayden Fortino
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Y Wendy Huynh
- Department of Psychology, University of Nebraska at Lincoln, Lincoln, NE 68588, USA
| | - Brady M Thompson
- Department of Psychology, University of Nebraska at Lincoln, Lincoln, NE 68588, USA
| | - Christopher E Larsen
- Department of Psychology, University of Nebraska at Lincoln, Lincoln, NE 68588, USA
| | - Mackenzie P Callen
- Department of Psychology, University of Nebraska at Lincoln, Lincoln, NE 68588, USA
| | - Scott T Barrett
- Department of Psychology, University of Nebraska at Lincoln, Lincoln, NE 68588, USA
| | - Jennifer E Murray
- Department of Psychology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | - Rick A Bevins
- Department of Psychology, University of Nebraska at Lincoln, Lincoln, NE 68588, USA
| | - Joyce Besheer
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Curriculum in Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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Bevins RA, Barrett ST, Huynh YW, Thompson BM, Kwan DA, Murray JE. Experimental analysis of behavior and tobacco regulatory research on nicotine reduction. J Exp Anal Behav 2018; 110:1-10. [PMID: 29869329 DOI: 10.1002/jeab.439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 05/02/2018] [Indexed: 12/19/2022]
Abstract
With the signing of H.R. 1256, the Family Smoking Prevention and Tobacco Control Act, the United States Food and Drug Administration (FDA) gained regulatory authority over the tobacco industry. A notable clause in this Act permits the FDA to regulate nicotine yields. However, they cannot completely remove this addictive constituent from tobacco products. This restriction has prompted the FDA to seek research on the threshold dose of nicotine that does not support dependence. This idea of threshold dose has led to an interesting reframing of scientific questions. For example, some researchers studying nicotine from this regulatory perspective translated the notion of an addiction threshold to a construct thought to play a role in addiction but which can be more readily operationalized. Examples include reinforcement threshold, discrimination threshold, and reinforcer-enhancement threshold. In this Perspective Paper, we highlight the importance of behavioral pharmacology and, specifically, the experimental analysis of behavior to help establish a scientific basis for policy decisions regarding nicotine yields. Recent research, including exemplars provided herein, note vast individual differences in the effects of nicotine at a known dose. Unfortunately, the behavioral and biological factors that contribute to such individual variations remain to be understood. We believe that behavior analysts are uniquely well-positioned to contribute to this understanding.
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Affiliation(s)
| | | | | | | | - David A Kwan
- University of Nebraska - Lincoln, Lincoln, NE, USA
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