1
|
Algallal HE, Jacquemet V, Samaha AN. Intermittent nicotine access is as effective as continuous access in promoting nicotine seeking and taking in rats. Psychopharmacology (Berl) 2024:10.1007/s00213-024-06546-4. [PMID: 38326505 DOI: 10.1007/s00213-024-06546-4] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 01/20/2024] [Indexed: 02/09/2024]
Abstract
RATIONALE Nicotine is a principal psychoactive agent in tobacco, contributing to tobacco's addictive potential. Preclinical studies on the effects of voluntary nicotine intake typically use self-administration procedures that provide continuous nicotine access during each self-administration session. However, many smokers consume cigarettes intermittently rather than continuously throughout each day. For drugs including cocaine and opioids, research in laboratory rats shows that intermittent intake can be more effective than continuous intake in producing patterns of drug use relevant to addiction. OBJECTIVE We determined how intermittent versus continuous nicotine self-administration influences nicotine seeking and taking behaviours. METHODS Female and male rats had continuous (i.e., Long Access; LgA, 6 h/day) or intermittent (IntA; 12 min ON, 60 min OFF, for 6 h/day) access to intravenous nicotine (15 µg/kg/infusion), for 12 daily sessions. We then assessed intake, responding for nicotine under a progressive ratio schedule of drug reinforcement and cue- and nicotine-induced reinstatement of drug seeking. We also estimated nicotine pharmacokinetic parameters during LgA and IntA self-administration. RESULTS Overall, LgA rats took twice more nicotine than did IntA rats, yielding more sustained increases in estimated brain concentrations of the drug. However, the two groups showed similar motivation to seek and take nicotine, as measured using reinstatement and progressive ratio procedures, respectively. CONCLUSIONS Intermittent nicotine use is just as effective as continuous use in producing addiction-relevant behaviours, despite significantly less nicotine exposure. This has implications for modeling nicotine self-administration patterns in human smokers and resulting effects on brain and behaviour.
Collapse
Affiliation(s)
- Hajer E Algallal
- Biomedical Sciences, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Vincent Jacquemet
- Institute of Biomedical Engineering, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC, H3C 3J7, Canada
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC, H3C 3J7, Canada.
- Neural Signaling and Circuitry Research Group (SNC), Faculty of Medicine, Université de Montréal, Montreal, QC, Canada.
- Center for Interdisciplinary Research On the Brain and Learning (CIRCA), Université de Montréal, Montreal, QC, Canada.
| |
Collapse
|
2
|
AlTfaili H, Ginsburg BC, Lamb RJ. Ethanol-paired conditioned stimulus effects on concurrent reinforced responding for ethanol and food. Alcohol 2023; 111:17-23. [PMID: 36898642 PMCID: PMC10512455 DOI: 10.1016/j.alcohol.2023.02.002] [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: 11/18/2022] [Revised: 02/09/2023] [Accepted: 02/27/2023] [Indexed: 03/11/2023]
Abstract
The influence of Pavlovian Conditioned Stimuli (CS) on ethanol self-administration and choice between ethanol and an alternative are potentially important. Ethanol-paired CS might increase ethanol self-administration, especially when it has been reduced during recovery, though the selectivity of these increases has been questioned. To date, one study examined the effects of an ethanol-paired CS on ethanol choice and found that the CS increased ethanol-responding more than food-responding when both were in extinction. However, it remains unclear whether ethanol-paired CS increase ethanol-choice that is not in extinction. Here, we examine the effects of an ethanol-paired CS on ethanol-choice when both food- and ethanol-responding are reinforced. Sixteen adult male Lewis rats were trained on a concurrent schedule to respond for ethanol on one lever and for food on the other lever. Ethanol was available under an FR 5 schedule, and food was available under an FR schedule that was adjusted for each rat to earn an equal number of food and ethanol deliveries. Then, 2-min light presentations were paired with an RT 25-sec schedule of ethanol delivery for 10 sessions in the absence of both levers. After this, subjects were placed back on the concurrent schedule for one session, then five sessions with the CS being present or absent on each trial of the concurrent schedule occurred. Rats learned to respond on one lever for ethanol and on the other for food and earned similar numbers of ethanol and food deliveries. During Pavlovian Conditioning, the number of head entries into the head-entry detector was higher in the presence of the CS than in its absence. In the test sessions, rats made more ethanol responses in the presence of the CS than in its absence. However, this effect was small and did not increase the amount of ethanol earned. Thus, ethanol-paired CS could increase ethanol-responding under a choice procedure but did not increase ethanol consumption meaningfully under the studied conditions.
Collapse
Affiliation(s)
- Hanana AlTfaili
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Brett C Ginsburg
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
| | - R J Lamb
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| |
Collapse
|
3
|
Mueller PM, Peng DN, Zentall TR. "Distractor" effects in delay discounting of probability by pigeons. Anim Cogn 2023; 26:1073-1081. [PMID: 36853524 DOI: 10.1007/s10071-023-01759-0] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/14/2022] [Accepted: 02/16/2023] [Indexed: 03/01/2023]
Abstract
Impulsive behavior can be measured by performance on a successive delay-discounting task, in which a response to a stimulus provides a small reinforcer sooner (SS), but in the absence of a response, a larger reinforcer later (LL). Previous research suggests that the presence of a concurrent "distractor" stimulus, to which responding has no programed consequence, can result in increased LL reinforcers. In the present experiments, we used differences in the probability of reinforcement between SS and LL (rather than magnitude of reinforcement) and tested the hypothesis that the concurrent stimulus may become a Pavlovian conditioned stimulus. For the Red-Only group, a response to the SS stimulus resulted in a reinforcer with a low probability (SS), whereas the absence of a response resulted in a reinforcer with a high probability (LL). For the Red-Green group, (analogous to the more typical simultaneous choice between an SS and LL stimulus) the absence of a response to the SS stimulus replaced the SS stimulus with the LL stimulus and a response to the LL stimulus resulted in the reinforcer. Thus, for the Red-Green group, the concurrent stimulus should have been less effective because responding to the concurrent stimulus was not immediately followed by the reinforcer. In Experiment 1, the concurrent stimulus was a yellow key-light; in Experiment 2, it was a houselight. In both experiments, the concurrent stimulus was effective in increasing the number of LL reinforcers and the effect was larger for the Red-Only group than for the Red-Green group.
Collapse
Affiliation(s)
- Peyton M Mueller
- Department of Psychology, University of Kentucky, 40506-0044, Lexington, KY, USA
| | - Daniel N Peng
- Department of Psychology, University of Kentucky, 40506-0044, Lexington, KY, USA
| | - Thomas R Zentall
- Department of Psychology, University of Kentucky, 40506-0044, Lexington, KY, USA.
| |
Collapse
|
4
|
Wolter M, Lapointe T, Melanson B, Baidoo N, Francis T, Winters BD, Leri F. Memory enhancing effects of nicotine, cocaine, and their conditioned stimuli; effects of beta-adrenergic and dopamine D2 receptor antagonists. Psychopharmacology (Berl) 2021; 238:2617-2628. [PMID: 34175982 DOI: 10.1007/s00213-021-05884-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 05/27/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND There is evidence that post-training exposure to nicotine, cocaine, and their conditioned stimuli (CS), enhance memory consolidation in rats. The present study assessed the effects of blocking noradrenergic and dopaminergic receptors on nicotine and cocaine unconditioned and conditioned memory modulation. METHODS Males Sprague-Dawley rats tested on the spontaneous object recognition task received post-sample exposure to 0.4 mg/kg nicotine, 20 mg/kg cocaine, or their CSs, in combination with 5-10 mg/kg propranolol (PRO; beta-adrenergic antagonist) or 0.2-0.6 mg/kg pimozide (PIM; dopamine D2 receptor antagonist). The CSs were established by confining rats in a chamber (the CS +) after injections of 0.4 mg/kg nicotine, or 20 mg/kg cocaine, for 2 h and in another chamber (the CS -) after injections of vehicle, repeated over 10 days (5 drug/CS + and 5 vehicle/CS - pairings in total). Object memory was tested 72 h post sample in drug-free animals. RESULTS Co-administration of PRO or PIM blocked the memory-enhancing effects of post-training injections of nicotine, cocaine, and, importantly, exposure to their CSs. CONCLUSIONS These data suggest that nicotine, cocaine as well as their conditioned stimuli share actions on overlapping noradrenergic and dopaminergic systems to modulate memory consolidation.
Collapse
Affiliation(s)
- Michael Wolter
- Department of Psychology, Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - Thomas Lapointe
- Department of Psychology, Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - Brett Melanson
- Department of Psychology, Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - Nana Baidoo
- Department of Psychology, Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - Travis Francis
- Department of Psychology, Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - Boyer D Winters
- Department of Psychology, Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - Francesco Leri
- Department of Psychology, Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada.
| |
Collapse
|
5
|
Wolter M, Huff AE, Baidoo N, Jardine KH, Pulles Z, Winters BD, Leri F. Modulation of object memory consolidation by heroin and heroin-conditioned stimuli: Role of opioid and noradrenergic systems. Eur Neuropsychopharmacol 2020; 33:146-157. [PMID: 32067860 DOI: 10.1016/j.euroneuro.2020.01.010] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/21/2019] [Accepted: 01/22/2020] [Indexed: 11/18/2022]
Abstract
There is recent evidence that cocaine, nicotine, and their conditioned stimuli have the ability to enhance memory consolidation. The present study compared the effects of post-training heroin and of a heroin contextual conditioned stimulus (CS+) on consolidation of object recognition memory and investigated the roles of opioid and beta-adrenergic receptors in heroin/CS+ memory modulation by co-administering the respective antagonists, naltrexone (NTX) and propranolol (PRO). Three experiments were performed in male Sprague-Dawley rats demonstrating that immediate, but not delayed, post-sample exposure to heroin (0.3, 1 mg/kg), or exposure (30 min) to a contextual CS+ paired with 1 mg/kg heroin (5 pairings, each 120 min), equally enhanced object memory. Importantly, while the memory enhancing effects of 1 mg/kg heroin and of the contextual CS+ were not altered by post-training co-administration of 3 mg/kg naltrexone, they were blocked by post-training co-administration of 10 mg/kg propranolol. Taken together, these data suggest that a context paired with heroin shares the memory enhancing effect of heroin itself and that these unconditioned and conditioned drug stimuli may modulate memory through the activation of beta-noradrenergic receptors.
Collapse
Affiliation(s)
- Michael Wolter
- Department of Psychology & Collaborative Neuroscience Program, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, ON, Canada
| | - Andrew E Huff
- Department of Psychology & Collaborative Neuroscience Program, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, ON, Canada
| | - Nana Baidoo
- Department of Psychology & Collaborative Neuroscience Program, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, ON, Canada
| | - Kristen H Jardine
- Department of Psychology & Collaborative Neuroscience Program, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, ON, Canada
| | - Zoey Pulles
- Department of Psychology & Collaborative Neuroscience Program, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, ON, Canada
| | - Boyer D Winters
- Department of Psychology & Collaborative Neuroscience Program, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, ON, Canada
| | - Francesco Leri
- Department of Psychology & Collaborative Neuroscience Program, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, ON, Canada.
| |
Collapse
|
6
|
Harrison E, Biswas L, Avusula R, Zhang M, Gong Y, Liu X. Effects of menthol and its interaction with nicotine-conditioned cue on nicotine-seeking behavior in rats. Psychopharmacology (Berl) 2017; 234:3443-53. [PMID: 28918457 DOI: 10.1007/s00213-017-4736-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 08/24/2017] [Indexed: 10/18/2022]
Abstract
RATIONALE Increasing clinical evidence suggests that menthol, a significant flavoring additive in tobacco products, may contribute to smoking and nicotine dependence. Relapse to smoking behavior presents a formidable challenge for the treatment of tobacco addiction. An unresolved issue is whether the mentholation of tobacco products precipitates relapse to tobacco use in abstinent smokers. OBJECTIVES The present study examined the effects of menthol on the perseverance and relapse of nicotine-seeking behavior in rats. METHODS Male Sprague-Dawley rats were trained to press a lever for intravenous nicotine self-administration (0.03 mg/kg/infusion) under a fixed-ratio five schedule of reinforcement. Each nicotine infusion was signaled by the presentation of a sensory stimulus that was established as a discrete nicotine-conditioned cue. Five minutes prior to the sessions, the rats received an intraperitoneal injection of menthol (0.1 mg/kg) or vehicle. In the subsequent extinction test sessions, nicotine was unavailable with or without menthol and/or the nicotine-conditioned cue. The reinstatement tests were performed the following day after the extinction criterion was met. Menthol was also tested on food-seeking responses. In a subset of nicotine-trained rats, a transient receptor potential melastatin 8 (TRPM8) antagonist RQ-00203078 was given prior to menthol administration. RESULTS Continued administration of menthol sustained responses on the previously active and nicotine-reinforced lever in the extinction tests. The readministration of menthol after extinction reinstated active lever responses. In both the extinction and the reinstatement tests, a combination of pre-session menthol administration and cue representation during the session produced a more robust behavioral effect than either menthol or the cue alone. No such effects of menthol was observed in food trained rats. RQ-00203078 did not change menthol effect on nicotine seeking. CONCLUSION These data demonstrated that menthol specifically sustained and reinstated nicotine-seeking behavior, and this effect was independent of TRPM8 activity. These findings suggest that menthol in most tobacco products, even not menthol labeled, may contribute to the perseverance of and relapse to tobacco-seeking behavior.
Collapse
|
7
|
Venniro M, Mutti A, Chiamulera C. Pharmacological and non-pharmacological factors that regulate the acquisition of ketamine self-administration in rats. Psychopharmacology (Berl) 2015; 232:4505-14. [PMID: 26387516 DOI: 10.1007/s00213-015-4077-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 09/07/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Recreational ketamine use may be modulated by factors such as ketamine infusion patterns, associated conditioned stimuli and spatial-temporal contexts. Our aim was to study the pharmacological and non-pharmacological factors that regulate the acquisition of ketamine use. METHODS In experiment 1, four groups of male rats were trained to self-administer ketamine during nine 1-h daily sessions, under four reinforcement schedules: i) pre-session ketamine priming (Priming-[KET]), ii) conditioned stimulus (CS) paired to the ketamine infusions ([KET + CS]), iii) neither priming nor CS ([KET]), iv) combination of both (Priming-[KET + CS]). In experiment 2, two groups of male rats were trained to self-administer ketamine during nine 1-h daily or weekly sessions, under the Priming-[KET + CS] schedule. Lever pressing was then extinguished by saline substitution for ketamine infusion. Afterwards, ketamine was made available again upon responding under the same schedule. RESULTS The Priming-[KET + CS] schedule of reinforcement showed a significant increase in the number of ketamine reinforcements and a significant discrimination between active vs. inactive levers. The same schedule allowed the establishment of ketamine self-administration on a weekly basis. During the extinction phase, rate of responding significantly dropped in both weekly and daily groups although it was twofold longer in the former, which showed a lack of reacquisition. CONCLUSIONS Both pre-session ketamine priming and a conditioned stimulus paired to the ketamine infusions are required for the acquisition of ketamine self-administration. The longer extinction and the lack of reacquisition in the weekly group could be due to changes in temporal context that might affect the conditioning process.
Collapse
|
8
|
Morice E, Farley S, Poirier R, Dallerac G, Chagneau C, Pannetier S, Hanauer A, Davis S, Vaillend C, Laroche S. Defective synaptic transmission and structure in the dentate gyrus and selective fear memory impairment in the Rsk2 mutant mouse model of Coffin-Lowry syndrome. Neurobiol Dis 2013; 58:156-68. [PMID: 23742761 DOI: 10.1016/j.nbd.2013.05.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 04/18/2013] [Accepted: 05/27/2013] [Indexed: 12/20/2022] Open
Abstract
The Coffin-Lowry syndrome (CLS) is a syndromic form of intellectual disability caused by loss-of-function of the RSK2 serine/threonine kinase encoded by the rsk2 gene. Rsk2 knockout mice, a murine model of CLS, exhibit spatial learning and memory impairments, yet the underlying neural mechanisms are unknown. In the current study, we examined the performance of Rsk2 knockout mice in cued, trace and contextual fear memory paradigms and identified selective deficits in the consolidation and reconsolidation of hippocampal-dependent fear memories as task difficulty and hippocampal demand increase. Electrophysiological, biochemical and electron microscopy analyses were carried out in the dentate gyrus of the hippocampus to explore potential alterations in neuronal functions and structure. In vivo and in vitro electrophysiology revealed impaired synaptic transmission, decreased network excitability and reduced AMPA and NMDA conductance in Rsk2 knockout mice. In the absence of RSK2, standard measures of short-term and long-term potentiation (LTP) were normal, however LTP-induced CREB phosphorylation and expression of the transcription factors EGR1/ZIF268 were reduced and that of the scaffolding protein SHANK3 was blocked, indicating impaired activity-dependent gene regulation. At the structural level, the density of perforated and non-perforated synapses and of multiple spine boutons was not altered, however, a clear enlargement of spine neck width and post-synaptic densities indicates altered synapse ultrastructure. These findings show that RSK2 loss-of-function is associated in the dentate gyrus with multi-level alterations that encompass modifications of glutamate receptor channel properties, synaptic transmission, plasticity-associated gene expression and spine morphology, providing novel insights into the mechanisms contributing to cognitive impairments in CLS.
Collapse
Affiliation(s)
- Elise Morice
- Centre de Neurosciences Paris-Sud, CNRS, Orsay, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Grashow R, Miller MW, McKinney A, Nie LH, Sparrow D, Hu H, Weisskopf MG. Lead exposure and fear-potentiated startle in the VA Normative Aging Study: a pilot study of a novel physiological approach to investigating neurotoxicant effects. Neurotoxicol Teratol 2013; 38:21-8. [PMID: 23603705 DOI: 10.1016/j.ntt.2013.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 12/12/2012] [Revised: 04/05/2013] [Accepted: 04/08/2013] [Indexed: 11/29/2022]
Abstract
BACKGROUND Physiologically-based indicators of neural plasticity in humans could provide mechanistic insights into toxicant actions on learning in the brain, and perhaps prove more objective and sensitive measures of such effects than other methods. OBJECTIVES We explored the association between lead exposure and classical conditioning of the acoustic startle reflex (ASR)-a simple form of associative learning in the brain-in a population of elderly men. Fifty-one men from the VA Normative Aging Study with cumulative bone lead exposure measurements made with K-X-Ray-Fluorescence participated in a fear-conditioning protocol. RESULTS The mean age of the men was 75.5years (standard deviation [sd]=5.9) and mean patella lead concentration was 22.7μg/g bone (sd=15.9). Baseline ASR eyeblink response decreased with age, but was not associated with subsequent conditioning. Among 37 men with valid responses at the end of the protocol, higher patella lead was associated with decreased awareness of the conditioning contingency (declarative learning; adjusted odds ratio [OR] per 20μg/g patella lead=0.91, 95% confidence interval [CI]: 0.84, 0.99, p=0.03). Eyeblink conditioning (non-declarative learning) was 0.44sd less (95% CI: -0.91, 0.02; p=0.06) per 20μg/g patella lead after adjustment. Each result was stronger when correcting for the interval between lead measurement and startle testing (awareness: OR=0.88, 95% CI: 0.78, 0.99, p=0.04; conditioning: -0.79sd less, 95% CI: -1.56, 0.03, p=0.04). CONCLUSIONS This initial exploration suggests that lead exposure interferes with specific neural mechanisms of learning and offers the possibility that the ASR may provide a new approach to physiologically explore the effects of neurotoxicant exposures on neural mechanisms of learning in humans with a paradigm that is directly comparable to animal models.
Collapse
Affiliation(s)
- Rachel Grashow
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
| | | | | | | | | | | | | |
Collapse
|