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Ding ZM, Neslund EM, Sun D, Tan X. Methoxsalen inhibits the acquisition of nicotine self-administration: attenuation by cotinine replacement in male rats. Nicotine Tob Res 2024:ntae063. [PMID: 38513068 DOI: 10.1093/ntr/ntae063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Indexed: 03/23/2024]
Abstract
INTRODUCTION Cigarette smoking remains the leading preventable cause of disease and death. Nicotine is the primary reinforcing ingredient in cigarettes sustaining addiction. Cotinine is the major metabolite of nicotine that produces a myriad of neurobehavioral effects. Previous studies showed that cotinine supported self-administration in rats and rats with a history of cotinine self-administration exhibited relapse-like drug-seeking behavior, suggesting that cotinine may also be reinforcing. To date, whether cotinine may contribute to nicotine reinforcement remains unknown. Nicotine metabolism is mainly catalyzed by hepatic CYP2B1/2 enzymes in rats and methoxsalen is a potent CYP2B1/2 inhibitor. METHODS The study examined nicotine metabolism, self-administration, and locomotor activity. The hypothesis is that methoxsalen inhibits nicotine self-administration and cotinine replacement attenuates the inhibitory effects of methoxsalen in male rats. RESULTS Methoxsalen decreased plasma cotinine levels following a subcutaneous nicotine injection. Repeated daily methoxsalen treatments reduced the acquisition of nicotine self-administration, leading to fewer nicotine infusions, lower nicotine intake, and lower plasma cotinine levels. However, methoxsalen did not alter the maintenance of nicotine self-administration despite a significant reduction of plasma cotinine levels. Cotinine replacement by mixing cotinine with nicotine for self-administration dose-dependently increased plasma cotinine levels and enhanced the acquisition of self-administration. Neither basal nor nicotine-induced locomotor activity was altered by methoxsalen. CONCLUSIONS These results indicate that methoxsalen inhibition of cotinine formation impaired the acquisition of nicotine self-administration, and cotinine replacement attenuated the inhibitory effects of methoxsalen on the acquisition of self-administration, suggesting that cotinine may contribute to the initial development of nicotine reinforcement. IMPLICATIONS Smoking cessation medications targeting nicotine's effects are only moderately effective, making it imperative to better understand the mechanisms of nicotine misuse. Methoxsalen inhibited nicotine metabolism to cotinine and impaired the acquisition of nicotine self-administration. Cotinine replacement restored plasma cotinine and attenuated the methoxsalen inhibition of nicotine self-administration in rats. These results suggest that (1) the inhibition of nicotine metabolism may be a viable strategy in reducing the development of nicotine reinforcement, (2) methoxsalen may be translationally valuable, and (3) cotinine may be a potential pharmacological target for therapeutic development given its important role in the initial development of nicotine reinforcement.
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Affiliation(s)
- Zheng-Ming Ding
- Department of Anesthesiology & Perioperative Medicine, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA
- Department of Pharmacology, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Elizabeth M Neslund
- Department of Anesthesiology & Perioperative Medicine, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Dongxiao Sun
- Department of Pharmacology, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA
- Penn State Mass Spectrometry Core Facility, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Xiaoying Tan
- Department of Anesthesiology & Perioperative Medicine, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA
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2
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Frankot MA, Young ME, Vonder Haar C. Understanding Individual Subject Differences through Large Behavioral Datasets: Analytical and Statistical Considerations. Perspect Behav Sci 2024; 47:225-250. [PMID: 38660505 PMCID: PMC11035513 DOI: 10.1007/s40614-023-00388-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2023] [Indexed: 04/26/2024] Open
Abstract
A core feature of behavior analysis is the single-subject design, in which each subject serves as its own control. This approach is powerful for identifying manipulations that are causal to behavioral changes but often fails to account for individual differences, particularly when coupled with a small sample size. It is more common for other subfields of psychology to use larger-N approaches; however, these designs also often fail to account for the individual by focusing on aggregate-level data only. Moving forward, it is important to study individual differences to identify subgroups of the population that may respond differently to interventions and to improve the generalizability and reproducibility of behavioral science. We propose that large-N datasets should be used in behavior analysis to better understand individual subject variability. First, we describe how individual differences have been historically treated and then outline practical reasons to study individual subject variability. Then, we describe various methods for analyzing large-N datasets while accounting for the individual, including correlational analyses, machine learning, mixed-effects models, clustering, and simulation. We provide relevant examples of these techniques from published behavioral literature and from a publicly available dataset compiled from five different rat experiments, which illustrates both group-level effects and heterogeneity across individual subjects. We encourage other behavior analysts to make use of the substantial advancements in online data sharing to compile large-N datasets and use statistical approaches to explore individual differences.
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Affiliation(s)
- Michelle A. Frankot
- Injury and Recovery Laboratory, Department of Psychology, West Virginia University, Morgantown, WV USA
- Injury and Recovery Laboratory, Department of Neuroscience, Ohio State University, 460 West 12th Avenue, Columbus, OH 43210 USA
| | - Michael E. Young
- Department of Psychological Sciences, Kansas State University, Manhattan, KS USA
| | - Cole Vonder Haar
- Injury and Recovery Laboratory, Department of Psychology, West Virginia University, Morgantown, WV USA
- Injury and Recovery Laboratory, Department of Neuroscience, Ohio State University, 460 West 12th Avenue, Columbus, OH 43210 USA
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3
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Frankot M, Mueller PM, Young ME, Vonder Haar C. Statistical power and false positive rates for interdependent outcomes are strongly influenced by test type: Implications for behavioral neuroscience. Neuropsychopharmacology 2023; 48:1612-1622. [PMID: 37142665 PMCID: PMC10516944 DOI: 10.1038/s41386-023-01592-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 03/23/2023] [Accepted: 04/20/2023] [Indexed: 05/06/2023]
Abstract
Statistical errors in preclinical science are a barrier to reproducibility and translation. For instance, linear models (e.g., ANOVA, linear regression) may be misapplied to data that violate assumptions. In behavioral neuroscience and psychopharmacology, linear models are frequently applied to interdependent or compositional data, which includes behavioral assessments where animals concurrently choose between chambers, objects, outcomes, or types of behavior (e.g., forced swim, novel object, place/social preference). The current study simulated behavioral data for a task with four interdependent choices (i.e., increased choice of a given outcome decreases others) using Monte Carlo methods. 16,000 datasets were simulated (1000 each of 4 effect sizes by 4 sample sizes) and statistical approaches evaluated for accuracy. Linear regression and linear mixed effects regression (LMER) with a single random intercept resulted in high false positives (>60%). Elevated false positives were attenuated in an LMER with random effects for all choice-levels and a binomial logistic mixed effects regression. However, these models were underpowered to reliably detect effects at common preclinical sample sizes. A Bayesian method using prior knowledge for control subjects increased power by up to 30%. These results were confirmed in a second simulation (8000 datasets). These data suggest that statistical analyses may often be misapplied in preclinical paradigms, with common linear methods increasing false positives, but potential alternatives lacking power. Ultimately, using informed priors may balance statistical requirements with ethical imperatives to minimize the number of animals used. These findings highlight the importance of considering statistical assumptions and limitations when designing research studies.
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Affiliation(s)
- Michelle Frankot
- Injury and Recovery Laboratory, Department of Neuroscience, Ohio State University, Columbus, OH, USA
- Department of Psychology, West Virginia University, Morgantown, WV, USA
| | - Peyton M Mueller
- Injury and Recovery Laboratory, Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Michael E Young
- Department of Psychological Sciences, Kansas State University, Manhattan, KS, USA
| | - Cole Vonder Haar
- Injury and Recovery Laboratory, Department of Neuroscience, Ohio State University, Columbus, OH, USA.
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4
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Inayat S, McAllister BB, Chang H, Lacoursiere SG, Whishaw IQ, Sutherland RJ, Mohajerani MH. Weak-hyperactive hippocampal CA1 neurons in the prodromal stage of Alzheimer's disease in hybrid App NL-G-F/NL-G-F × Thy1-GCaMP6s +/- mice suggest disrupted plasticity. Neurobiol Aging 2023; 130:154-171. [PMID: 37531809 DOI: 10.1016/j.neurobiolaging.2023.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 05/13/2023] [Accepted: 06/03/2023] [Indexed: 08/04/2023]
Abstract
This study investigated the impact of familial Alzheimer's disease (AD)-linked amyloid precursor protein (App) mutations on hippocampal CA1 neuronal activity and function at an early disease stage in AppNL-G-F/NL-G-F × Thy1-GCaMP6s+/- (A-TG) mice using calcium imaging. Longitudinal assessment of spatial behavior at 12 and 18 months of age identified an early disease stage at 12 months when there was significant amyloid beta pathology with mild behavioral deficits. Hippocampal CA1 neuronal activity and event-related encoding of distance and time were therefore assessed at 12 months of age in several configurations of an air-induced running task to assess the dynamics of cellular activity. Neurons in A-TG mice displayed diminished (weaker) and more frequent (hyperactive) neuronal firing that was more pronounced during movement compared to immobility. Responsive neurons showed configuration-specific deficits in distance and time encoding with impairment in adapting their responses to changing configurations. These results suggest that at an early stage of AD in the absence of full-blown behavioral deficits, weak-hyperactive neuronal activity may induce impairments in sensory perception of changing environments.
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Affiliation(s)
- Samsoon Inayat
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.
| | - Brendan B McAllister
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - HaoRan Chang
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Sean G Lacoursiere
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Ian Q Whishaw
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Robert J Sutherland
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Majid H Mohajerani
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.
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5
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Strain differences in performance of alternation patterns between C57BL/6 and CF1 mice. LEARNING AND MOTIVATION 2021. [DOI: 10.1016/j.lmot.2021.101761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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6
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Maher EE, Overby PF, Bull AH, Beckmann JS, Leyrer-Jackson JM, Koebele SV, Bimonte-Nelson HA, Gipson CD. Natural and synthetic estrogens specifically alter nicotine demand and cue-induced nicotine seeking in female rats. Neuropharmacology 2021; 198:108756. [PMID: 34416269 DOI: 10.1016/j.neuropharm.2021.108756] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/05/2021] [Accepted: 08/14/2021] [Indexed: 11/17/2022]
Abstract
Women have more difficulty maintaining smoking cessation than men, and experience greater withdrawal symptomatology as well as higher prevalence of relapse. Further, currently available treatments for smoking cessation, such as the nicotine patch and varenicline, have been shown to be less effective in women. Fluctuations in ovarian hormones across the menstrual cycle can affect craving and smoking relapse propensity. In addition, many women who smoke use some form of oral contraceptives, which most often contain ethinyl estradiol (EE), a synthetic, orally bio-available estrogen that is currently prescribed to women chronically and has been shown to alter smoking reward in women. The current study examined the impact of 17β-estradiol (E2), the prominent endogenous form of the steroid hormone estrogen, as well as EE, on nicotine self-administration, demand, and reinstatement following ovariectomy (OVX) or sham surgery. OVX vehicle-treated female rats consumed less nicotine, had lower intensity of demand, and reinstated less compared to sham vehicle-treated female rats. OVX-E2 and OVX-EE treatment groups showed a rebound of nicotine intake later in training, and Q0 levels of consumption were partially rescued in both groups. Further, E2 but not EE reversed the abolishment of reinstated nicotine seeking induced by OVX. Taken together, these results demonstrate that natural and synthetic estrogens play a critical role in mediating the neurobehavioral effects of nicotine, and future studies are essential for our understanding of how synthetic hormones contained within oral contraceptives interact with smoking.
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Affiliation(s)
- Erin E Maher
- Department of Family and Community Medicine, University of Kentucky, Lexington, KY, USA
| | - Paula F Overby
- Department of Psychology, Arizona State University, Tempe, AZ, USA
| | - Amanda H Bull
- Department of Psychology, Arizona State University, Tempe, AZ, USA
| | - Joshua S Beckmann
- Department of Psychology, University of Kentucky, Lexington, KY, USA
| | | | - Stephanie V Koebele
- Department of Psychology, Arizona State University, Tempe, AZ, USA; Arizonia Alzheimer's Consortium, Phoenix, AZ, USA
| | - Heather A Bimonte-Nelson
- Department of Psychology, Arizona State University, Tempe, AZ, USA; Arizonia Alzheimer's Consortium, Phoenix, AZ, USA
| | - Cassandra D Gipson
- Department of Family and Community Medicine, University of Kentucky, Lexington, KY, USA.
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Smith AP, Beckmann JS. Quantifying value-based determinants of drug and non-drug decision dynamics. Psychopharmacology (Berl) 2021; 238:2047-2057. [PMID: 33839902 PMCID: PMC8529627 DOI: 10.1007/s00213-021-05830-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 03/15/2021] [Indexed: 01/17/2023]
Abstract
RATIONALE A growing body of research suggests that substance use disorder (SUD) may be characterized as disorders of decision making. However, drug choice studies assessing drug-associated decision making often lack more complex and dynamic conditions that better approximate contexts outside the laboratory and may lead to incomplete conclusions regarding the nature of drug-associated value. OBJECTIVES The current study assessed isomorphic (choice between identical food options) and allomorphic (choice between remifentanil [REMI] and food) choice across dynamically changing reward probabilities, magnitudes, and differentially reward-predictive stimuli in male rats to better understand determinants of drug value. Choice data were analyzed at aggregate and choice-by-choice levels using quantitative matching and reinforcement learning (RL) models, respectively. RESULTS Reductions in reward probability or magnitude independently reduced preferences for food and REMI commodities. Inclusion of reward-predictive cues significantly increased preference for food and REMI rewards. Model comparisons revealed that reward-predictive stimuli significantly altered the economic substitutability of food and REMI rewards at both levels of analysis. Furthermore, model comparisons supported the reformulation of reward value updating in RL models from independent terms to a shared, relative term, more akin to matching models. CONCLUSIONS The results indicate that value-based quantitative choice models can accurately capture choice determinants within complex decision-making contexts and corroborate drug choice as a multidimensional valuation process. Collectively, the present study indicates commonalities in decision-making for drug and non-drug rewards, validates the use of economic-based SUD therapies (e.g., contingency management), and implicates the neurobehavioral processes underlying drug-associated decision-making as a potential avenue for future SUD treatment.
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Affiliation(s)
- Aaron P Smith
- Cofrin Logan Center for Addiction Research and Treatment, University of Kansas, Lawrence, KS, USA
| | - Joshua S Beckmann
- Department of Psychology, University of Kentucky, Lexington, KY, USA.
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8
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Rai SP, Krohn M, Pahnke J. Early Cognitive Training Rescues Remote Spatial Memory but Reduces Cognitive Flexibility in Alzheimer's Disease Mice. J Alzheimers Dis 2021; 75:1301-1317. [PMID: 32417783 PMCID: PMC7369118 DOI: 10.3233/jad-200161] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Spatial memory dysfunction has been demonstrated in mouse models of Alzheimer's disease (AD) which is consistent with the clinical finding that the early signature of AD includes difficulties in the formation and/or storage of a memory. A stored memory-a long term memory-can be modulated via process called as memory retrieval that can either lead toward memory reconsolidation or even memory extinction. OBJECTIVE We aim to shed light on the fate of the spatial memory during memory reactivation and memory extinction using a water maze task. METHODS In Set-up I, we trained 3-month-old mice (wild-type mice and mice with cerebral β-amyloidosis) and assessed the fate of remote memory after four months of retention interval (RI). In Set-up II, we performed an early-extensive training at 2 months of age, retrained the same mice at 3 months of age, introduced four months of RI, and finally assessed remote spatial memory at 7 months of age. RESULTS We find in β-amyloidosis mice that memory reactivation problems were detectable at 7 months of age and were alleviated by cognitive overtraining. Similarly, forgetting of remote spatial memory was also minimized by cognitive overtraining. Finally, we show that the cognitive training facilitates the recovery of the reactivated spatial memory while reducing the ability to form new spatial memory in AD mice. CONCLUSION This result may explain the rationality behind the cognitive reserve observed in AD patients and elderly with severe β-amyloidosis not corresponding to the actual low dementia symptoms.
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Affiliation(s)
- Surya Prakash Rai
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - Markus Krohn
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway.,Current address: University of Lübeck, Lübeck, Germany
| | - Jens Pahnke
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway.,LIED, University of Lübeck, Lübeck, Germany.,Department of Pharmacology, Faculty of Medicine, University of Latvia, Rīga, Latvia.,Department for Bioorganic Chemistry, Leibniz-Institute of Plant Biochemistry, Halle, Germany
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9
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Mixed effects modeling of Morris water maze data revisited: Bayesian censored regression. Learn Behav 2021; 49:307-320. [PMID: 33619694 DOI: 10.3758/s13420-020-00457-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2020] [Indexed: 11/08/2022]
Abstract
Young, Clark, Goffus, and Hoane (Learning and Motivation, 40(2), 160-177, 2009) documented significant advantages of linear and nonlinear mixed-effects modeling in the analysis of Morris water maze data. However, they also noted a caution regarding the impact of the common practice of ending a trial when the rat had not reached the platform by a preestablished deadline. The present study revisits their conclusions by considering a new approach that involves multilevel (i.e., mixed effects) censored generalized linear regression using Bayesian analysis. A censored regression explicitly models the censoring created by prematurely ending a trial, and the use of generalized linear regression incorporates the skewed distribution of latency data as well as the nonlinear relationships this can produce. This approach is contrasted with a standard multilevel linear and nonlinear regression using two case studies. The censored generalized linear regression better models the observed relationships, but the linear regression created mixed results and clearly resulted in model misspecification.
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10
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Yates JR, Horchar MJ, Ellis AL, Kappesser JL, Mbambu P, Sutphin TG, Dehner DS, Igwe HO, Wright MR. Differential effects of glutamate N-methyl-D-aspartate receptor antagonists on risky choice as assessed in the risky decision task. Psychopharmacology (Berl) 2021; 238:133-148. [PMID: 32936321 PMCID: PMC7796939 DOI: 10.1007/s00213-020-05664-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/10/2020] [Indexed: 12/15/2022]
Abstract
RATIONALE Risky choice can be measured using the risky decision task (RDT). In the RDT, animals choose between a large, risky option that is paired with probabilistic foot shock and a small, safe option that is never paired with shock. To date, studies examining the neurochemical basis of decision-making in the RDT have focused primarily on the dopaminergic system but have not focused on the glutamatergic system, which has been implicated in risky decision-making. OBJECTIVES Because glutamate is known to play a critical role in decision-making, we wanted to determine the contribution of the glutamatergic system to performance in the RDT. METHODS In the experiment, 32 rats (16 male; 16 female) were tested in the RDT. The probability of receiving a foot shock increased across the session (ascending schedule) for half of the rats but decreased across the session (descending schedule) for half of the rats. Following training, rats received injections of the N-methyl-D-aspartate (NMDA) receptor competitive antagonist CGS 19755 (0, 1.0, 2.5, 5.0 mg/kg; s.c.) and the GluN2B-selective antagonist Ro 63-1908 (0, 0.1, 0.3, 1.0 mg/kg; s.c.). RESULTS CGS 19755 (2.5 and 5.0 mg/kg) increased risky choice in males and females trained on the ascending schedule. Ro 63-1908 (1.0 mg/kg) decreased risky choice, but only in male rats trained on the ascending schedule. CONCLUSIONS Although NMDA receptor antagonists differentially alter risky choice in the RDT, the current results show that NMDA receptors are an important mediator of decision-making involving probabilistic delivery of positive punishment.
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Affiliation(s)
- Justin R Yates
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA.
| | - Matthew J Horchar
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Alexis L Ellis
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Joy L Kappesser
- Department of Biological Sciences, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Prodiges Mbambu
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Tanner G Sutphin
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Destiny S Dehner
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Hephzibah O Igwe
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Makayla R Wright
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
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Rai SP, Bascuñana P, Brackhan M, Krohn M, Möhle L, Paarmann K, Pahnke J. Detection and Prediction of Mild Cognitive Impairment in Alzheimer's Disease Mice. J Alzheimers Dis 2020; 77:1209-1221. [PMID: 32831204 PMCID: PMC7683054 DOI: 10.3233/jad-200675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background: The recent failure of clinical trials to treat Alzheimer’s disease (AD) indicates that the current approach of modifying disease is either wrong or is too late to be efficient. Mild cognitive impairment (MCI) denotes the phase between the preclinical phase and clinical overt dementia. AD mouse models that overexpress human amyloid-β (Aβ) are used to study disease pathogenesis and to conduct drug development/testing. However, there is no direct correlation between the Aβ deposition, the age of onset, and the severity of cognitive dysfunction. Objective: To detect and predict MCI when Aβ plaques start to appear in the hippocampus of an AD mouse. Methods: We trained wild-type and AD mice in a Morris water maze (WM) task with different inter-trial intervals (ITI) at 3 months of age and assessed their WM performance. Additionally, we used a classification algorithm to predict the genotype (APPtg versus wild-type) of an individual mouse from their respective WM data. Results: MCI can be empirically detected using a short-ITI protocol. We show that the ITI modulates the spatial learning of AD mice without affecting the formation of spatial memory. Finally, a simple classification algorithm such as logistic regression on WM data can give an accurate prediction of the cognitive dysfunction of a specific mouse. Conclusion: MCI can be detected as well as predicted simultaneously with the onset of Aβ deposition in the hippocampus in AD mouse model. The mild cognitive impairment prediction can be used for assessing the efficacy of a treatment.
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Affiliation(s)
- Surya Prakash Rai
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - Pablo Bascuñana
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - Mirjam Brackhan
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - Markus Krohn
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - Luisa Möhle
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - Kristin Paarmann
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - Jens Pahnke
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway.,LIED, University of Lübeck, Lübeck, Germany.,Department of Pharmacology, Faculty of Medicine, University of Latvia, Rīga, Latvia.,Department for Bioorganic Chemistry, Leibniz-Institute of Plant Biochemistry, Halle, Germany
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12
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Obesity Drives Delayed Infarct Expansion, Inflammation, and Distinct Gene Networks in a Mouse Stroke Model. Transl Stroke Res 2020; 12:331-346. [PMID: 32588199 DOI: 10.1007/s12975-020-00826-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 05/11/2020] [Accepted: 06/03/2020] [Indexed: 01/11/2023]
Abstract
Obesity is associated with chronic peripheral inflammation, is a risk factor for stroke, and causes increased infarct sizes. To characterize how obesity increases infarct size, we fed a high-fat diet to wild-type C57BL/6J mice for either 6 weeks or 15 weeks and then induced distal middle cerebral artery strokes. We found that infarct expansion happened late after stroke. There were no differences in cortical neuroinflammation (astrogliosis, microgliosis, or pro-inflammatory cytokines) either prior to or 10 h after stroke, and also no differences in stroke size at 10 h. However, by 3 days after stroke, animals fed a high-fat diet had a dramatic increase in microgliosis and astrogliosis that was associated with larger strokes and worsened functional recovery. RNA sequencing revealed a dramatic increase in inflammatory genes in the high-fat diet-fed animals 3 days after stroke that were not present prior to stroke. Genetic pathways unique to diet-induced obesity were primarily related to adaptive immunity, extracellular matrix components, cell migration, and vasculogenesis. The late appearance of neuroinflammation and infarct expansion indicates that there may be a therapeutic window between 10 and 36 h after stroke where inflammation and obesity-specific transcriptional programs could be targeted to improve outcomes in people with obesity and stroke.
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13
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Garcia EJ, Cain ME. Environmental enrichment and a selective metabotropic glutamate receptor 2/3 (mGluR 2/3) agonist suppress amphetamine self-administration: Characterizing baseline differences. Pharmacol Biochem Behav 2020; 192:172907. [PMID: 32179027 DOI: 10.1016/j.pbb.2020.172907] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/19/2020] [Accepted: 03/12/2020] [Indexed: 01/26/2023]
Abstract
A challenge for developing effective treatments for substance use disorders (SUDs) is understanding how environmental variables alter the efficacy of therapeutics. Environmental enrichment (EC) enhances brain development and protects against behaviors associated with drug abuse vulnerability when compared to rats reared in isolation (IC) or standard conditions (SC). EC rearing enhances the expression and function of metabotropic glutamate receptor2/3 (mGlurR2/3) and activating mGluR2/3 reduces psychostimulant self-administration (SA). However, the ability for mGluR2/3 activation to suppress amphetamine (AMP) SA in differentially reared rats is not determined. Therefore, we tested the hypothesis EC reduces AMP (SA) by augmenting mGluR2/3 function. At postnatal day 21, male Sprague-Dawley rats were assigned to EC, IC, or SC environments for 30 days. Then, they acquired AMP SA and were moved to a progressive ratio (PR) schedule of reinforcement. EC, IC, and SC rats were pretreated with LY379268 (vehicle, 0.3 and 1 mg/kg), a selective mGluR2/3 agonist, before PR behavioral sessions. Linear mixed effects analysis determined EC rats had reduced motivation for AMP SA when compared to IC or SC rats and that LY379268 dose-dependently suppressed AMP SA, but there was no evidence of an interaction. Cumming/Gardner-Altman estimation plots illustrate that the 0.3 mg/kg dose suppressed infusions in EC rats while the 1 mg/kg dose suppressed infusions in SC rats. LY379268 was incapable of suppressing the motivation for AMP SA in IC rats. Controlling for baseline differences in differentially reared rats remains a challenge. Normalizing to a baseline introduced error which is illustrated in the precision of the estimated effect size differences. The data indicate that environmental enrichment enhances the ability of a selective mGluR2/3 agonist to suppress AMP SA and indicates the functional status of the mGluR2/3 is formed during development. Therefore, environmental history must be considered when evaluating pharmacological therapeutics particularly those aimed at the mGluR2/3.
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Affiliation(s)
- Erik J Garcia
- Department of Psychological Sciences, Kansas State University, United States of America
| | - Mary E Cain
- Department of Psychological Sciences, Kansas State University, United States of America.
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Toward isolating reward changes in diet-induced obesity: A demand analysis. Physiol Behav 2020; 213:112729. [PMID: 31678579 DOI: 10.1016/j.physbeh.2019.112729] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/29/2019] [Accepted: 10/29/2019] [Indexed: 11/22/2022]
Abstract
Although hormonal and metabolic factors are well known to influence obesity, recent evidence suggests that obesity may be influenced also by changes in reward sensitivity akin to that seen in other 'reward pathologies', like substance use disorders. The current study sought to isolate changes in reward that may occur after the onset of diet-induced obesity by characterizing the economic demand for caloric (sucrose) and non-caloric (saccharin) reinforcers in a preclinical model of diet-induced obesity (DIO). We utilized economic demand analysis to measure baseline demand intensity (Q0) and demand elasticity (α) for sucrose and saccharin reinforcers in rats. After baseline measures were collected, rats were assigned randomly to a high-fat (HF) diet or low-fat (LF) control diet. After 8-weeks of diet exposure, HF rats were divided into obesity-resistant (OR) or obesity-prone (OP) groups based on weight after the 8-week HF diet exposure. Post-DIO demand data for each reinforcer were reassessed. At baseline, rats had higher demand intensity and lower elasticity for sucrose compared to saccharin. After 8-weeks of the high-fat diet, OP rats had significantly greater weight gain and lower demand elasticity for sucrose and saccharin and higher demand intensity for saccharin. The changes in sucrose and saccharin elasticity suggest that DIO-induced changes in food-related behavior are associated with changes in reward processes. The changes in demand intensity for saccharin suggest that demand intensity, as a measure of 'set point', is not directly linked to metabolic processes. The current study shows that microeconomic theory and demand analysis is able to isolate independent aspects of diet-induced reward changes related to caloric and non-caloric reinforcers.
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Gender, videogames and navigation in virtual space. Acta Psychol (Amst) 2019; 199:102895. [PMID: 31377309 DOI: 10.1016/j.actpsy.2019.102895] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 06/03/2019] [Accepted: 07/16/2019] [Indexed: 12/16/2022] Open
Abstract
Spatial abilities associated with success in educational and occupational fields of Science, Technology, Engineering, and Mathematics (STEM) have been repeatedly shown to be gendered, with males demonstrating measurably better spatial abilities than females. Less is known about why this is, or about how experience with spatial systems (videogames, for example) affects these abilities. We conducted two experiments with 82 participants with varying degrees of videogame experience on measures of mental rotation, spatial learning, and spatial memory. Spatial learning and memory were tested in a Virtual Morris Water Maze. In the first experiment, the maze lacked proximal landmarks. Males proved faster and more accurate than females in learning the location of the hidden platform. As predicted males also outperformed females in mental rotation abilities. Mental rotation correlated with performance in the virtual maze, indicating that in the absence of proximal landmarks, participants relied on strategies requiring mental rotation. Experienced 3D videogame players did not demonstrate superior spatial learning and memory, but performed better than novices in mental rotation. In the second experiment, the maze had proximal cues, in the form of landmarks on the circumference of the virtual pool, and gender-based differences in navigational performance significantly diminished. Under these changed environmental conditions, mental rotation ability did not correlate with performance in the VMWM, suggesting that given proximal cues, the need for mental rotation diminishes. Differences between videogame novices and experts also decreased when proximal cues were provided. Females in particular obtained more discernible benefits from videogame experience. Together, these experiments reveal how the spatial abilities and strategies used to solve the Morris maze task vary with environmental design. Given the structural similarities between the virtual maze and videogame environments, these results offer insight into how spatial experience gained through videogame playing can affect aspects of spatial cognition, and can help identify design elements that contribute to their improvement.
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Yates JR, Bardo MT, Beckmann JS. Environmental enrichment and drug value: a behavioral economic analysis in male rats. Addict Biol 2019; 24:65-75. [PMID: 29178664 DOI: 10.1111/adb.12581] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 10/16/2017] [Accepted: 10/23/2017] [Indexed: 01/19/2023]
Abstract
Rats raised in an enriched condition (EC) show decreased stimulant self-administration relative to rats reared in an isolated condition (IC). However, few studies have examined the behavioral mechanisms underlying this environment-induced difference in self-administration. Because economic demand for drugs of abuse predicts addiction-like behavior in both humans and animals, we applied a behavioral economic analysis to cocaine self-administration data in EC and IC rats. During cocaine self-administration, the dose decreased across blocks of trials (0.75-0.003 mg/kg/inf), which allowed for a determination of demand intensity and demand elasticity. Demand intensity did not differ between EC and IC rats; however, cocaine was more elastic in EC rats relative to IC rats (i.e. EC rats were less willing to respond for cocaine as the unit price increased). When EC rats were placed in an isolated condition, demand elasticity decreased, whereas elasticity increased for IC rats placed in an enriched condition. Additionally, we applied behavioral economic analyses to previously published self-administration data and found that our results replicate past findings with cocaine and methylphenidate. To determine if differences in demand elasticity are specific to drug reinforcement, a separate group of rats was tested in sucrose or saccharin self-administration. Results showed that sucrose and saccharin were more elastic in EC rats relative to IC rats, and demand intensity was lower for saccharin in EC rats relative to IC rats. Overall, drug and nondrug reinforcers are more elastic in EC rats, which may account for the protective effects of environmental enrichment against stimulant self-administration.
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Affiliation(s)
- Justin R. Yates
- Department of Psychological Science; Northern Kentucky University; Highland Heights KY USA
- Department of Psychology; University of Kentucky; Lexington KY USA
| | - Michael T. Bardo
- Department of Psychology; University of Kentucky; Lexington KY USA
- Center for Drug Abuse Research Translation; University of Kentucky; Lexington KY USA
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Yates JR, Gunkel BT, Rogers KK, Breitenstein KA, Hughes MN, Johnson AB, Sharpe SM. Effects of N-methyl-d-aspartate receptor (NMDAr) uncompetitive antagonists in a delay discounting paradigm using a concurrent-chains procedure. Behav Brain Res 2018; 349:125-129. [PMID: 29604367 DOI: 10.1016/j.bbr.2018.03.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 03/15/2018] [Accepted: 03/23/2018] [Indexed: 02/05/2023]
Abstract
Impulsive choice is often assessed in rodents using a delay discounting (DD) paradigm in which the delay to a large reinforcer (LR) increases across the session. This procedure allows one to test the effects of pharmacological manipulations within a single session. Because discounting is influenced by sensitivity to reinforcer magnitude (SRM) and sensitivity to delayed reinforcement (SDR), applying quantitative analyses (e.g., fitting hyperbolic function) is important for determining the precise behavioral mechanisms being altered following drug administration. One caveat to this approach is that observing increases in SMR/SDR can be difficult (e.g., most rats choose the LR when its delivery is immediate, whereas some rats may show exclusive preference for the small reinforcer [SR] when a delay on the LR is imposed). We utilized a variant of a concurrent-chains procedure in which rats (n = 8) could not show exclusive preference for either reinforcer, thus allowing one to observe increases/decreases in responding at each delay. The NMDAr antagonists MK-801 (0, 0.003, 0.01, 0.03 mg/kg), ketamine (0, 1.0, 5.0, 10.0 mg/kg), and memantine (0, 2.5, 5.0, 7.5 mg/kg) were administered following baseline training because this receptor has recently been implicated in DD. MK-801 (0.03 mg/kg) decreased SRM and SDR. Memantine (7.5 mg/kg) decreased SRM only. These results show that this variant of the concurrent-chains procedure can be used to study the effects of pharmacological manipulations on distinct aspects of DD.
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Affiliation(s)
- Justin R Yates
- Department of Psychological Science, Northern Kentucky University, USA.
| | - Benjamin T Gunkel
- Department of Psychological Science, Northern Kentucky University, USA
| | | | | | - Mallory N Hughes
- Department of Psychological Science, Northern Kentucky University, USA
| | - Anthony B Johnson
- Department of Psychological Science, Northern Kentucky University, USA
| | - Sara M Sharpe
- Department of Psychological Science, Northern Kentucky University, USA
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Lazareva OF, McInnerney J, Williams T. Implicit relational learning in a multiple-object tracking task. Behav Processes 2018; 152:26-36. [DOI: 10.1016/j.beproc.2018.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 10/17/2022]
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Acerbo MJ, Lazareva OF. Pharmacological manipulation of GABA activity in nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS) impairs figure-ground discrimination in pigeons: Running head: SP/IPS in figure-ground segregation. Behav Brain Res 2018; 344:1-8. [PMID: 29408282 DOI: 10.1016/j.bbr.2018.01.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 01/09/2018] [Accepted: 01/30/2018] [Indexed: 11/18/2022]
Abstract
Figure-ground segregation is a fundamental visual ability that allows an organism to separate an object from its background. Our earlier research has shown that nucleus rotundus (Rt), a thalamic nucleus processing visual information in pigeons, together with its inhibitory complex, nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS), are critically involved in figure-ground discrimination (Acerbo et al., 2012; Scully et al., 2014). Here, we further investigated the role of SP/IPS by conducting bilateral microinjections of GABAergic receptor antagonist and agonists (bicuculline and muscimol, respectively) and non-NMDA glutamate receptor antagonist (CNQX) after the pigeons mastered figure-ground discrimination task. We used two doses of each drug (bicuculline: 0.1 mM and 0.05 mM; muscimol: 4.4 mM and 8.8 mM; CNQX: 2.15 mM and 4.6 mM) in a within-subject design, and alternated drug injections with baseline (ACSF). The order of injections was randomized across birds to reduce potential carryover effects. We found that a low dose of bicuculline produced a decrement on figure trials but not on background trials, whereas a high dose impaired performance on background trials but not on figure trials. Muscimol produced an equivalent, dose-dependent impairment on both types of trials. Finally, CNQX had no consistent effect at either dose. Together, these results further confirm our earlier hypothesis that inhibitory projections from SP to Rt modulate figure-ground discrimination, and suggest that the Rt and the SP/IPS provide a plausible substrate that could perform figure-ground segregation in avian brain.
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Daniels CW, Overby PF, Sanabria F. Between-session memory degradation accounts for within-session changes in fixed-interval performance. Behav Processes 2018; 153:31-39. [PMID: 29729953 DOI: 10.1016/j.beproc.2018.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/15/2018] [Accepted: 05/02/2018] [Indexed: 01/02/2023]
Abstract
A common assumption in the study of fixed-interval (FI) timing is that FI performance is largely stable within sessions, once it is stable between sessions. Within-session changes in FI performance were examined in published data (Daniels and Sanabria, 2017), wherein some rats were trained on a FI 30-s schedule of food reinforcement (FI30) and others on a FI 90-s schedule (FI90). Following stability, FI90 rats were pre-fed for five sessions. Response rates declined as a function of trial, due more to latency lengthening than to run-rate reduction. Latencies were best described by a dynamic gamma-exponential mixture distribution, in which latency lengthening was driven by the growth of the criterion pulse count for a response and not by a reduction in the speed of an endogenous clock. The speed of the clock was selectively sensitive to the length of the FI; the prevalence and length of exponentially-distributed latencies were selectively sensitive to pre-feeding. These findings reveal (a) that parameters governing FI latencies are selectively sensitive to a range of manipulations, (b) a potential degradation of the criterion pulse count between consecutive sessions, and (c) a subsequent recovery of the criterion pulse count within sessions.
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Smith AP, Hofford RS, Zentall TR, Beckmann JS. The role of 'jackpot' stimuli in maladaptive decision-making: dissociable effects of D1/D2 receptor agonists and antagonists. Psychopharmacology (Berl) 2018; 235:1427-1437. [PMID: 29455291 PMCID: PMC7716655 DOI: 10.1007/s00213-018-4851-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 02/05/2018] [Indexed: 01/10/2023]
Abstract
RATIONALE Laboratory experiments often model risk through a choice between a large, uncertain (LU) reward against a small, certain (SC) reward as an index of an individual's risk tolerance. An important factor generally lacking from these procedures are reward-associated cues that may modulate risk preferences. OBJECTIVE We tested whether the addition of cues signaling 'jackpot' wins to LU choices would modulate risk preferences and if these cue effects were mediated by dopaminergic signaling. METHODS Three groups of rats chose between LU and SC rewards for which the LU probability of reward decreased across blocks. The unsignaled group received a non-informative stimulus of trial outcome. The signaled group received a jackpot signal prior to reward delivery and blackout on losses. The signaled-light group received a similar jackpot for wins, but a salient loss signal distinct from the win signal. RESULTS Presenting win signals decreased the discounting of LU value for both signaled groups regardless of loss signal, while the unsignaled group showed discounting similar to previous research without cues. Pharmacological challenges with D1/D2 agonists and antagonists revealed that D1 antagonism increased and decreased sensitives to the relative probability of reward for unsignaled and signaled groups, respectively, while D2 agonists decreased sensitivities to the relative magnitude of reward. CONCLUSION The results highlight how signals predictive of wins can promote maladaptive risk taking in individuals, while loss signals have reduced effect. Additionally, the presence of reward-predictive cues may change the underlying neurobehavioral mechanisms mediating decision-making under risk.
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Affiliation(s)
- Aaron P. Smith
- Department of Psychology, University of Kentucky, Lexington Kentucky, 40506, United States of America
| | - Rebecca S. Hofford
- Department of Psychology, University of Kentucky, Lexington Kentucky, 40506, United States of America
| | - Thomas R. Zentall
- Department of Psychology, University of Kentucky, Lexington Kentucky, 40506, United States of America
| | - Joshua S. Beckmann
- Department of Psychology, University of Kentucky, Lexington Kentucky, 40506, United States of America,correspondence sent to:
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Yates JR. Dissecting drug effects in preclinical models of impulsive choice: emphasis on glutamatergic compounds. Psychopharmacology (Berl) 2018; 235:607-626. [PMID: 29305628 PMCID: PMC5823766 DOI: 10.1007/s00213-017-4825-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 12/27/2017] [Indexed: 01/10/2023]
Abstract
RATIONALE Impulsive choice is often measured with delay discounting paradigms. Because there are multiple discounting procedures, as well as different statistical analyses that can be applied to data generated from these paradigms, there are some inconsistencies in the literature regarding drug effects on impulsive choice. OBJECTIVES The goal of the current paper is to review the methodological and analytic approaches used to measure discounting and to discuss how these differences can account for differential drug effects observed across studies. RESULTS Because some procedures/analyses use a single data point as the dependent variable, changes in this value following pharmacological treatment may be interpreted as alterations in sensitivity to delayed reinforcement, but when other procedures/analyses are used, no changes in behavior are observed. Even when multiple data points are included, some studies show that the statistical analysis (e.g., ANOVA on raw proportion of responses vs. using hyperbolic/exponential functions) can lead to different interpretations. Finally, procedural differences (e.g., delay presentation order, signaling the delay to reinforcement, etc.) in the same discounting paradigm can alter how drugs affect sensitivity to delayed reinforcement. CONCLUSIONS Future studies should utilize paradigms that allow one to observe alterations in responding at each delay (e.g., concurrent-chains schedules). Concerning statistical analyses, using parameter estimates derived from nonlinear functions or incorporating the generalized matching law can allow one to determine if drugs affect sensitivity to delayed reinforcement or impair discrimination of the large and small magnitude reinforcers. Using these approaches can help further our understanding of the neurochemical underpinnings of delay discounting.
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Affiliation(s)
- Justin R Yates
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA.
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Yates JR, Gunkel BT, Rogers KK, Hughes MN, Prior NA. Effects of N-methyl-D-aspartate receptor ligands on sensitivity to reinforcer magnitude and delayed reinforcement in a delay-discounting procedure. Psychopharmacology (Berl) 2017; 234:461-473. [PMID: 27837332 PMCID: PMC5226882 DOI: 10.1007/s00213-016-4469-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 11/02/2016] [Indexed: 11/26/2022]
Abstract
RATIONALE The N-methyl-D-aspartate (NMDA) receptor has been recently identified as an important mediator of impulsive choice, as assessed in delay discounting. Although discounting is independently influenced by sensitivity to reinforcer magnitude and delayed reinforcement, few studies have examined how NMDA receptor ligands differentially affect these parameters. OBJECTIVES The current study examined the effects of various NMDA receptor ligands on sensitivity to reinforcer magnitude and delayed reinforcement in a delay-discounting procedure. METHODS Following behavioral training, rats received treatments of the following NMDA receptor ligands: the uncompetitive antagonists ketamine (0, 1.0, 5.0, or 10.0 mg/kg; i.p.), MK-801 (0, 0.003, 0.01, or 0.03 mg/kg; s.c.), and memantine (0, 2.5, 5.0, or 10.0 mg/kg; i.p.), the competitive antagonist CGS 19755 (0, 5.0, 10.0, or 20.0 mg/kg; s.c.), the non-competitive NR2B subunit-selective antagonist ifenprodil (0, 1.0, 3.0, or 10.0 mg/kg; i.p), and the partial agonist D-cycloserine (0, 3.25, 15.0, or 30.0 mg/kg; s.c.). RESULTS When an exponential model was used to describe discounting, CGS 19755 (5.0 mg/kg) increased impulsive choice without altering sensitivity to reinforcer magnitude. Conversely, ketamine (10.0 mg/kg), memantine (5.0 mg/kg), and ifenprodil (10.0 mg/kg) decreased sensitivity to reinforcer magnitude without altering impulsive choice. MK-801 and D-cycloserine did not alter delay-discounting performance, although two-way ANOVA analyses indicated D-cycloserine (15.0 mg/kg) decreased impulsive choice. CONCLUSIONS The behavioral changes observed in delay discounting following administration of NMDA receptor antagonists do not always reflect an alteration in impulsive choice. These results emphasize the utility in employing quantitative methods to assess drug effects in delay discounting.
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Affiliation(s)
- Justin R Yates
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA.
| | - Benjamin T Gunkel
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Katherine K Rogers
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Mallory N Hughes
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
| | - Nicholas A Prior
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY, 41099, USA
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Hutsell BA, Negus SS, Banks ML. Effects of 21-day d-amphetamine and risperidone treatment on cocaine vs food choice and extended-access cocaine intake in male rhesus monkeys. Drug Alcohol Depend 2016; 168:36-44. [PMID: 27615401 PMCID: PMC5086289 DOI: 10.1016/j.drugalcdep.2016.08.637] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 08/31/2016] [Accepted: 08/31/2016] [Indexed: 11/24/2022]
Abstract
BACKGROUND Clinical trial data suggest amphetamine treatment is most efficacious in moderate to high frequency cocaine users. However, preclinical studies have examined amphetamine treatment effects under relatively limited cocaine access conditions with low to moderate cocaine intakes. This study determined d-amphetamine treatment effects on cocaine self-administration in rhesus monkeys under cocaine access conditions allowing for high daily cocaine intake. For comparison and as a negative control, treatment effects with the antipsychotic risperidone were also examined. METHODS Continuous 21-day treatments with ramping doses of d-amphetamine (days 1-7: 0.032mg/kg/h; days 8-21: 0.1mg/kg/h, i.v.) or risperidone (days 1-7: 0.001mg/kg/h; days 8-14: 0.0032mg/kg/h; days 15-21: 0.0056mg/kg/h, i.v.) were administered to rhesus monkeys (n=4) with daily access to two types of cocaine self-administration sessions: (1) a 2-h 'choice' session with concurrent availability of 1-g food pellets and intravenous cocaine injections (0-0.1mg/kg per injection) and (2) a 20-h 'extended-access' session with 0.1mg/kg per injection cocaine availability. RESULTS Total daily cocaine intake increased >6-fold during extended cocaine access. d-Amphetamine significantly decreased total cocaine intake, but not cocaine vs food choice. In contrast, risperidone did not significantly alter either total cocaine intake or cocaine vs. food choice. CONCLUSIONS These results confirm and extend previous results supporting treatment effectiveness for monoamine releasers, but not dopamine antagonists, to reduce cocaine self-administration. Moreover, these results suggest amphetamine treatment efficacy to decrease preclinical cocaine vs. food choice may depend upon cocaine access conditions.
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Affiliation(s)
| | | | - Matthew L. Banks
- Corresponding author at: Department of Pharmacology and Toxicology, Virginia Commonwealth University, 410 North 12th Street, PO Box 980613, Richmond, VA, 23298, USA. (M.L. Banks)
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Hofford RS, Beckmann JS, Bardo MT. Rearing environment differentially modulates cocaine self-administration after opioid pretreatment: A behavioral economic analysis. Drug Alcohol Depend 2016; 167:89-94. [PMID: 27511893 PMCID: PMC5037017 DOI: 10.1016/j.drugalcdep.2016.07.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/25/2016] [Accepted: 07/26/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND Research has shown that previous experiences during development, especially if stressful, can alter an organism's response to opioids later in life. Given the previous literature on opioid modulation of cocaine self-administration, the current study raised rats in either an enriched condition (EC) or isolated condition (IC) and employed behavioral economics to study the effects of naltrexone and morphine on cocaine self-administration. METHODS EC and IC rats were trained to lever press for cocaine using a within-session demand procedure. This procedure measured cocaine consumption under changing cocaine price by decreasing the dose of cocaine earned throughout a session. Rats were able to self-administer cocaine on a FR1; every 10min the cocaine dose was systematically decreased (0.75-0.003mg/kg/infusion cocaine). After reaching stability on this procedure, rats were randomly pretreated with 0, 0.3, 1, or 3mg/kg naltrexone once every 3days, followed by random pretreatments of 0, 0.3, 1, or 3mg/kg morphine once every 3days. Economic demand functions were fit to each rat's cocaine consumption from each pretreatment, and appropriate mathematical parameters were extracted and analyzed. RESULTS Naltrexone decreased the essential value of cocaine in IC rats only. However, morphine decreased the essential value of cocaine and the consumption of cocaine at zero price in both EC and IC rats. CONCLUSION These results indicate that environmental experiences during development should be considered when determining the efficacy of opioid drugs, especially for the treatment of substance abuse.
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Affiliation(s)
- Rebecca S. Hofford
- Corresponding author: ; 741 S. Limestone, 448 C BBSRB, University of Kentucky, Lexington KY 40536
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Chow JJ, Nickell JR, Darna M, Beckmann JS. Toward isolating the role of dopamine in the acquisition of incentive salience attribution. Neuropharmacology 2016; 109:320-331. [PMID: 27371135 DOI: 10.1016/j.neuropharm.2016.06.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 06/22/2016] [Accepted: 06/23/2016] [Indexed: 10/21/2022]
Abstract
Stimulus-reward learning has been heavily linked to the reward-prediction error learning hypothesis and dopaminergic function. However, some evidence suggests dopaminergic function may not strictly underlie reward-prediction error learning, but may be specific to incentive salience attribution. Utilizing a Pavlovian conditioned approach procedure consisting of two stimuli that were equally reward-predictive (both undergoing reward-prediction error learning) but functionally distinct in regard to incentive salience (levers that elicited sign-tracking and tones that elicited goal-tracking), we tested the differential role of D1 and D2 dopamine receptors and nucleus accumbens dopamine in the acquisition of sign- and goal-tracking behavior and their associated conditioned reinforcing value within individuals. Overall, the results revealed that both D1 and D2 inhibition disrupted performance of sign- and goal-tracking. However, D1 inhibition specifically prevented the acquisition of sign-tracking to a lever, instead promoting goal-tracking and decreasing its conditioned reinforcing value, while neither D1 nor D2 signaling was required for goal-tracking in response to a tone. Likewise, nucleus accumbens dopaminergic lesions disrupted acquisition of sign-tracking to a lever, while leaving goal-tracking in response to a tone unaffected. Collectively, these results are the first evidence of an intraindividual dissociation of dopaminergic function in incentive salience attribution from reward-prediction error learning, indicating that incentive salience, reward-prediction error, and their associated dopaminergic signaling exist within individuals and are stimulus-specific. Thus, individual differences in incentive salience attribution may be reflective of a differential balance in dopaminergic function that may bias toward the attribution of incentive salience, relative to reward-prediction error learning only.
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Affiliation(s)
| | - Justin R Nickell
- Department of Pharmaceutical Sciences, University of Kentucky, USA
| | - Mahesh Darna
- Department of Pharmaceutical Sciences, University of Kentucky, USA
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Possin KL, Sanchez PE, Anderson-Bergman C, Fernandez R, Kerchner GA, Johnson ET, Davis A, Lo I, Bott NT, Kiely T, Fenesy MC, Miller BL, Kramer JH, Finkbeiner S. Cross-species translation of the Morris maze for Alzheimer's disease. J Clin Invest 2016; 126:779-83. [PMID: 26784542 DOI: 10.1172/jci78464] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 12/03/2015] [Indexed: 12/28/2022] Open
Abstract
Analogous behavioral assays are needed across animal models and human patients to improve translational research. Here, we examined the extent to which performance in the Morris water maze - the most frequently used behavioral assay of spatial learning and memory in rodents - translates to humans. We designed a virtual version of the assay for human subjects that includes the visible-target training, hidden-target learning, and probe trials that are typically administered in the mouse version. We compared transgenic mice that express human amyloid precursor protein (hAPP) and patients with mild cognitive impairment due to Alzheimer's disease (MCI-AD) to evaluate the sensitivity of performance measures in detecting deficits. Patients performed normally during visible-target training, while hAPP mice showed procedural learning deficits. In hidden-target learning and probe trials, hAPP mice and MCI-AD patients showed similar deficits in learning and remembering the target location. In addition, we have provided recommendations for selecting performance measures and sample sizes to make these assays sensitive to learning and memory deficits in humans with MCI-AD and in mouse models. Together, our results demonstrate that with careful study design and analysis, the Morris maze is a sensitive assay for detecting AD-relevant impairments across species.
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Bullmann T, Seeger G, Stieler J, Hanics J, Reimann K, Kretzschmann TP, Hilbrich I, Holzer M, Alpár A, Arendt T. Tau phosphorylation-associated spine regression does not impair hippocampal-dependent memory in hibernating golden hamsters. Hippocampus 2015; 26:301-18. [DOI: 10.1002/hipo.22522] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 08/12/2015] [Accepted: 08/31/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Torsten Bullmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
- Frey Initiative Research Unit, RIKEN Quantitative Biology Center; Japan
| | - Gudrun Seeger
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Jens Stieler
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - János Hanics
- MTA-SE NAP B Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences; Budapest Hungary
- Department of Anatomy; Semmelweis University; Budapest Hungary
| | - Katja Reimann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Tanja Petra Kretzschmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Isabel Hilbrich
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Max Holzer
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Alán Alpár
- MTA-SE NAP B Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences; Budapest Hungary
- Department of Anatomy; Semmelweis University; Budapest Hungary
| | - Thomas Arendt
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
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Hutsell BA, Banks ML. Effects of environmental and pharmacological manipulations on a novel delayed nonmatching-to-sample 'working memory' procedure in unrestrained rhesus monkeys. J Neurosci Methods 2015; 251:62-71. [PMID: 26003863 DOI: 10.1016/j.jneumeth.2015.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/11/2015] [Accepted: 05/13/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Working memory is a domain of 'executive function.' Delayed nonmatching-to-sample (DNMTS) procedures are commonly used to examine working memory in both human laboratory and preclinical studies. NEW METHOD The aim was to develop an automated DNMTS procedure maintained by food pellets in rhesus monkeys using a touch-sensitive screen attached to the housing chamber. Specifically, the DNMTS procedure was a 2-stimulus, 2-choice recognition memory task employing unidimensional discriminative stimuli and randomized delay interval presentations. RESULTS DNMTS maintained a delay-dependent decrease in discriminability that was independent of the retention interval distribution. Eliminating reinforcer availability during a single delay session or providing food pellets before the session did not systematically alter accuracy, but did reduce total choices. Increasing the intertrial interval enhanced accuracy at short delays. Acute Δ(9)-THC pretreatment produced delay interval-dependent changes in the forgetting function at doses that did not alter total choices. Acute methylphenidate pretreatment only decreased total choices. COMPARISON WITH EXISTING METHODS All monkeys were trained to perform NMTS at the 1s training delay within 60 days of initiating operant touch training. Furthermore, forgetting functions were reliably delay interval-dependent and stable over the experimental period (∼6 months). CONCLUSIONS Consistent with previous studies, increasing the intertrial interval improved DNMTS performance, whereas Δ(9)-THC disrupted DNMTS performance independent of changes in total choices. Overall, the touchscreen-based DNMTS procedure described provides an efficient method for training and testing experimental manipulations on working memory in unrestrained rhesus monkeys.
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Affiliation(s)
- Blake A Hutsell
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA
| | - Matthew L Banks
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA; Institute for Drug and Alcohol Abuse Studies, Virginia Commonwealth University, Richmond, VA, USA.
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Vaagenes IC, Tsai SY, Ton ST, Husak VA, McGuire SO, O’Brien TE, Kartje GL. Binge ethanol prior to traumatic brain injury worsens sensorimotor functional recovery in rats. PLoS One 2015; 10:e0120356. [PMID: 25768795 PMCID: PMC4359156 DOI: 10.1371/journal.pone.0120356] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 01/20/2015] [Indexed: 11/19/2022] Open
Abstract
A significant number of patients suffering from traumatic brain injury (TBI) have a high blood alcohol level at the time of injury. Furthermore, drinking alcohol in a binge-like pattern is now recognized as a national problem, leading to a greater likelihood of being injured. Our objective was to determine the consequences of a binge paradigm of alcohol intoxication at the time of TBI on long-term functional outcome using a sensitive test of sensorimotor function. We trained adult, male, Sprague Dawley rats on the skilled forelimb reaching task and then administered a single binge dose of ethanol (2g/kg, i.p.) or saline for three consecutive days (for a total of 3 doses). One hour after the final ethanol dose, rats underwent a TBI to the sensorimotor cortex corresponding to the preferred reaching forelimb. Animals were then tested for seven weeks on the skilled forelimb reaching task to assess the profile of recovery. We found that the group given ethanol prior to TBI displayed a slower recovery curve with a lower recovery plateau as compared to the control group. Therefore, even a relatively short (3 day) episode of binge alcohol exposure can negatively impact long-term recovery from a TBI, underscoring this significant public health problem.
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Affiliation(s)
- Ian C. Vaagenes
- Research Service, Edward Hines Jr. VA Hospital, Hines, Illinois, United States of America
- * E-mail:
| | - Shih-Yen Tsai
- Research Service, Edward Hines Jr. VA Hospital, Hines, Illinois, United States of America
| | - Son T. Ton
- Research Service, Edward Hines Jr. VA Hospital, Hines, Illinois, United States of America
- Neuroscience Research Institute, Loyola University Medical Center, Maywood, Illinois, United States of America
| | - Vicki A. Husak
- Research Service, Edward Hines Jr. VA Hospital, Hines, Illinois, United States of America
| | - Susan O. McGuire
- Research Service, Edward Hines Jr. VA Hospital, Hines, Illinois, United States of America
- Department of Anesthesiology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Timothy E. O’Brien
- Department of Mathematics and Statistics, Loyola University of Chicago, Chicago, Illinois, United States of America
| | - Gwendolyn L. Kartje
- Research Service, Edward Hines Jr. VA Hospital, Hines, Illinois, United States of America
- Department of Molecular Pharmacology and Therapeutics, Loyola University Medical Center, Maywood, Illinois, United States of America
- Neuroscience Research Institute, Loyola University Medical Center, Maywood, Illinois, United States of America
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Beckmann JS, Chow JJ. Isolating the incentive salience of reward-associated stimuli: value, choice, and persistence. ACTA ACUST UNITED AC 2015; 22:116-27. [PMID: 25593298 PMCID: PMC4341364 DOI: 10.1101/lm.037382.114] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Sign- and goal-tracking are differentially associated with drug abuse-related behavior. Recently, it has been hypothesized that sign- and goal-tracking behavior are mediated by different neurobehavioral valuation systems, including differential incentive salience attribution. Herein, we used different conditioned stimuli to preferentially elicit different response types to study the different incentive valuation characteristics of stimuli associated with sign- and goal-tracking within individuals. The results demonstrate that all stimuli used were equally effective conditioned stimuli; however, only a lever stimulus associated with sign-tracking behavior served as a robust conditioned reinforcer and was preferred over a tone associated with goal-tracking. Moreover, the incentive value attributed to the lever stimulus was capable of promoting suboptimal choice, leading to a significant reduction in reinforcers (food) earned. Furthermore, sign-tracking to a lever was more persistent than goal-tracking to a tone under omission and extinction contingencies. Finally, a conditional discrimination procedure demonstrated that sign-tracking to a lever and goal-tracking to a tone were dependent on learned stimulus–reinforcer relations. Collectively, these results suggest that the different neurobehavioral valuation processes proposed to govern sign- and goal-tracking behavior are independent but parallel processes within individuals. Examining these systems within individuals will provide a better understanding of how one system comes to dominate stimulus–reward learning, thus leading to the differential role these systems play in abuse-related behavior.
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Affiliation(s)
- Joshua S Beckmann
- Behavioral Neuroscience and Psychopharmacology, Department of Psychology, University of Kentucky, Lexington, Kentucky 40536-0509, USA
| | - Jonathan J Chow
- Behavioral Neuroscience and Psychopharmacology, Department of Psychology, University of Kentucky, Lexington, Kentucky 40536-0509, USA
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Semple BD, Trivedi A, Gimlin K, Noble-Haeusslein LJ. Neutrophil elastase mediates acute pathogenesis and is a determinant of long-term behavioral recovery after traumatic injury to the immature brain. Neurobiol Dis 2014; 74:263-80. [PMID: 25497734 DOI: 10.1016/j.nbd.2014.12.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 11/19/2014] [Accepted: 12/01/2014] [Indexed: 12/21/2022] Open
Abstract
While neutrophil elastase (NE), released by activated neutrophils, is a key mediator of secondary pathogenesis in adult models of brain ischemia and spinal cord injury, no studies to date have examined this protease in the context of the injured immature brain, where there is notable vulnerability resulting from inadequate antioxidant reserves and prolonged exposure to infiltrating neutrophils. We thus reasoned that NE may be a key determinant of secondary pathogenesis, and as such, adversely influence long-term neurological recovery. To address this hypothesis, wild-type (WT) and NE knockout (KO) mice were subjected to a controlled cortical impact at post-natal day 21, approximating a toddler-aged child. To determine if NE is required for neutrophil infiltration into the injured brain, and whether this protease contributes to vasogenic edema, we quantified neutrophil numbers and measured water content in the brains of each of these genotypes. While leukocyte trafficking was indistinguishable between genotypes, vasogenic edema was markedly attenuated in the NE KO. To determine if early pathogenesis is dependent on NE, indices of cell death (TUNEL and activated caspase-3) were quantified across genotypes. NE KO mice showed a reduction in these markers of cell death in the injured hippocampus, which corresponded to greater preservation of neuronal integrity as well as reduced expression of heme oxygenase-1, a marker of oxidative stress. WT mice, treated with a competitive inhibitor of NE at 2, 6 and 12h post-injury, likewise showed a reduction in cell death and oxidative stress compared to vehicle-treated controls. We next examined the long-term behavioral and structural consequences of NE deficiency. NE KO mice showed an improvement in long-term spatial memory retention and amelioration of injury-induced hyperactivity. However, volumetric and stereological analyses found comparable tissue loss in the injured cortex and hippocampus independent of genotype. Further, WT mice treated acutely with the NE inhibitor showed no long-term behavioral or structural improvements. Together, these findings validate the central role of NE in both acute pathogenesis and chronic functional recovery, and support future exploration of the therapeutic window, taking into account the prolonged period of neutrophil trafficking into the injured immature brain.
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Affiliation(s)
- Bridgette D Semple
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA; Department of Medicine (Royal Melbourne Hospital), University of Melbourne, Parkville, VIC 3000, Australia.
| | - Alpa Trivedi
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA.
| | - Kayleen Gimlin
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA.
| | - Linda J Noble-Haeusslein
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA; Department of Physical Therapy and Rehabilitation Sciences, University of California San Francisco, San Francisco, CA 94143, USA.
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Lazareva OF, Kandray K, Acerbo MJ. Hippocampal lesion and transitive inference: Dissociation of inference-based and reinforcement-based strategies in pigeons. Hippocampus 2014; 25:219-26. [DOI: 10.1002/hipo.22366] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2014] [Indexed: 11/10/2022]
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Bilateral lesions of nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS) selectively impair figure-ground discrimination in pigeons. Vis Neurosci 2013; 31:105-10. [PMID: 24103484 DOI: 10.1017/s0952523813000424] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Earlier, we reported that nucleus rotundus (Rt) together with its inhibitory complex, nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS), had significantly higher activity in pigeons performing figure-ground discrimination than in the control group that did not perform any visual discriminations. In contrast, color discrimination produced significantly higher activity than control in the Rt but not in the SP/IPS. Finally, shape discrimination produced significantly lower activity than control in both the Rt and the SP/IPS. In this study, we trained pigeons to simultaneously perform three visual discriminations (figure-ground, color, and shape) using the same stimulus displays. When birds learned to perform all three tasks concurrently at high levels of accuracy, we conducted bilateral chemical lesions of the SP/IPS. After a period of recovery, the birds were retrained on the same tasks to evaluate the effect of lesions on maintenance of these discriminations. We found that the lesions of the SP/IPS had no effect on color or shape discrimination and that they significantly impaired figure-ground discrimination. Together with our earlier data, these results suggest that the nucleus Rt and the SP/IPS are the key structures involved in figure-ground discrimination. These results also imply that thalamic processing is critical for figure-ground segregation in avian brain.
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Rich stimulus sampling for between-subjects designs improves model selection. Behav Res Methods 2011; 44:176-88. [DOI: 10.3758/s13428-011-0133-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Beckmann JS, Marusich JA, Gipson CD, Bardo MT. Novelty seeking, incentive salience and acquisition of cocaine self-administration in the rat. Behav Brain Res 2010; 216:159-65. [PMID: 20655954 DOI: 10.1016/j.bbr.2010.07.022] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 07/16/2010] [Accepted: 07/19/2010] [Indexed: 11/19/2022]
Abstract
It has been suggested that incentive salience plays a major role in drug abuse and the development of addiction. Additionally, novelty seeking has been identified as a significant risk factor for drug abuse. However, how differences in the readiness to attribute incentive salience relate to novelty seeking and drug abuse vulnerability has not been explored. The present experiments examined how individual differences in incentive salience attribution relate to novelty seeking and acquisition of cocaine self-administration in a preclinical model. Rats were first assessed in an inescapable novelty task and a novelty place preference task (measures of novelty seeking), followed by a Pavlovian conditioned approach task for food (a measure of incentive salience attribution). Rats then were trained to self-administer cocaine (0.3 or 1.0 mg/kg/infusion) using an autoshaping procedure. The results demonstrate that animals that attributed incentive salience to a food-associated cue were higher novelty seekers and acquired cocaine self-administration more quickly at the lower dose. The results suggest that novelty-seeking behavior may be a mediator of incentive salience attribution and that incentive salience magnitude may be an indicator of drug reward.
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Affiliation(s)
- Joshua S Beckmann
- University of Kentucky, Department of Psychology, 741 S. Limestone, BBSRB, Room 447, Lexington, KY 40536-0509, United States.
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