The effects of exercise on cocaine self-administration, food-maintained responding, and locomotor activity in female rats: Importance of the temporal relationship between physical activity and initial drug exposure.

AbstractUnderstanding factors contributing to individual differences in vulnerability to opioid addiction is essential for developing more effective preventions and treatments, yet few reliable behavioral predictors of subsequent opioid self-administration have been identified in rodents. Sensitivity to the acute effects of initial drug exposure predicts later addiction vulnerability in both humans and animals, but the relationship of sensitivity to withdrawal from initial drug exposure and later drug use vulnerability is unclear. The goal of the current study was to evaluate whether the degree of anhedonia experienced during withdrawal from early opioid exposure predicts subsequent vulnerability to opioid addiction. Rats were first tested for withdrawal sensitivity following acute injections of morphine (i.e., “acute dependence”), measured as elevations in intracranial self-stimulation (ICSS) thresholds (anhedonia-like behavior) during naloxone-precipitated and spontaneous withdrawal. Rats were then tested for addiction vulnerability using various measures of i.v. morphine self-administration (MSA) including acquisition, demand, extinction, and reinstatement induced by morphine, stress, and/or drug-associated cues. Greater naloxone-precipitated withdrawal across repeated morphine injections and greater peak spontaneous withdrawal severity following a single morphine injection were associated with lower addiction vulnerability on multiple MSA measures. Withdrawal-induced anhedonia predicted a wider range of MSA measures than did any individual measure of MSA itself. These data suggest that high anhedonia during withdrawal from initial opioid exposure is protective against subsequent opioid addiction vulnerability in rodents, thereby establishing one of the first behavioral measures to predict individual differences in opioid SA. This model promises to be useful for furthering our understanding of behavioral and neurobiological mechanisms underlying vulnerability to opioid addiction.

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Gestational IV Nicotine Potentiates Cocaine-Induced Locomotor Activity in Adult Female Rats

PsycEXTRA Dataset ◽

10.1037/e617962012-324 ◽

2008 ◽

Author(s):

Steven B. Harrod

Keyword(s):

Locomotor Activity ◽

Adult Female ◽

Female Rats

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Faculty Opinions recommendation of Locomotor activity in a novel environment predicts both responding for a visual stimulus and self-administration of a low dose of methamphetamine in rats.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.8388956.8840054 ◽

2011 ◽

Author(s):

Harriet de Wit

Keyword(s):

Locomotor Activity ◽

Visual Stimulus ◽

Low Dose ◽

Self Administration ◽

Novel Environment

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Enhanced heroin self-administration and distinct dopamine adaptations in female rats

Neuropsychopharmacology ◽

10.1038/s41386-021-01035-0 ◽

2021 ◽

Author(s):

Brianna E. George ◽

Samuel H. Barth ◽

Lindsey B. Kuiper ◽

Katherine M. Holleran ◽

Ryan T. Lacy ◽

...

Keyword(s):

Female Rats ◽

Self Administration

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Stamina-Enhancing Effects of Human Adipose-Derived Stem Cells

Cell Transplantation ◽

10.1177/09636897211035409 ◽

2021 ◽

Vol 30 ◽

pp. 096368972110354

Author(s):

Eun-Jung Yoon ◽

Hye Rim Seong ◽

Jangbeen Kyung ◽

Dajeong Kim ◽

Sangryong Park ◽

...

Keyword(s):

Physical Activity ◽

Stem Cells ◽

Locomotor Activity ◽

Tissue Injury ◽

Male Rats ◽

Adipose Derived Stem Cells ◽

Sprague Dawley ◽

Serum Triglycerides

Stamina-enhancing effects of human adipose derived stem cells (hADSCs) were investigated in young Sprague-Dawley rats. Ten-day-old male rats were transplanted intravenously (IV) or intracerebroventricularly (ICV) with hADSCs (1 × 106 cells/rat), and physical activity was measured by locomotor activity and rota-rod performance at post-natal day (PND) 14, 20, 30, and 40, as well as a forced swimming test at PND 41. hADSCs injection increased the moving time in locomotor activity, the latency in rota-rod performance, and the maximum swimming time. For the improvement of physical activity, ICV transplantation was superior to IV injection. In biochemical analyses, ICV transplantation of hADSCs markedly reduced serum creatine phosphokinase, lactate dehydrogenase, alanine transaminase, and muscular lipid peroxidation, the markers for muscular and hepatic injuries, despite the reduction in muscular glycogen and serum triglycerides as energy sources. Notably, hADSCs secreted brain-derived neurotrophic factor (BDNF) and nerve growth factor in vitro, and increased the level of BDNF in the brain and muscles in vivo. The results indicate that hADSCs enhance physical activity including stamina not only by attenuating tissue injury, but also by strengthening the muscles via production of BDNF.

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Sex Differences in the Reward-Enhancing Effects of Nicotine on Ethanol Reinforcement: A Reinforcer Demand Analysis

Nicotine & Tobacco Research ◽

10.1093/ntr/ntz056 ◽

2019 ◽

Vol 22 (2) ◽

pp. 238-247 ◽

Cited By ~ 1

Author(s):

Scott T Barrett ◽

Brady M Thompson ◽

Jessica R Emory ◽

Chris E Larsen ◽

Steven T Pittenger ◽

...

Keyword(s):

Alcohol Abuse ◽

Ethanol Solution ◽

Female Rats ◽

Demand Model ◽

Self Administration ◽

Biological Sex ◽

Ethanol Reinforcement ◽

Nicotine Abuse ◽

Reinforcer Demand ◽

Reinforcement Value

Abstract Background Alcohol is often consumed with tobacco, and dependence to alcohol and tobacco are highly comorbid. In addition, there are differences in the prevalence of nicotine- and alcohol-abuse between the sexes. Nicotine produces enhancing effects on the value of other reinforcers, which may extend to alcohol. Methods Male and female Wistar rats were trained to self-administer 15% ethanol solution in 30-minute sessions. Once ethanol self-administration was established, demand for ethanol was evaluated using an exponential reinforcer demand method, in which the response cost per reinforcer delivery was systematically increased over blocks of several sessions. Within each cost condition, rats were preinjected with nicotine (0.05, 0.1, 0.2, or 0.4 mg/kg base, SC) or saline 5 minutes before self-administration sessions. The effects of nicotine dose and biological sex were evaluated using the estimates generated by the reinforcer demand model. Results Under saline conditions, males showed greater sensitivity to ethanol reinforcement than females. Nicotine enhanced the reinforcement value of alcohol and this varied with sex. In both sexes, 0.4 mg/kg nicotine decreased intensity of ethanol demand. However, 0.05, 0.1, and 0.2 mg/kg nicotine decreased elasticity of ethanol demand in females, but not in males. Conclusions Nicotine enhances ethanol reinforcement, which may partially drive comorbidity between nicotine-abuse and alcohol-abuse. Males showed signs of greater ethanol reinforcement value than females under saline conditions, and nicotine attenuated this effect by increasing ethanol reinforcement value in the females. These findings highlight that a complete understanding of alcohol-abuse must include a thorough study of alcohol use in the context of other drug use, including nicotine. Implications Nicotine dose dependently enhances the alcohol reinforcement value in a manner that is clearly influenced by biological sex. Under saline baseline conditions, males show lower elasticity of demand for alcohol reinforcement than females, indicative of greater reinforcement value. However, nicotine attenuated this difference by enhancing alcohol reward in the females. Specifically, low-to-moderate doses (0.05–0.2 mg/kg) of nicotine decreased elasticity of alcohol demand in female rats, increasing the perseverance of their alcohol taking behavior. These data indicate that the well-documented reward-enhancing effects of nicotine on sensory reinforcement extend to alcohol reinforcement and that these vary with biological sex.

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Sex Differences in Escalated Methamphetamine Self-Administration and Altered Gene Expression Associated With Incubation of Methamphetamine Seeking

The International Journal of Neuropsychopharmacology ◽

10.1093/ijnp/pyz050 ◽

2019 ◽

Vol 22 (11) ◽

pp. 710-723 ◽

Cited By ~ 8

Author(s):

Atul P Daiwile ◽

Subramaniam Jayanthi ◽

Bruce Ladenheim ◽

Michael T McCoy ◽

Christie Brannock ◽

...

Keyword(s):

Sex Differences ◽

Nucleus Accumbens ◽

Fixed Ratio ◽

Female Rats ◽

Male Rats ◽

Mrna Levels ◽

Self Administration ◽

Male And Female ◽

Orexin Receptors ◽

Male And Female Rats

Abstract Background Methamphetamine (METH) use disorder is prevalent worldwide. There are reports of sex differences in quantities of drug used and relapses to drug use among individuals with METH use disorder. However, the molecular neurobiology of these potential sex differences remains unknown. Methods We trained rats to self-administer METH (0. 1 mg/kg/infusion, i.v.) on an fixed-ratio-1 schedule for 20 days using two 3-hour daily METH sessions separated by 30-minute breaks. At the end of self-administration training, rats underwent tests of cue-induced METH seeking on withdrawal days 3 and 30. Twenty-four hours later, nucleus accumbens was dissected and then used to measure neuropeptide mRNA levels. Results Behavioral results show that male rats increased the number of METH infusions earlier during self-administration training and took more METH than females. Both male and female rats could be further divided into 2 phenotypes labeled high and low takers based on the degree of escalation that they exhibited during the course of the METH self-administration experiment. Both males and females exhibited incubation of METH seeking after 30 days of forced withdrawal. Females had higher basal mRNA levels of dynorphin and hypocretin/orexin receptors than males, whereas males expressed higher vasopressin mRNA levels than females under saline and METH conditions. Unexpectedly, only males showed increased expression of nucleus accumbens dynorphin after METH self-administration. Moreover, there were significant correlations between nucleus accumbens Hcrtr1, Hcrtr2, Crhr2, and Avpr1b mRNA levels and cue-induced METH seeking only in female rats. Conclusion Our results identify some behavioral and molecular differences between male and female rats that had self-administered METH. Sexual dimorphism in responses to METH exposure should be considered when developing potential therapeutic agents against METH use disorder.

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Nicotine's effects on female rats' body weight: Caloric intake and physical activity

Pharmacology Biochemistry and Behavior ◽

10.1016/0091-3057(86)90099-7 ◽

1986 ◽

Vol 25 (6) ◽

pp. 1131-1136 ◽

Cited By ~ 32

Author(s):

Deborah J. Bowen ◽

Sharon E. Eury ◽

Neil E. Grunberg

Keyword(s):

Physical Activity ◽

Body Weight ◽

Caloric Intake ◽

Female Rats

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Female rats selectively bred for high intrinsic aerobic fitness are protected from ovariectomy-associated metabolic dysfunction

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00401.2014 ◽

2015 ◽

Vol 308 (6) ◽

pp. R530-R542 ◽

Cited By ~ 34

Author(s):

Victoria J. Vieira-Potter ◽

Jaume Padilla ◽

Young-Min Park ◽

Rebecca J. Welly ◽

Rebecca J. Scroggins ◽

...

Keyword(s):

Physical Activity ◽

Insulin Resistance ◽

Skeletal Muscle ◽

Energy Expenditure ◽

Aerobic Fitness ◽

Resting Energy Expenditure ◽

Female Rats ◽

Metabolic Dysfunction ◽

Spontaneous Physical Activity ◽

Resting Energy

Ovariectomized rodents model human menopause in that they rapidly gain weight, reduce spontaneous physical activity (SPA), and develop metabolic dysfunction, including insulin resistance. How contrasting aerobic fitness levels impacts ovariectomy (OVX)-associated metabolic dysfunction is not known. Female rats selectively bred for high and low intrinsic aerobic fitness [high-capacity runners (HCR) and low-capacity runners (LCR), respectively] were maintained under sedentary conditions for 39 wk. Midway through the observation period, OVX or sham (SHM) operations were performed providing HCR-SHM, HCR-OVX, LCR-SHM, and LCR-OVX groups. Glucose tolerance, energy expenditure, and SPA were measured before and 4 wk after surgery, while body composition via dual-energy X-ray absorptiometry and adipose tissue distribution, brown adipose tissue (BAT), and skeletal muscle phenotype, hepatic lipid content, insulin resistance via homeostatic assessment model of insulin resistance and AdipoIR, and blood lipids were assessed at death. Remarkably, HCR were protected from OVX-associated increases in adiposity and insulin resistance, observed only in LCR. HCR rats were ∼30% smaller, had ∼70% greater spontaneous physical activity (SPA), consumed ∼10% more relative energy, had greater skeletal muscle proliferator-activated receptor coactivator 1-alpha, and ∼40% more BAT. OVX did not increase energy intake and reduced SPA to the same extent in both HCR and LCR. LCR were particularly affected by an OVX-associated reduction in resting energy expenditure and experienced a reduction in relative BAT; resting energy expenditure correlated positively with BAT across all animals ( r = 0.6; P < 0.001). In conclusion, despite reduced SPA following OVX, high intrinsic aerobic fitness protects against OVX-associated increases in adiposity and insulin resistance. The mechanism may involve preservation of resting energy expenditure.

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