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Jean A, Mhaouty-Kodja S, Hardin-Pouzet H. Hypothalamic cellular and molecular plasticity linked to sexual experience in male rats and mice. Front Neuroendocrinol 2021; 63:100949. [PMID: 34687674 DOI: 10.1016/j.yfrne.2021.100949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/22/2021] [Accepted: 10/18/2021] [Indexed: 10/20/2022]
Abstract
Male sexual behavior is subject to learning, resulting in increased efficiency of experienced males compared to naive ones. The improvement in behavioral parameters is underpinned by cellular and molecular changes in the neural circuit controlling sexual behavior, particularly in the hypothalamic medial preoptic area. This review provides an update on the mechanisms related to the sexual experience in male rodents, emphasizing the differences between rats and mice.
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Affiliation(s)
- Arnaud Jean
- Sorbonne Université - Faculté de Sciences et Ingénierie, Neuroplasticité des Comportements de la Reproduction, Neurosciences Paris Seine, UM119 - CNRS UMR 8246 - INSERM UMRS 1130, 7 quai Saint Bernard, 75 005 Paris, France
| | - Sakina Mhaouty-Kodja
- Sorbonne Université - Faculté de Sciences et Ingénierie, Neuroplasticité des Comportements de la Reproduction, Neurosciences Paris Seine, UM119 - CNRS UMR 8246 - INSERM UMRS 1130, 7 quai Saint Bernard, 75 005 Paris, France
| | - Hélène Hardin-Pouzet
- Sorbonne Université - Faculté de Sciences et Ingénierie, Neuroplasticité des Comportements de la Reproduction, Neurosciences Paris Seine, UM119 - CNRS UMR 8246 - INSERM UMRS 1130, 7 quai Saint Bernard, 75 005 Paris, France.
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2
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Marler CA, Trainor BC. The challenge hypothesis revisited: Focus on reproductive experience and neural mechanisms. Horm Behav 2020; 123:104645. [PMID: 31778720 DOI: 10.1016/j.yhbeh.2019.104645] [Citation(s) in RCA: 8] [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: 08/28/2019] [Revised: 10/20/2019] [Accepted: 10/28/2019] [Indexed: 12/21/2022]
Abstract
Our review focuses on findings from mammals as part of a Special Issue "30th Anniversary of the Challenge Hypothesis". Here we put forth an integration of the mechanisms through which testosterone controls territorial behavior and consider how reproductive experience may alter these mechanisms. The emphasis is placed on the function of socially induced increases in testosterone (T) pulses, which occur in response to social interactions, as elegantly developed by Wingfield and colleagues. We focus on findings from the monogamous California mouse, as data from this species shows that reproductive status is a key factor influencing social interactions, site fidelity, and vigilance for offspring defense. Specifically, we examine differences in T pulses in sexually naïve versus sexually experienced pair bonded males. Testosterone pulses influence processes such as social decision making, the winner-challenge effect, and location preferences through rewarding effects of T. We also consider how social and predatory vigilance contribute to T pulses and how these interactions contribute to a territory centered around maximizing reproduction. Possible underlying mechanisms for these effects include the nucleus accumbens (rewarding effects of testosterone), hippocampus (spatial memories for territories), and the bed nucleus of the stria terminalis (social vigilance). The development of the challenge effect has provided an ideal framework for understanding the complex network of behavioral, environmental, physiological and neural mechanisms that ultimately relates to competition and territoriality across taxa. The opportunity to merge research on the challenge effect using both laboratory and field research to understand social behavior is unparalleled.
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Affiliation(s)
- Catherine A Marler
- Department of Psychology, University of Wisconsin, Madison, WI 53706, USA.
| | - Brian C Trainor
- Department of Psychology, University of California, Davis, CA 95616, USA
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3
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Knight EL, Sarkar A, Prasad S, Mehta PH. Beyond the challenge hypothesis: The emergence of the dual-hormone hypothesis and recommendations for future research. Horm Behav 2020; 123:104657. [PMID: 31863735 PMCID: PMC7311256 DOI: 10.1016/j.yhbeh.2019.104657] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/12/2019] [Accepted: 12/16/2019] [Indexed: 11/20/2022]
Abstract
The challenge hypothesis makes specific predictions about the association between testosterone and status-seeking behaviors, but the findings linking testosterone to these behaviors are often inconsistent. The dual-hormone hypothesis was developed to help explain these inconsistencies. Specifically, according to this hypothesis, testosterone's association with status-seeking behavior depends on levels of cortisol. Here, we (1) describe the dual-hormone hypothesis in relation to the challenge hypothesis; (2) review recent studies that tested the dual-hormone hypothesis as well as meta-scientific evidence of heterogeneous dual-hormone findings across studies; (3) discuss potential explanations for this heterogeneity, including methodological considerations, contextual factors, and individual differences; and (4) provide recommendations for new work aimed at testing and extending the dual-hormone hypothesis.
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Affiliation(s)
- Erik L Knight
- Center for Healthy Aging, Pennsylvania State University, United States of America; Department of Biobehavioral Health, Pennsylvania State University, United States of America.
| | - Amar Sarkar
- Trinity College, University of Cambridge, United Kingdom; Leverhulme Centre for Human Evolutionary Studies, Department of Archaeology, University of Cambridge, United Kingdom
| | - Smrithi Prasad
- Marshall School of Business, University of Southern California, United States of America
| | - Pranjal H Mehta
- Department of Experimental Psychology, University College London, United Kingdom
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4
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Timonin ME, Kalcounis‐Rueppell MC, Marler CA. Testosterone pulses at the nest site modify ultrasonic vocalization types in a monogamous and territorial mouse. Ethology 2018. [DOI: 10.1111/eth.12812] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Mary E. Timonin
- Department of Biology University of North Carolina at Greensboro Greensboro North Carolina
| | | | - Catherine A. Marler
- Department of Psychology University of Wisconsin, Madison Madison Wisconsin
- Department of Biology University of Wisconsin, Madison Madison Wisconsin
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5
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Fuxjager MJ, Trainor BC, Marler CA. What can animal research tell us about the link between androgens and social competition in humans? Horm Behav 2017; 92:182-189. [PMID: 27914879 DOI: 10.1016/j.yhbeh.2016.11.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 11/14/2016] [Accepted: 11/15/2016] [Indexed: 10/20/2022]
Abstract
A contribution to a special issue on Hormones and Human Competition. The relationship between androgenic hormones, like testosterone (T), and aggression is extensively studied in human populations. Yet, while this work has illuminated a variety of principals regarding the behavioral and phenotypic effects of T, it is also hindered by inherent limitations of performing research on people. In these instances, animal research can be used to gain further insight into the complex mechanisms by which T influences aggression. Here, we explore recent studies on T and aggression in numerous vertebrate species, although we focus primarily on males and on a New World rodent called the California mouse (Peromyscus californicus). This species is highly territorial and monogamous, resembling the modern human social disposition. We review (i) how baseline and dynamic T levels predict and/or impact aggressive behavior and disposition; (ii) how factors related to social and physical context influence T and aggression; (iii) the reinforcing or "rewarding" aspects of aggressive behavior; and (iv) the function of T on aggression before and during a combative encounter. Included are areas that may need further research. We argue that animal studies investigating these topics fill in gaps to help paint a more complete picture of how androgenic steroids drive the output of aggressive behavior in all animals, including humans.
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Affiliation(s)
| | - Brian C Trainor
- Neuroscience Graduate Group, University of California, Davis, CA, USA; Department of Psychology, University of California, Davis, CA 95616, USA; Center for Neuroscience, University of California, Davis, CA 95616, USA
| | - Catherine A Marler
- Department of Psychology, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Zoology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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6
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Ng Tang Fui M, Hoermann R, Grossmann M. Effect of Testosterone Treatment on Adipokines and Gut Hormones in Obese Men on a Hypocaloric Diet. J Endocr Soc 2017; 1:302-312. [PMID: 29264488 PMCID: PMC5686636 DOI: 10.1210/js.2017-00062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 02/23/2017] [Indexed: 11/19/2022] Open
Abstract
Context In obese men with lowered testosterone levels, testosterone treatment augments diet-associated loss of body fat. Objective We hypothesized that testosterone treatment modulates circulating concentrations of hormonal mediators of fat mass and energy homeostasis in obese men undergoing a weight loss program. Design Prespecified secondary analysis of a randomized, double-blind, placebo-controlled trial. Setting Tertiary referral center. Participants Obese men (body mass index ≥30 kg/m2) with a repeated total testosterone level ≤12 nmol/L. Intervention One hundred participants mean age 53 years (interquartile range 47 to 60 years) receiving 10 weeks of a very low-energy diet followed by 46 weeks of weight maintenance were randomly assigned at baseline to 56 weeks of intramuscular testosterone undecanoate (cases, n = 49) or matching placebo (controls, n = 51). Eighty-two men completed the study. Main outcomes Between-group differences in leptin, adiponectin, ghrelin, glucagon like peptide-1, gastric inhibitory polypeptide, peptide YY, pancreatic polypeptide, and amylin levels. Results At study end, compared with controls, cases had greater reductions in leptin [mean adjusted difference (MAD), -3.6 ng/mL (95% CI, -5.3 to -1.9); P < 0.001]. The change in leptin levels between cases and controls was dependent on baseline fat mass, as the between-group difference progressively increased with increasing fat mass [MAD, -0.26 ng/mL (95% CI, -0.31 to -0.26); P = 0.001 per 1 kg of baseline fat mass]. Weight loss-associated changes in other hormones persisted during the weight maintenance phase but were not modified by testosterone treatment. Conclusions Testosterone treatment led to reductions in leptin beyond those achieved by diet-associated weight loss. Testosterone treatment may reduce leptin resistance in obese men.
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Affiliation(s)
- Mark Ng Tang Fui
- Department of Medicine, and.,Department of Endocrinology, Austin Health, University of Melbourne, Heidelberg, Victoria, 3084 Australia
| | | | - Mathis Grossmann
- Department of Medicine, and.,Department of Endocrinology, Austin Health, University of Melbourne, Heidelberg, Victoria, 3084 Australia
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Grönbladh A, Nylander E, Hallberg M. The neurobiology and addiction potential of anabolic androgenic steroids and the effects of growth hormone. Brain Res Bull 2016; 126:127-137. [DOI: 10.1016/j.brainresbull.2016.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 12/30/2022]
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8
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Deviche P, Bittner S, Davies S, Valle S, Gao S, Carpentier E. Endocrine, metabolic, and behavioral effects of and recovery from acute stress in a free-ranging bird. Gen Comp Endocrinol 2016; 234:95-102. [PMID: 27311790 DOI: 10.1016/j.ygcen.2016.06.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 06/09/2016] [Accepted: 06/11/2016] [Indexed: 11/18/2022]
Abstract
Acute stress in vertebrates generally stimulates the hypothalamo-pituitary-adrenal axis and is often associated with multiple metabolic changes, such as increased gluconeogenesis, and with behavioral alterations. Little information is available, especially in free-ranging organisms, on the duration of these reversible effects once animals are no longer exposed to the stressor. To investigate this question, we exposed free-ranging adult male Rufous-winged Sparrows, Peucaea carpalis, in breeding condition to a standard protocol consisting of a social challenge (conspecific song playback) followed with capture and restraint for 30min, after which birds were released on site. Capture and restraint increased plasma corticosterone (CORT) and decreased plasma testosterone (T), glucose (GLU), and uric acid (UA). In birds that we recaptured the next day after exposure to conspecific song playback, plasma CORT and UA levels no longer differed from levels immediately after capture the preceding day. However, plasma T was similar to that measured after stress exposure the preceding day, and plasma GLU was markedly elevated. Thus, exposure to social challenge and acute stress resulted in persistent (⩾24h) parameter-specific effects. In recaptured sparrows, the territorial aggressive response to conspecific song playback, as measured by song rate and the number of flights over the song-broadcasting speakers, did not, however, differ between the first capture and the recapture, suggesting no proximate functional association between plasma T and conspecific territorial aggression. The study is the first in free-ranging birds to report the endocrine, metabolic, and behavioral recovery from the effects of combined social challenge and acute stress.
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Affiliation(s)
- Pierre Deviche
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA.
| | - Stephanie Bittner
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Scott Davies
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Shelley Valle
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Sisi Gao
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Elodie Carpentier
- Universite de Poitiers, Faculte des Sciences Fondamentales et Appliquees, Poitiers F-86022, France
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Crewther BT, Carruthers J, Kilduff LP, Sanctuary CE, Cook CJ. Temporal associations between individual changes in hormones, training motivation and physical performance in elite and non-elite trained men. Biol Sport 2016; 33:215-21. [PMID: 27601775 PMCID: PMC4993136 DOI: 10.5604/20831862.1201810] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/23/2015] [Accepted: 01/09/2016] [Indexed: 01/11/2023] Open
Abstract
To advance our understanding of the hormonal contribution to athletic performance, we examined the temporal associations between individual changes in testosterone (T) and/or cortisol (C) concentrations, training motivation and physical performance in elite and non-elite trained men. Two male cohorts classified as elites (n = 12) and non-elites (n = 12) completed five testing sessions over a six-week period. The athletes were tested for salivary T, C, T/C ratio, self-perceived training motivation, countermovement jump (CMJ) height and isometric mid-thigh pull peak force (IMTP PF), after which an actual training workout was performed. The elite men reported higher motivation to train and they produced greater CMJ height overall, whereas the non-elites had higher pooled T levels (p < 0.05). No significant group differences in C concentrations, T/C ratio or IMTP PF were found. The individual changes in T levels were positively associated with training motivation in the elite men only (p = 0.033), but the hormonal and motivation measures did not predict CMJ height or IMTP PF in either group. The monitoring of elite and non-elite men across a short training block revealed differences in T levels, motivation and lower-body power, which may reflect training and competitive factors in each group. Despite having lower T levels, the elite athletes showed better linkage between pre-training T fluctuations and subsequent motivation to train. The nature of the performance tests (i.e. single repetition trials) could partly explain the lack of an association with the hormonal and motivational measures.
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Affiliation(s)
- B T Crewther
- Institute of Sport - National Research Institute, Warsaw, Poland; Hamlyn Centre, Imperial College, London, UK
| | - J Carruthers
- Al-Attar Physical Medicine, Rehabilitation and Sports Medicine Center, Doha, Qatar
| | - L P Kilduff
- Applied Sports, Technology, Exercise and Medicine, College of Engineering, Swansea University, Swansea, UK; Welsh Institute of Performance Science, Swansea University, Swansea, UK
| | - C E Sanctuary
- Newcastle Knights Rugby League, Newcastle, Australia
| | - C J Cook
- Hamlyn Centre, Imperial College, London, UK; School of Sport, Health and Exercise Science, Bangor University, Bangor, UK; Welsh Institute of Performance Science, Swansea University, Swansea, UK
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10
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Engi SA, Planeta CS, Crestani CC. Effect of Voluntary Ethanol Consumption Combined with Testosterone Treatment on Cardiovascular Function in Rats: Influence of Exercise Training. PLoS One 2016; 11:e0146974. [PMID: 26760038 PMCID: PMC4711937 DOI: 10.1371/journal.pone.0146974] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/23/2015] [Indexed: 01/15/2023] Open
Abstract
This study evaluated the effects of voluntary ethanol consumption combined with testosterone treatment on cardiovascular function in rats. Moreover, we investigated the influence of exercise training on these effects. To this end, male rats were submitted to low-intensity training on a treadmill or kept sedentary while concurrently being treated with ethanol for 6 weeks. For voluntary ethanol intake, rats were given access to two bottles, one containing ethanol and other containing water, three 24-hour sessions per week. In the last two weeks (weeks 5 and 6), animals underwent testosterone treatment concurrently with exercise training and exposure to ethanol. Ethanol consumption was not affected by either testosterone treatment or exercise training. Also, drug treatments did not influence the treadmill performance improvement evoked by training. However, testosterone alone, but not in combination with ethanol, reduced resting heart rate. Moreover, combined treatment with testosterone and ethanol reduced the pressor response to the selective α1-adrenoceptor agonist phenylephrine. Treatment with either testosterone or ethanol alone also affected baroreflex activity and enhanced depressor response to acetylcholine, but these effects were inhibited when drugs were coadministrated. Exercise training restored most cardiovascular effects evoked by drug treatments. Furthermore, both drugs administrated alone increased pressor response to phenylephrine in trained animals. Also, drug treatments inhibited the beneficial effects of training on baroreflex function. In conclusion, the present results suggest a potential interaction between toxic effects of testosterone and ethanol on cardiovascular function. Data also indicate that exercise training is an important factor influencing the effects of these substances.
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Affiliation(s)
- Sheila A. Engi
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista-UNESP, Araraquara, SP, Brazil
- Joint UFSCar-UNESP Graduate Program in Physiological Sciences, São Carlos, SP, Brazil
| | - Cleopatra S. Planeta
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista-UNESP, Araraquara, SP, Brazil
- Joint UFSCar-UNESP Graduate Program in Physiological Sciences, São Carlos, SP, Brazil
| | - Carlos C. Crestani
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista-UNESP, Araraquara, SP, Brazil
- Joint UFSCar-UNESP Graduate Program in Physiological Sciences, São Carlos, SP, Brazil
- * E-mail:
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11
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Gauvin DV, Zimmermann ZJ, Baird TJ. Preclinical assessment of abuse liability of biologics: In defense of current regulatory control policies. Regul Toxicol Pharmacol 2015; 73:43-54. [DOI: 10.1016/j.yrtph.2015.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 01/16/2023]
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12
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Mhillaj E, Morgese MG, Tucci P, Bove M, Schiavone S, Trabace L. Effects of anabolic-androgens on brain reward function. Front Neurosci 2015; 9:295. [PMID: 26379484 PMCID: PMC4549565 DOI: 10.3389/fnins.2015.00295] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 08/06/2015] [Indexed: 12/02/2022] Open
Abstract
Androgens are mainly prescribed to treat several diseases caused by testosterone deficiency. However, athletes try to promote muscle growth by manipulating testosterone levels or assuming androgen anabolic steroids (AAS). These substances were originally synthesized to obtain anabolic effects greater than testosterone. Although AAS are rarely prescribed compared to testosterone, their off-label utilization is very wide. Furthermore, combinations of different steroids and doses generally higher than those used in therapy are common. Symptoms of the chronic use of supra-therapeutic doses of AAS include anxiety, depression, aggression, paranoia, distractibility, confusion, amnesia. Interestingly, some studies have shown that AAS elicited electroencephalographic changes similar to those observed with amphetamine abuse. The frequency of side effects is higher among AAS abusers, with psychiatric complications such as labile mood, lack of impulse control and high violence. On the other hand, AAS addiction studies are complex because data collection is very difficult due to the subjects' reticence and can be biased by many variables, including physical exercise, that alter the reward system. Moreover, it has been reported that AAS may imbalance neurotransmitter systems involved in the reward process, leading to increased sensitivity toward opioid narcotics and central stimulants. The goal of this article is to review the literature on steroid abuse and changes to the reward system in preclinical and clinical studies.
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Affiliation(s)
- Emanuela Mhillaj
- Department of Physiology and Pharmacology, Sapienza University of Rome Rome, Italy
| | - Maria G Morgese
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
| | - Paolo Tucci
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
| | - Maria Bove
- Department of Physiology and Pharmacology, Sapienza University of Rome Rome, Italy
| | - Stefania Schiavone
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
| | - Luigia Trabace
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
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Anabolic-androgenic steroids and decision making: Probability and effort discounting in male rats. Psychoneuroendocrinology 2015; 57:84-92. [PMID: 25900595 PMCID: PMC4437834 DOI: 10.1016/j.psyneuen.2015.03.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 03/09/2015] [Accepted: 03/30/2015] [Indexed: 12/11/2022]
Abstract
Anabolic-androgenic steroid (AAS) abuse is implicated in maladaptive behaviors such as increased aggression and risk taking. Impaired judgment due to changes in the mesocorticolimbic dopamine system may contribute to these behavioral changes. While AAS are known to influence dopamine function in mesocorticolimbic circuitry, the effects on decision making are unknown. This was the focus of the present study. Adolescent male Long-Evans rats were treated chronically with high-dose testosterone (7.5 mg/kg) or vehicle (13% cyclodextrin in water), and tested for cost/benefit decision making in two discounting paradigms. Rats chose between a small reward (1 sugar pellet) and a large discounted reward (3 or 4 pellets). Probability discounting (PD) measures sensitivity to reward uncertainty by decreasing the probability (100, 75, 50, 25, 0%) of receiving the large reward in successive blocks of each daily session. Effort discounting (ED) measures sensitivity to a work cost by increasing the lever presses required to earn the large reward (1, 2, 5, 10, 15 presses). In PD, testosterone-treated rats selected the large/uncertain reward significantly less than vehicle-treated controls. However, during ED, testosterone-treated rats selected the large/high effort reward significantly more than controls. These studies show that testosterone has divergent effects on different aspects of decision making. Specifically, testosterone increases aversion to uncertainty but decreases sensitivity to the output of effort for reward. These results have implications for understanding maladaptive behavioral changes in human AAS users.
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14
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Abstract
Testosterone is a key hormone in the pathology of metabolic diseases such as obesity. Low testosterone levels are associated with increased fat mass (particularly central adiposity) and reduced lean mass in males. These morphological features are linked to metabolic dysfunction, and testosterone deficiency is associated with energy imbalance, impaired glucose control, reduced insulin sensitivity and dyslipidaemia. A bidirectional relationship between testosterone and obesity underpins this association indicated by the hypogonadal-obesity cycle and evidence weight loss can lead to increased testosterone levels. Androgenic effects on enzymatic pathways of fatty acid metabolism, glucose control and energy utilization are apparent and often tissue specific with differential effects noted in different regional fat depots, muscle and liver to potentially explain the mechanisms of testosterone action. Testosterone replacement therapy demonstrates beneficial effects on measures of obesity that are partially explained by both direct metabolic actions on adipose and muscle and also potentially by increasing motivation, vigour and energy allowing obese individuals to engage in more active lifestyles. The degree of these beneficial effects may be dependent on the treatment modality with longer term administration often achieving greater improvements. Testosterone replacement may therefore potentially be an effective adjunctive treatment for weight management in obese men with concomitant hypogonadism.
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Affiliation(s)
- D M Kelly
- Department of Human Metabolism, Medical School, The University of Sheffield, Sheffield, UK
| | - T H Jones
- Department of Human Metabolism, Medical School, The University of Sheffield, Sheffield, UK.,Centre for Diabetes and Endocrinology, Barnsley Hospital NHS Foundation Trust, Barnsley, UK
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15
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Zhao X, Marler CA. Pair bonding prevents reinforcing effects of testosterone in male California mice in an unfamiliar environment. Proc Biol Sci 2015; 281:20140985. [PMID: 24943373 DOI: 10.1098/rspb.2014.0985] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Testosterone (T) can be released by stimuli such as social interactions, and thereby influence future social behaviours. Because the reinforcing effects of T can induce preferences for specific environmental locations, T has the potential to alter behaviour through space use. In a monogamous species, this T pulse may contribute differently to space use in sexually naive (SN) and pair-bonded (PB) males: SN males may be more likely to explore new areas to set up a territory than PB males, which are more likely to defend an existing, established territory. In this study, we test for variation in T-driven space use by examining variation in the formation of conditioned place preferences (CPPs) in SN and PB male California mice. In the three-chambered CPP apparatus, subcutaneous administrations of physiological levels of T were used to repeatedly condition SN and PB males to a side chamber, which is an unfamiliar/neutral environment. The final tests revealed that T-induced CPPs in the side chamber are developed in SN, but not PB males. This study fills a gap in our knowledge about plasticity in the rewarding nature of T pulses, based on past social experience.
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Affiliation(s)
- Xin Zhao
- Department of Psychology, University of Wisconsin, Madison, WI 53706, USA
| | - Catherine A Marler
- Department of Psychology, University of Wisconsin, Madison, WI 53706, USA
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16
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Fui MNT, Dupuis P, Grossmann M. Lowered testosterone in male obesity: mechanisms, morbidity and management. Asian J Androl 2014; 16:223-31. [PMID: 24407187 PMCID: PMC3955331 DOI: 10.4103/1008-682x.122365] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
With increasing modernization and urbanization of Asia, much of the future focus of the obesity epidemic will be in the Asian region. Low testosterone levels are frequently encountered in obese men who do not otherwise have a recognizable hypothalamic-pituitary-testicular (HPT) axis pathology. Moderate obesity predominantly decreases total testosterone due to insulin resistance-associated reductions in sex hormone binding globulin. More severe obesity is additionally associated with reductions in free testosterone levels due to suppression of the HPT axis. Low testosterone by itself leads to increasing adiposity, creating a self-perpetuating cycle of metabolic complications. Obesity-associated hypotestosteronemia is a functional, non-permanent state, which can be reversible, but this requires substantial weight loss. While testosterone treatment can lead to moderate reductions in fat mass, obesity by itself, in the absence of symptomatic androgen deficiency, is not an established indication for testosterone therapy. Testosterone therapy may lead to a worsening of untreated sleep apnea and compromise fertility. Whether testosterone therapy augments diet- and exercise-induced weight loss requires evaluation in adequately designed randomized controlled clinical trials.
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Affiliation(s)
| | | | - Mathis Grossmann
- Department of Medicine Austin Health, University of Melbourne, Melbourne; Department of Endocrinology, Austin Health, Melbourne, Victoria, Australia
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Kim JY, Wood RI. Anabolic-androgenic steroids and appetitive sexual behavior in male rats. Horm Behav 2014; 66:585-90. [PMID: 25200201 PMCID: PMC4253570 DOI: 10.1016/j.yhbeh.2014.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 08/26/2014] [Accepted: 08/29/2014] [Indexed: 11/25/2022]
Abstract
Anabolic-androgenic steroids (AAS) increase libido and sexual behavior, but the underlying behavioral mechanisms are unclear. One way AAS may enhance expression of sexual behavior is by increasing the willingness to work for sex. In the present study, sexually-experienced male rats received daily injections of testosterone at supraphysiologic doses (7.5 mg/kg in water with 13% cyclodextrin) or vehicle and were tested for appetitive sexual behavior measured by operant responding for access to an estrous female. Initially, rats were trained in their home cage to respond on a nose-poke under a 10-min fixed-interval schedule for food reward. Once rats achieved stable response rates, the food was replaced by a female, followed by mating for 10 min. There was no effect of testosterone on operant responding for food (28.1 ± 4.4 responses/10 min for testosterone, 30.6 ± 4.3 for vehicle) or sex (35.0 ± 4.0 responses/10 min for testosterone, 37.3 ± 5.2 for vehicle). However, rats made significantly more responses for sex than for food (p < 0.05), and responses for food and sex were positively correlated among individuals (R(2) = 0.6). Additional groups of rats were trained to respond on a lever for the female under a 2nd-order schedule of reinforcement, where 5 responses opened a door to show the female for 5s. After 15 door openings, the male gained access to the female. There was no effect of testosterone on time to complete 75 responses: 38.4 ± 7.8 min for vehicle controls vs 43.3 ± 6.6 min for testosterone-treated rats (p > 0.05). These findings suggest that chronic high-dose testosterone does not enhance appetitive drive for sexual behavior.
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Affiliation(s)
- Jessica Y Kim
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Ruth I Wood
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
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Hildebrandt T, Shope S, Varangis E, Klein D, Pfaff DW, Yehuda R. Exercise reinforcement, stress, and β-endorphins: an initial examination of exercise in anabolic-androgenic steroid dependence. Drug Alcohol Depend 2014; 139:86-92. [PMID: 24690349 PMCID: PMC4039319 DOI: 10.1016/j.drugalcdep.2014.03.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/06/2014] [Accepted: 03/06/2014] [Indexed: 12/14/2022]
Abstract
BACKGROUND Anabolic-androgenic steroids (AASs) are abused primarily in the context of intense exercise and for the purposes of increasing muscle mass as opposed to drug-induced euphoria. AASs also modulate the HPA axis and may increase the reinforcing value of exercise through changes to stress hormone and endorphin release. To test this hypothesis, 26 adult males drawn from a larger study on AAS use completed a progressive ratio task designed to examine the reinforcing value of exercise relative to financial reinforcer. METHOD Sixteen experienced and current users (8 on-cycle, 8 off-cycle) and 10 controls matched on quantity×frequency of exercise, age, and education abstained from exercise for 24 h prior to testing and provided 24-h cortisol, plasma cortisol, ACTH, β-endorphin samples, and measures of mood, compulsive exercise, and body image. RESULTS Between group differences indicated that on-cycle AAS users had the highest β-endorphin levels, lowest cortisol levels, higher ACTH levels than controls. Conversely, off-cycle AAS users had the highest cortisol and ACTH levels, but the lowest β-endorphin levels. Exercise value was positively correlated with β-endorphin and symptoms of AAS dependence. CONCLUSION The HPA response to AASs may explain why AASs are reinforcing in humans and exercise may play a key role in the development of AAS dependence.
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Affiliation(s)
- Tom Hildebrandt
- Department of Psychiatry, Ichan School of School of Medicine at Mount Sinai, New York, NY, USA.
| | - Sydney Shope
- Department of Psychiatry, Ichan School of School of Medicine at Mount Sinai, New York, NY
| | - Eleanna Varangis
- Department of Psychiatry, Ichan School of School of Medicine at Mount Sinai, New York, NY
| | - Diane Klein
- Department of Psychiatry, New York University, New York, NY
| | | | - Rachel Yehuda
- Department of Psychiatry, Ichan School of School of Medicine at Mount Sinai, New York, NY,James J. Peters Veterans Affairs Medical Center, Bronx, New York
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Weierstall R, Moran J, Giebel G, Elbert T. Testosterone reactivity and identification with a perpetrator or a victim in a story are associated with attraction to violence-related cues. INTERNATIONAL JOURNAL OF LAW AND PSYCHIATRY 2014; 37:304-312. [PMID: 24367977 DOI: 10.1016/j.ijlp.2013.11.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND Recent field research has demonstrated that an attraction to aggressive behavior and cruelty is common among combatants and perpetrators involved in organized violence. The biological basis of this appetitive perception of aggression in humans has to date not been studied. AIMS We examined testosterone as a potential hormonal moderator during induction of specifically appetitive aggressive behavior in the laboratory. METHOD To activate physiological responding related to appetitive aggression, 145 university students (72 women) listened to tape recordings of variants of a violent story. The perspective of the listener in the story was randomized between subjects. Participants were required to either identify as perpetrator, neutral observer, or victim. We assessed changes in saliva testosterone in response to the story. Subsequently, a series of pictorial stimuli (IAPS) with different valence ratings was presented and participants determined the length of viewing time with a button click. This viewing time for negative IAPS was assessed as a dependent variable indicating level of interest in violent scenes. RESULTS Men identified themselves with the perpetrator more than women irrespective of the particular perspective presented by the story. Men who responded with an increase in saliva testosterone when adopting the perpetrator perspective chose to view the negative IAPS pictures for longer intervals than participants in other conditions or those who did not exhibit a release in testosterone. CONCLUSIONS Testosterone moderates attraction to cruel and violent cues in men, as indicated by extended deliberate viewing of violence cues.
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Affiliation(s)
| | - James Moran
- University of Konstanz, Department of Psychology, Germany
| | - Gilda Giebel
- University of Konstanz, Department of Psychology, Germany
| | - Thomas Elbert
- University of Konstanz, Department of Psychology, Germany
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Wood RI, Armstrong A, Fridkin V, Shah V, Najafi A, Jakowec M. 'Roid rage in rats? Testosterone effects on aggressive motivation, impulsivity and tyrosine hydroxylase. Physiol Behav 2013; 110-111:6-12. [PMID: 23266798 PMCID: PMC3615053 DOI: 10.1016/j.physbeh.2012.12.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 11/08/2012] [Accepted: 12/12/2012] [Indexed: 11/26/2022]
Abstract
In humans and animals, anabolic-androgenic steroids (AAS) increase aggression, but the underlying behavioral mechanisms are unclear. AAS may increase the motivation to fight. Alternatively, AAS may increase impulsive behavior, consistent with the popular image of 'roid rage. To test this, adolescent male rats were treated chronically with testosterone (7.5mg/kg) or vehicle and tested for aggressive motivation and impulsivity. Rats were trained to respond on a nose-poke on a 10 min fixed-interval schedule for the opportunity to fight in their home cage with an unfamiliar rat. Although testosterone increased aggression (6.3±1.3 fights/5 min vs 2.4±0.8 for controls, p<0.05), there was no difference in operant responding (28.4±1.6 nose-pokes/10 min for testosterone, 32.4±7.0 for vehicle). This suggests that testosterone does not enhance motivation for aggression. To test for impulsivity, rats were trained to respond for food in a delay-discounting procedure. In an operant chamber, one lever delivered one food pellet immediately, the other lever gave 4 pellets after a delay (0, 15, 30 or 45 s). In testosterone- and vehicle-treated rats, body weights and food intake did not differ. However, testosterone-treated rats chose the larger, delayed reward more often (4.5±0.7 times in 10 trials with 45 s delay) than vehicle controls (2.5±0.5 times, p<0.05), consistent with a reduction in impulsive choice. Thus, although chronic high-dose testosterone enhances aggression, this does not include an increase in impulsive behavior or motivation to fight. This is further supported by measurement of tyrosine hydroxylase (TH) by Western immunoblot analysis in brain regions important for motivation (nucleus accumbens, Acb) and executive function (medial prefrontal cortex, PFC). There were no differences in TH between testosterone- and vehicle-treated rats in Acb or PFC. However, testosterone significantly reduced TH (to 76.9±3.1% of controls, p<0.05) in the caudate-putamen, a brain area important for behavioral inhibition, motor control and habit learning.
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Affiliation(s)
- Ruth I Wood
- Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, Los Angeles, CA 90033, USA.
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Testosterone dynamics during encounter: role of emotional factors. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2012; 198:485-94. [DOI: 10.1007/s00359-012-0726-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 03/27/2012] [Accepted: 04/06/2012] [Indexed: 10/28/2022]
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Novak CM, Burghardt PR, Levine JA. The use of a running wheel to measure activity in rodents: relationship to energy balance, general activity, and reward. Neurosci Biobehav Rev 2012; 36:1001-1014. [PMID: 22230703 DOI: 10.1016/j.neubiorev.2011.12.012] [Citation(s) in RCA: 219] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 12/07/2011] [Accepted: 12/22/2011] [Indexed: 12/21/2022]
Abstract
Running wheels are commonly employed to measure rodent physical activity in a variety of contexts, including studies of energy balance and obesity. There is no consensus on the nature of wheel-running activity or its underlying causes, however. Here, we will begin by systematically reviewing how running wheel availability affects physical activity and other aspects of energy balance in laboratory rodents. While wheel running and physical activity in the absence of a wheel commonly correlate in a general sense, in many specific aspects the two do not correspond. In fact, the presence of running wheels alters several aspects of energy balance, including body weight and composition, food intake, and energy expenditure of activity. We contend that wheel-running activity should be considered a behavior in and of itself, reflecting several underlying behavioral processes in addition to a rodent's general, spontaneous activity. These behavioral processes include defensive behavior, predatory aggression, and depression- and anxiety-like behaviors. As it relates to energy balance, wheel running engages several brain systems-including those related to the stress response, mood, and reward, and those responsive to growth factors-that influence energy balance indirectly. We contend that wheel-running behavior represents factors in addition to rodents' tendency to be physically active, engaging additional neural and physiological mechanisms which can then independently alter energy balance and behavior. Given the impact of wheel-running behavior on numerous overlapping systems that influence behavior and physiology, this review outlines the need for careful design and interpretation of studies that utilize running wheels as a means for exercise or as a measurement of general physical activity.
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Affiliation(s)
- Colleen M Novak
- Department of Biological Sciences, Kent State University, PO Box 5190, 222 Cunningham Hall, Kent, OH 44242, United States
| | | | - James A Levine
- Mayo Clinic, Endocrine Research Unit, Rochester, MN 55905, United States
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What can allostasis tell us about anabolic-androgenic steroid addiction? Dev Psychopathol 2011; 23:907-19. [PMID: 21756441 DOI: 10.1017/s0954579411000393] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Anabolic-androgenic steroids (AASs) are synthetic hormones used by individuals who want to look better or perform better in athletics and at the gym. Their use raises an interesting paradox in which drug use is associated with a number of health benefits, but also the possibility of negative health consequences. Existing models of AAS addiction follow the traditional framework of drug abuse and dependence, which suggest that harmful use occurs as a result of the drug's ability to hijack the motivation-reward system. However, AASs, unlike typical drugs of abuse, are not used for acute intoxication effects or euphoria. Rather, AASs are used to affect the body through changes to the musculoskeletal system and the hypothalamic-pituitary-gonadal axis as opposed to stimulating the reward system. We offer an allostatic model of AAS addiction to resolve this inconsistency between traditional drug addiction and AAS addiction. This allostatic framework provides a way to (a) incorporate exercise into AAS misuse, (b) identify where AAS use transitions from recreational use into a drug problem, and (c) describe individual differences in vulnerability or resilience to AASs. Implications for this model of AAS addiction are discussed.
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Wood RI, Vertelkina NV, Antzoulatos E. Testosterone as a discriminative stimulus in male rats. Pharmacol Biochem Behav 2011; 100:185-90. [PMID: 21893083 PMCID: PMC3183107 DOI: 10.1016/j.pbb.2011.08.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 08/12/2011] [Accepted: 08/22/2011] [Indexed: 11/30/2022]
Abstract
Testosterone and other anabolic-androgenic steroids (AAS) are reinforcing in animals, as determined by conditioned place preference or self-administration. Most drugs of abuse produce subjective effects on mood and perception that initiate and maintain drug taking. Whether AAS have similar effects is not known. Food-restricted male Sprague-Dawley rats (n=9) were tested for their ability to discriminate an injection of testosterone from the β-cyclodextrin vehicle using a standard two-lever operant paradigm. In drug discrimination, animals use the subjective effects of drug or vehicle to select the appropriate lever to obtain food pellets under an FR10 schedule of reinforcement. All rats demonstrated vigorous responding for food (1415.1±76.1 responses/20 min) with 94.9% of responses on the active lever. For the first 30 days, rats received 1mg/kg testosterone sc 30 min before testing. On Day 14, one rat achieved the discrimination criteria of 9/10 consecutive days with >90% responses on the active lever and ≤5 responses on the inactive lever before the first reinforcement. Subsequently, rats were tested with testosterone at different doses (2, 7.5, 15 mg/kg at 30 min before testing) and times (2mg/kg at 30 or 60 min before testing), each for 20 days. One additional rat demonstrated successful discrimination at Day 54 with 2mg/kg testosterone 60 min before testing. The remaining 7 rats failed to discriminate testosterone within 110 days. When analyzed according to less-stringent standards, 4 additional rats met criteria for testosterone discrimination. However, continued performance was not stable. Thus, testosterone was unable to consistently support drug discrimination. We conclude that testosterone does not produce rapid interoceptive effects (NIH DA12843 to RIW).
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Affiliation(s)
- Ruth I Wood
- Department of Cell & Neurobiology, Keck School of Medicine of the University of Southern California, 1333 San Pablo St. BMT 408, Los Angeles, CA 90033, USA.
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Development and validation of the appearance and performance enhancing drug use schedule. Addict Behav 2011; 36:949-58. [PMID: 21640487 DOI: 10.1016/j.addbeh.2011.05.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Revised: 05/04/2011] [Accepted: 05/05/2011] [Indexed: 11/22/2022]
Abstract
Appearance-and-performance enhancing drug (APED) use is a form of drug use that includes use of a wide range of substances such as anabolic-androgenic steroids (AASs) and associated behaviors including intense exercise and dietary control. To date, there are no reliable or valid measures of the core features of APED use. The present study describes the development and psychometric evaluation of the Appearance and Performance Enhancing Drug Use Schedule (APEDUS) which is a semi-structured interview designed to assess the spectrum of drug use and related features of APED use. Eighty-five current APED using men and women (having used an illicit APED in the past year and planning to use an illicit APED in the future) completed the APEDUS and measures of convergent and divergent validity. Inter-rater agreement, scale reliability, one-week test-retest reliability, convergent and divergent validity, and construct validity were evaluated for each of the APEDUS scales. The APEDUS is a modular interview with 10 sections designed to assess the core drug and non-drug phenomena associated with APED use. All scales and individual items demonstrated high inter-rater agreement and reliability. Individual scales significantly correlated with convergent measures (DSM-IV diagnoses, aggression, impulsivity, eating disorder pathology) and were uncorrelated with a measure of social desirability. APEDUS subscale scores were also accurate measures of AAS dependence. The APEDUS is a reliable and valid measure of APED phenomena and an accurate measure of the core pathology associated with APED use. Issues with assessing APED use are considered and future research is considered.
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Hildebrandt T, Lai JK, Langenbucher JW, Schneider M, Yehuda R, Pfaff DW. The diagnostic dilemma of pathological appearance and performance enhancing drug use. Drug Alcohol Depend 2011; 114:1-11. [PMID: 21115306 PMCID: PMC3039045 DOI: 10.1016/j.drugalcdep.2010.09.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 09/16/2010] [Accepted: 09/18/2010] [Indexed: 12/15/2022]
Abstract
Appearance and performance enhancing drug (APED) use includes the use of a range of pharmacologically distinct substances and concurrent investment in outward appearance or achievement, dietary control, and frequent exercise. A number of existing reviews and conceptual papers have defined pathological forms of APED use within the APED class of anabolic-androgenic steroids (AASs) and using the framework of AAS dependence. We review published data on APED use including human studies of AAS users and identified three defining phenomenological features associated with increased health risk and pathology. These features included (1) polypharmacy or the concurrent use of several pharmacologically distinct substances used to change outward appearance or increase likelihood of personal achievement; (2) significant body image disturbance; (3) rigid practices and preoccupations with diet and exercise. Investigations into the latent structure of APED use suggest these features cluster together in a homogenous group of APED users who have the highest health risk and most psychopathology. These features are discussed in the context of AAS dependence and problems with defining classic tolerance-withdrawal symptoms among APED users. Suggestions for a resolution and outline for future research needed to determine the best system for identifying and diagnosing pathological APED use are discussed.
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Affiliation(s)
- Tom Hildebrandt
- Eating and Weight Disorders Program, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1230, New York, NY 10029, USA.
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Sato SM, Johansen JA, Jordan CL, Wood RI. Membrane androgen receptors may mediate androgen reinforcement. Psychoneuroendocrinology 2010; 35:1063-73. [PMID: 20137860 PMCID: PMC2891198 DOI: 10.1016/j.psyneuen.2010.01.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 11/13/2009] [Accepted: 01/14/2010] [Indexed: 11/28/2022]
Abstract
Anabolic-androgenic steroid (AAS) abuse is widespread. Moreover, AAS are reinforcing, as shown by self-administration in rodents. However, the receptors that transduce the reinforcing effects of AAS are unclear. AAS may bind to classical nuclear androgen receptors (ARs) or membrane receptors. We used two approaches to examine the role of nuclear ARs in AAS self-administration. First, we tested androgen self-administration in rats with the testicular feminization mutation (Tfm), which interferes with androgen binding. If nuclear ARs are essential for AAS self-administration, Tfm males should not self-administer androgens. Tfm males and wild-type (WT) littermates self-administered the non-aromatizable androgen dihydrotestosterone (DHT) or vehicle intracerebroventricularly (ICV) at fixed-ratio (FR) schedules up to FR5. Both Tfm and WT rats acquired a preference for the active nose-poke during DHT self-administration (66.4+/-9.6 responses/4 h for Tfm and 79.2+/-11.5 for WT responses/4 h), and nose-pokes increased as the FR requirement increased. Preference scores were significantly lower in rats self-administering vehicle (42.3+/-5.3 responses/4 h for Tfm and 19.1+/-4.0 responses/4 h for WT). We also tested self-administration of DHT conjugated to bovine serum albumin (BSA) at C3 and C17, which is limited to actions at the cell surface. Hamsters were allowed to self-administer DHT, BSA and DHT-BSA conjugates for 15 days at FR1. The hamsters showed a significant preference for DHT (18.0+/-4.1 responses/4 h) or DHT-BSA conjugates (10.0+/-3.7 responses/4 h and 21.0+/-7.2 responses/4 h), but not for BSA (2.5+/-2.4 responses/4 h). Taken together, these data demonstrate that nuclear ARs are not required for androgen self-administration. Furthermore, androgen self-administration may be mediated by plasma membrane receptors.
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Affiliation(s)
- Satoru M. Sato
- Department of Cell & Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | - Jamie A. Johansen
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
| | - Cynthia L. Jordan
- Neuroscience Program, Michigan State University, East Lansing, MI 48824,Department of Psychology, Michigan State University, East Lansing, MI 48824
| | - Ruth I. Wood
- Department of Cell & Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
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Attenuating effects of testosterone on depressive-like behavior in the forced swim test in healthy male rats. Brain Res Bull 2009; 79:182-6. [DOI: 10.1016/j.brainresbull.2009.02.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 02/09/2009] [Accepted: 02/24/2009] [Indexed: 11/19/2022]
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Wood RI. Anabolic-androgenic steroid dependence? Insights from animals and humans. Front Neuroendocrinol 2008; 29:490-506. [PMID: 18275992 PMCID: PMC2585375 DOI: 10.1016/j.yfrne.2007.12.002] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 12/21/2007] [Accepted: 12/25/2007] [Indexed: 11/21/2022]
Abstract
Anabolic-androgenic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, with negative health consequences. As a result, in 1991 testosterone and related AAS were declared controlled substances. However, the relative abuse and dependence liability of AAS have not been fully characterized. In humans, it is difficult to separate the direct psychoactive effects of AAS from reinforcement due to their systemic anabolic effects. However, using conditioned place preference and self-administration, studies in animals have demonstrated that AAS are reinforcing in a context where athletic performance is irrelevant. Furthermore, AAS share brain sites of action and neurotransmitter systems in common with other drugs of abuse. In particular, recent evidence links AAS with opioids. In humans, AAS abuse is associated with prescription opioid use. In animals, AAS overdose produces symptoms resembling opioid overdose, and AAS modify the activity of the endogenous opioid system.
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Affiliation(s)
- Ruth I Wood
- Department of Cell & Neurobiology, Keck School of Medicine of the University of Southern California, 1333 San Pablo Street, BMT 401, Los Angeles, CA 90033, USA.
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Sato SM, Schulz KM, Sisk CL, Wood RI. Adolescents and androgens, receptors and rewards. Horm Behav 2008; 53:647-58. [PMID: 18343381 PMCID: PMC2435368 DOI: 10.1016/j.yhbeh.2008.01.010] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Revised: 01/24/2008] [Accepted: 01/25/2008] [Indexed: 01/08/2023]
Abstract
Adolescence is associated with increases in pleasure-seeking behaviors, which, in turn, are shaped by the pubertal activation of the hypothalamo-pituitary-gonadal axis. In animal models of naturally rewarding behaviors, such as sex, testicular androgens contribute to the development and expression of the behavior in males. To effect behavioral maturation, the brain undergoes significant remodeling during adolescence, and many of the changes are likewise sensitive to androgens, presumably acting through androgen receptors (AR). Given the delicate interaction of gonadal hormones and brain development, it is no surprise that disruption of hormone levels during this sensitive period significantly alters adolescent and adult behaviors. In male hamsters, exposure to testosterone during adolescence is required for normal expression of adult sexual behavior. Males deprived of androgens during puberty display sustained deficits in mating. Conversely, androgens alone are not sufficient to induce mating in prepubertal males, even though brain AR are present before puberty. In this context, wide-spread use of anabolic-androgenic steroids (AAS) during adolescence is a significant concern. AAS abuse has the potential to alter both the timing and the levels of androgens in adolescent males. In hamsters, adolescent AAS exposure increases aggression, and causes lasting changes in neurotransmitter systems. In addition, AAS are themselves reinforcing, as demonstrated by self-administration of testosterone and other AAS. However, recent evidence suggests that the reinforcing effects of androgens may not require classical AR. Therefore, further examination of interactions between androgens and rewarding behaviors in the adolescent brain is required for a better understanding of AAS abuse.
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Affiliation(s)
- Satoru M. Sato
- Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, Los Angeles, CA 90033
| | - Kalynn M. Schulz
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI 48824
| | - Cheryl L. Sisk
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI 48824
| | - Ruth I. Wood
- Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, Los Angeles, CA 90033
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Triemstra JL, Sato SM, Wood RI. Testosterone and nucleus accumbens dopamine in the male Syrian hamster. Psychoneuroendocrinology 2008; 33:386-94. [PMID: 18249072 PMCID: PMC2275113 DOI: 10.1016/j.psyneuen.2007.12.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 12/14/2007] [Accepted: 12/17/2007] [Indexed: 11/15/2022]
Abstract
Most drugs of abuse increase dopamine (DA) in nucleus accumbens (Acb). However, the effects of anabolic androgenic steroids (AAS) on Acb DA have not been examined. We determined the effects of subcutaneous (sc) testosterone (T) on Acb DA in male hamsters. The effects of sc amphetamine were also examined for comparison. In addition, Acb DA was evaluated during intracerebroventricular (ICV) T infusion, designed to mimic T intake during ICV T self-administration in drug-naïve and drug-preexposed animals. Acb DA was measured using in vivo microdialysis and HPLC-EC. T (7.5 or 37.5 mg/kg), amphetamine (1 or 5 mg/kg), or vehicle was injected sc and Acb DA monitored for 4h. In the ICV experiment, T (1 or 2 microg/infusion) or vehicle was infused ICV every 6 min for 4h and Acb DA monitored. ICV T preexposure was accomplished by repeating the same ICV T infusion (1 microg/infusion) daily for 14 days, and T infusion was accompanied by microdialysis on 15th day. Neither sc nor ICV T administration increased Acb DA. At high dose (2 microg/infusion), ICV T decreased Acb DA. Likewise, daily ICV infusion of T for 15 days did not alter Acb DA. In contrast, sc amphetamine significantly increased Acb DA at both doses. Therefore, unlike many drugs of abuse, AAS does not increase Acb DA levels. The reduction in DA at high T doses is likely due to autonomic depressant effects of AAS. We suggest that AAS act via mechanism distinct from those of stimulants, but may share neural substrates with other drugs of abuse.
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Affiliation(s)
| | | | - Ruth I. Wood
- *Address all reprint requests and correspondence to: Ruth I. Wood, Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, 1333 San Pablo St. BMT 401, Los Angeles, CA 90033, Telephone (323) 442-1980, Fax: (323) 442-3466, e-mail:
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Novak CM, Levine JA. Central neural and endocrine mechanisms of non-exercise activity thermogenesis and their potential impact on obesity. J Neuroendocrinol 2007; 19:923-40. [PMID: 18001322 DOI: 10.1111/j.1365-2826.2007.01606.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The rise in obesity is associated with a decline in the amount of physical activity in which people engage. The energy expended through everyday non-exercise activity, called non-exercise activity thermogenesis (NEAT), has a considerable potential impact on energy balance and weight gain. Comparatively little attention has been paid to the central mechanisms of energy expenditure and how decreases in NEAT might contribute to obesity. In this review, we first examine the sensory and endocrine mechanisms through which energy availability and energy balance are detected that may influence NEAT. Second, we describe the neural pathways that integrate these signals. Lastly, we consider the effector mechanisms that modulate NEAT through the alteration of activity levels as well as through changes in the energy efficiency of movement. Systems that regulate NEAT according to energy balance may be linked to neural circuits that modulate sleep, addiction and the stress response. The neural and endocrine systems that control NEAT are potential targets for the treatment of obesity.
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Affiliation(s)
- C M Novak
- Mayo Clinic, Endocrine Research Unit, Rochester, MN, USA.
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Frye CA, Babson A, Walf AA. Self-administration of 3α-androstanediol increases locomotion and analgesia and decreases aggressive behavior of male hamsters. Pharmacol Biochem Behav 2007; 86:415-21. [PMID: 16828856 DOI: 10.1016/j.pbb.2006.05.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 04/20/2006] [Accepted: 05/30/2006] [Indexed: 11/18/2022]
Abstract
Androgens, such as testosterone (T), can have reinforcing effect, which may be due in part to actions of T's metabolite, 3alpha-androstanediol (3alpha-diol). To investigate rewarding effects of 3alpha-diol, gonadally intact adult male hamsters were given a two-bottle choice test to determine the amount of 3alpha-diol that would be self-administered over 4 days of exposure. After 2 days of habituation and 4 days of monitoring of consumption, hamsters were tested in an activity monitor and the open field (locomotion/exploration), paw lick (analgesia) and resident-intruder (aggression) tasks. Hamsters consumed significantly more 3alpha-diol than vehicle in the two-bottle choice test. Hamsters that were allowed to self-administer 3alpha-diol made significantly more beam breaks and total entries in the open field had increased latencies to pawlick, and engaged in significantly fewer attacks, than did hamsters with access to vehicle alone. Hamsters that self-administered 3alpha-diol had higher levels of 3alpha-diol in serum, hippocampus, prefrontal cortex, striatum and midbrain than did hamsters with access to vehicle alone. Together, these data suggest that 3alpha-diol may have rewarding effects.
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Affiliation(s)
- Cheryl A Frye
- Department of Psychology, The University at Albany-SUNY, 1400 Washington Avenue, Albany, NY 12222, USA.
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Ballard CL, Wood RI. Partner preference in male hamsters: steroids, sexual experience and chemosensory cues. Physiol Behav 2007; 91:1-8. [PMID: 17316716 PMCID: PMC1924919 DOI: 10.1016/j.physbeh.2007.01.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 12/20/2006] [Accepted: 01/10/2007] [Indexed: 11/19/2022]
Abstract
This study investigated the effects of gonadal steroids on sexual motivation in male Syrian hamsters, using partner preference as a model. Male hamsters were assigned to 5 groups: control (n=4), Intact-->Orchx (n=8), Orchx-->Orchx+T (n=7), olfactory bulbectomy (BulbX, n=5), and vomeronasal organ lesion (VnoX, n=8). Each male was tested for partner preference before and after sexual experience. Unlike rats, sexually-inexperienced gonad-intact male hamsters preferred the receptive female to a stimulus male. However, sexual experience did not enhance preference for the stimulus female. Castration (Orchx) reduced sexual motivation: Orchx males showed no significant preference for the stimulus female. Subsequently, intact males were castrated (Intact-->Orchx) and Orchx males received a testosterone implant (Orchx-->Orchx+T) to determine the time course of gonadal hormones on partner preference and mating behavior. Partner preference changed significantly in both groups within 6 weeks. In Intact-->Orchx males, preference for the stimulus female decreased while Orchx-->Orchx+T males increased their preference for the stimulus female. However, significant changes in mating behavior preceded the alterations in partner preference. Chemosensory cues are also important for partner preference. After BulbX, preference for the stimulus female significantly decreased. However, VnoX failed to block partner preference. These results show that partner preference may be even more dependent on testosterone than is sexual behavior. Furthermore, while chemosensory cues are essential for sexual motivation, the vomeronasal organ is not required for partner preference.
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Affiliation(s)
- Cortney L Ballard
- Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, 1333 San Pablo St., BMT 401, Los Angeles, CA 90033, United States
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Frye CA. Some rewarding effects of androgens may be mediated by actions of its 5alpha-reduced metabolite 3alpha-androstanediol. Pharmacol Biochem Behav 2006; 86:354-67. [PMID: 17112575 PMCID: PMC1857333 DOI: 10.1016/j.pbb.2006.10.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 07/24/2006] [Accepted: 10/03/2006] [Indexed: 11/22/2022]
Abstract
The abuse of anabolic-androgenic steroids (AS) is a growing problem; however, the effects and mechanisms underlying their addictive effects are not well understood. Research findings regarding androgen abuse in people and hedonic effects of androgens in laboratory rats are reviewed. Androgens, like other steroids, can have traditional actions via cognate intracellular steroid receptors, as well as other substrates. Our recent results indicate that testosterone (T) metabolites may have actions in part via gamma-aminobutyric acid (GABA)(A)/benzodiazepine receptor complexes (GBRs) and/or dopaminergic neurons in the nucleus accumbens, to mediate T's positive hedonic states. This may provide the basis for positive reinforcing effects of androgen seeking and use behavior. Following a comprehensive review of the background literature, our findings are presented that have explored the extent to which metabolites of T mediate euphorogenic effects of androgens by acting in the nucleus accumbens. Then results regarding whether GBRs are necessary substrates for androgens' positive hedonic effects are discussed. Lastly, research that addresses if dopaminergic neurons in the nucleus accumbens are necessary for these effects of androgens are discussed. This review provides a comprehensive examination of the hedonic properties and abuse/addiction potential of androgens and the putative mechanisms underlying these effects.
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Affiliation(s)
- Cheryl A Frye
- Department of Psychology, Centers for Neuroscience and Life Sciences Research Building, Room 1058, The University at Albany-State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
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DiMeo AN, Wood RI. Self-administration of estrogen and dihydrotestosterone in male hamsters. Horm Behav 2006; 49:519-26. [PMID: 16388806 DOI: 10.1016/j.yhbeh.2005.11.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2005] [Revised: 11/03/2005] [Accepted: 11/16/2005] [Indexed: 10/25/2022]
Abstract
Anabolic-androgenic steroids (AAS) are drugs of abuse. Previous studies have shown that male and female hamsters self-administer testosterone (T) and other AAS, suggesting that androgens are reinforcing in a context where athletic performance is irrelevant. AAS are synthetic derivatives of T, which may be aromatizable to estrogen and/or reducible to dihydrotestosterone (DHT). However, we do not know which metabolites of T are reinforcing. To determine if DHT, estradiol (E(2)), or DHT + E(2) are reinforcing, we tested intracerebroventricular (icv) self-administration in male hamsters. The hypothesis was that androgen reinforcement is sensitive to both androgenic and estrogenic T metabolites. If so, hamsters would self-administer DHT, E(2), and DHT + E(2). Twenty four castrated male hamsters (n = 8/group) received icv cannulas and sc T implants for physiologic androgen replacement. One week later, hamsters self-administered DHT (0.1, 1.0, 2.0 microg/microl), E(2) (0.001, 0.01, 0.02 microg/microl), or DHT + E(2), each for 8 days in increasing concentration (4 h/day). Operant chambers were equipped with an active and inactive nose-poke. At the medium concentration, hamsters self-administered DHT (active nose-poke: 47.9 +/- 13.9 responses/4 h vs. inactive: 18.7 +/- 4.8), E(2) (active: 44.8 +/- 14.9 vs. inactive: 16.6 +/- 2.6), and DHT + E(2) (active: 19.1 +/- 2.4 vs. inactive: 10.4 +/- 2.4, P < 0.05). At the highest concentration, males self-administered DHT (active: 28.3 +/- 7.7 vs. inactive: 15.0 +/- 3.5, P < 0.05) and DHT + E(2) (active: 22.6 +/- 3.8 vs. inactive: 11.6 +/- 2.5, P < 0.05), but not E(2). Hamsters did not self-administer the lowest concentrations of DHT, E(2), or DHT + E(2). These results support our hypothesis that both androgenic and estrogenic T metabolites are reinforcing. Together, they do not exert synergistic effects.
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Affiliation(s)
- Anita N DiMeo
- Neuroscience Program, Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, 1333 San Pablo St., BMT 401, 90033, USA
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DiMeo AN, Wood RI. Circulating androgens enhance sensitivity to testosterone self-administration in male hamsters. Pharmacol Biochem Behav 2005; 79:383-9. [PMID: 15501316 DOI: 10.1016/j.pbb.2004.08.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 08/19/2004] [Accepted: 08/26/2004] [Indexed: 11/20/2022]
Abstract
Young adult men are more likely to abuse steroids than individuals with low testosterone, including women, boys and older men. This suggests that circulating testosterone may enhance sensitivity to exogenous androgens. This hypothesis was tested using intracerebroventricular (i.c.v.) testosterone self-administration in orchidectomized males without testosterone (Orchx, n=8) and in orchidectomized males with chronic physiologic testosterone replacement (Orchx+T, n=8). Beginning 1 week after surgery, hamsters self-administered testosterone for 4 h/day in operant chambers at three doses (0.1, 1.0 and 2.0 microg/microl), each for 8 days. Afterwards, testosterone was replaced with vehicle for 8 days to test extinction. At 1.0 and 2.0 microg/microl, Orchx+T and Orchx males self-administered similar amounts of testosterone. However, at 0.1 microg/microl testosterone, only Orchx+T males showed a significant preference for the active nose-poke (Orchx+T active: 35.1+/-8.4 responses/4 h [mean+/-S.E.M.] vs. inactive: 16.5+/-1.7 responses/4 h, p<0.05; Orchx active: 16.7+/-4.9 responses/4 h vs. inactive: 13.5+/-3.1 responses/4 h, p>0.05). There was little change in operant behavior during extinction in Orchx+T males. However, when vehicle replaced testosterone, Orchx males extinguished their preference for the active nose-poke hole by day 6. These results support our hypothesis that circulating androgens enhance sensitivity to testosterone self-administration.
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Affiliation(s)
- Anita N DiMeo
- Neuroscience Program, Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, 1333 San Pablo Street, BMT 401, Los Angeles, CA 90033, USA
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Ballard CL, Wood RI. Intracerebroventricular Self-Administration of Commonly Abused Anabolic-Androgenic Steroids in Male Hamsters (Mesocricetus auratus): Nandrolone, Drostanolone, Oxymetholone, and Stanozolol. Behav Neurosci 2005; 119:752-8. [PMID: 15998196 DOI: 10.1037/0735-7044.119.3.752] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Previous studies by the authors have shown voluntary intracerebroventricular (icv) testosterone self-administration in hamsters (Mesocricetus auratus). Here, the authors compared icv self-administration of 4 anabolic steroids (drostanolone, nandrolone, oxymetholone, and stanozolol) at 0.1, 1.0, and 2.0 microg/microl, each for 8 days. Males (n=8/group) showed the highest levels of operant behavior for injectable steroids (drostanolone, nandrolone) compared with orally active androgens (oxymetholone, stanozolol). For nandrolone, responses on the active and inactive nose-pokes averaged 22.3 +/- 4.6/4 hr and 10.7 +/- 2.0/4 hr, respectively. Responding for drostanolone was similar. Males self-administering oxymetholone or stanozolol did not prefer the active nose-poke. These data demonstrate that injectable androgens are more reinforcing than oral steroids.
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Affiliation(s)
- Cortney L Ballard
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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Triemstra JL, Wood RI. Testosterone self-administration in female hamsters. Behav Brain Res 2004; 154:221-9. [PMID: 15302128 DOI: 10.1016/j.bbr.2004.02.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2003] [Revised: 02/06/2004] [Accepted: 02/16/2004] [Indexed: 11/16/2022]
Abstract
Abuse of anabolic-androgenic steroids (AAS) is a growing public health concern. In addition to their anabolic effects, steroids are also reinforcing as demonstrated by testosterone self-administration in male hamsters. However, steroid use in women lags behind that in men. Are androgens also rewarding in females? We determined if female hamsters voluntarily consume testosterone by intracerebroventricular (i.c.v.) self-administration in an operant chamber. Twelve ovary-intact female hamsters self-administering testosterone (1.0 microg/microl) i.c.v. for 19.1 +/- 2.3 days developed a significant preference (P < 0.05) for the active nose-poke (31.5 +/- 6.1 nose-pokes/4 h) over the inactive nose-poke (12.5 +/- 1.1 nose-pokes/4 h). Operant behavior in females was similar to that reported previously for male hamsters. Estrous cycles became irregular 9.6 +/- 2.3 days after the start of self-administration. Regular cycles resumed 13.7 +/- 2.6 days after testosterone was discontinued. To determine the effect of ovarian steroids on androgen self-administration, females were ovariectomized (OVX) and allowed to self-administer testosterone for 10.8 +/- 0.5 days. Afterwards, estrogen was replaced, and self-administration continued for an additional 9.7 +/- 0.6 days. OVX females maintained their preference for the active (23.9 +/- 7.0 nose-pokes/4 h) over the inactive nose-poke (12.6 +/- 3.4 nose-pokes/4 h, P < 0.05), and estrogen had no effect on responding for androgen (active: 25.8 +/- 6.5 nose-pokes; inactive: 8.2 +/- 2.0 nose-pokes/4 h, P < 0.05). Estrous female hamsters did not show a significant preference for stimulus males or females when mating was blocked, and testosterone self-administration did not alter partner preference. However, activity in the preference chamber predicted subsequent androgen intake (R(2) = 0.66, P < 0.05). These findings are consistent with the idea that anabolic steroids have inhibitory effects on female reproduction. Moreover, they suggest that sex differences in androgen reward do not underlie sex differences in AAS abuse in humans.
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Affiliation(s)
- Jennifer L Triemstra
- Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, 1333 San Pablo Street, BMT 401, Los Angeles, CA 90033, USA
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Abstract
Are androgens reinforcing? Androgenic-anabolic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, often with negative long-term health consequences. As a result, in 1991, testosterone was declared a controlled substance. Recently, Brower [K.J. Brower, Anabolic steroid abuse and dependence. Curr. Psychiatry Rep. 4 (2002) 377-387.] proposed a two-stage model of AAS dependence. Users initiate steroid use for their anabolic effects on muscle growth. With continued exposure, dependence on the psychoactive effects of AAS develops. However, it is difficult in humans to separate direct psychoactive effects of AAS from the user's psychological dependence on the anabolic effects of AAS. Thus, studies in laboratory animals are useful to explore androgen reinforcement. Testosterone induces a conditioned place preference in rats and mice, and is voluntarily consumed through oral, intravenous, and intracerebroventricular self-administration in hamsters. Active, gonad-intact male and female hamsters will deliver 1 microg/microl testosterone into the lateral ventricles. Indeed, some individuals self-administer testosterone intracerebroventricularly to the point of death. Male rats develop a conditioned place preference to testosterone injections into the nucleus accumbens, an effect blocked by dopamine receptor antagonists. These data suggest that androgen reinforcement is mediated by the brain. Moreover, testosterone appears to act through the mesolimbic dopamine system, a common substrate for drugs of abuse. Nonetheless, androgen reinforcement is not comparable to that of cocaine or heroin. Instead, testosterone resembles other mild reinforcers, such as caffeine, nicotine, or benzodiazepines. The potential for androgen addiction remains to be determined.
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Affiliation(s)
- Ruth I Wood
- Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, 1333 San Pablo Street, BMT 401, Los Angeles, CA 90033, USA.
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Wood RI, Johnson LR, Chu L, Schad C, Self DW. Testosterone reinforcement: intravenous and intracerebroventricular self-administration in male rats and hamsters. Psychopharmacology (Berl) 2004; 171:298-305. [PMID: 14557917 DOI: 10.1007/s00213-003-1587-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2003] [Accepted: 06/27/2003] [Indexed: 10/26/2022]
Abstract
RATIONALE Anabolic steroids are drugs of abuse. However, the potential for addiction remains unclear. Testosterone induces conditioned place preference in rats and oral self-administration in hamsters. OBJECTIVES To determine if male rats and hamsters consume testosterone by intravenous (IV) or intracerebroventricular (ICV) self-administration. METHODS With each nose-poke in the active hole during daily 4-h tests in an operant conditioning chamber, gonad-intact adult rats and hamsters received 50 microg testosterone in an aqueous solution of beta-cyclodextrin via jugular cannula. The inactive nose-poke hole served as a control. Additional hamsters received vehicle infusions. RESULTS Rats ( n=7) expressed a significant preference for the active nose-poke hole (10.0+/-2.8 responses/4 h) over the inactive hole (4.7+/-1.2 responses/4 h). Similarly, during 16 days of testosterone self-administration IV, hamsters ( n=9) averaged 11.7+/-2.9 responses/4 h and 6.3+/-1.1 responses/4 h in the active and inactive nose-poke holes, respectively. By contrast, vehicle controls ( n=8) failed to develop a preference for the active nose-poke hole (6.5+/-0.5 and 6.4+/-0.3 responses/4 h). Hamsters ( n=8) also self-administered 1 microg testosterone ICV (active hole:39.8+/-6.0 nose-pokes/4 h; inactive hole: 22.6+/-7.1 nose-pokes/4 h). When testosterone was replaced with vehicle, nose-poking in the active hole declined from 31.1+/-7.6 to 11.9+/-3.2 responses/4 h within 6 days. Likewise, reversing active and inactive holes increased nose-poking in the previously inactive hole from 9.1+/-1.9 to 25.6+/-5.4 responses/4 h. However, reducing the testosterone dose from 1 microg to 0.2 microg per 1 microl injection did not change nose-poking. CONCLUSIONS Compared with other drugs of abuse, testosterone reinforcement is modest. Nonetheless, these data support the hypothesis that testosterone is reinforcing.
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Affiliation(s)
- Ruth I Wood
- Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, Los Angeles 90033, USA.
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Clark AS, Henderson LP. Behavioral and physiological responses to anabolic-androgenic steroids. Neurosci Biobehav Rev 2003; 27:413-36. [PMID: 14505684 DOI: 10.1016/s0149-7634(03)00064-2] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone originally designed for therapeutic uses to provide enhanced anabolic potency with negligible androgenic effects. Although AAS continue to be used clinically today, the medical benefits of low therapeutic doses of AAS stand in sharp contrast to the potential health risks associated with the excessive doses self-administered not only by elite athletes and body builders, but by a growing number of recreational users, including adolescent boys and girls. The deleterious effects of AAS on peripheral organs and the incidence of altered behaviors in AAS abusers have been well documented in a number of excellent current reviews for clinical populations. However, a comparable synthesis of nonclinical studies has not been made. Our purpose in this review is to summarize the literature for animal models of the effects of supraphysiological doses of AAS (e.g. those that mimic human abuse regimes) on behaviors and on the neural circuitry for these behaviors. In particular, we have focused on studies in rodents that have examined how AAS alter aggression, sexual behaviors, anxiety, reward, learning, and locomotion and how AAS alter the expression and function of neurotransmitter systems and other signaling molecules that underlie these behaviors.
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Affiliation(s)
- Ann S Clark
- Department of Psychological and Brain Sciences, Dartmouth College, 6207 Moore Hall, Hanover, NH 03755, USA.
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Abstract
Aggression and violence are concerns that engage us across society as moral and cultural issues. They are also critical issues for mental health research--both for survivors and for understanding how such behaviors occur. Interpersonal violence often explodes in deliberate acts of physical force leaving survivors behind with a diminished sense of control that is often shadowed by persistent fear and anxiety. The treatment of the victims is a clear and immediate concern; from their perspectives the medical consequences require effective attention whether they suffered as a result of acts of nature, mental disease, ideology, or combinations of these. At the same time preventing violent behavior from happening in the first place is a compelling challenge for public health research.
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