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Kawashima H, Aono Y, Shimba S, Waddington JL, Saigusa T. Adolescence as a critical period for nandrolone-induced muscular strength in relation to abuse liability, alone and in conjunction with morphine, using accumbal dopamine efflux in freely moving rats. Synapse 2023; 77:e22262. [PMID: 36637118 DOI: 10.1002/syn.22262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/15/2022] [Accepted: 01/08/2023] [Indexed: 01/14/2023]
Abstract
Nandrolone, an anabolic androgenic steroid, is included in the prohibited list of the World Anti-Doping Agency. Drugs of abuse activate brain dopamine neurons and nandrolone has been suspected of inducing dependence. Accordingly, possible critical periods for the effects of nandrolone on muscular strength and dopaminergic activity have been investigated, including the effects of chronically administered nandrolone alone and on morphine-induced increases in dopamine efflux in the nucleus accumbens. Six- or 10-week-old male Sprague-Dawley rats were used. Treatment with nandrolone was initiated in adolescent (6-week-old) and young adult (10-week-old) rats. Nandrolone (5.0 mg/kg s.c.) or sesame oil vehicle was given once daily, on six consecutive days per week, for 3 weeks and then once per day for 4 consecutive days. Nandrolone enhanced the developmental increase in grip strength of 6- but not 10-week-old rats, without altering the developmental increase in body weight of either age group. Using in vivo microdialysis in freely moving 6-week-old rats given nandrolone for 4 weeks, basal accumbal dopamine efflux was unaltered, while the increase in dopamine efflux induced by acute administration of morphine (1.0 mg/kg s.c.) was reduced. The present study provides in vivo evidence that adolescence constitutes a critical period during which repeated administration of nandrolone enhances increases in muscular strength without influencing increases in body weight. Though repeated administration of nandrolone during this period of adolescence did not stimulate in vivo mesolimbic dopaminergic activity, it disrupted stimulation by an opioid, the drug class that is most commonly coabused with nandrolone.
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Grants
- TS,JLW Nakatomi Foundation, Japan
- #21K10124toYA Japan Society for the Promotion of Science
- #21K10081toTS Japan Society for the Promotion of Science
- NihonUniversityPresident'sGrantforSpecifiedInterdisciplinaryResearch(YA,SS,TS) Nihon University
- GrantsfromSuzukiFund(YA,TS)andResearchInstituteofOralScience,NihonUniversitySchoolofDentistryatMatsudo(YW,YA,TS) Nihon University School of Dentistry at Matsudo
- Nakatomi Foundation, Japan, TS, JLW
- Japan Society for the Promotion of Science, #21K10124 to YA, #21K10081 to TS
- Nihon University, Nihon University President's Grant for Specified Interdisciplinary Research (YA, SS, TS)
- Nihon University School of Dentistry at Matsudo, Grants from Suzuki Fund (YA, TS) and Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo (YW, YA, TS)
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Affiliation(s)
- Hiroki Kawashima
- Oral Molecular Pharmacology, Nihon University Graduate School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - Yuri Aono
- Department of Pharmacology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - Shigeki Shimba
- Laboratory of Health Science, Nihon University School of Pharmacy, Funabashi, Chiba, Japan
| | - John L Waddington
- School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences, Dublin, Ireland
| | - Tadashi Saigusa
- Oral Molecular Pharmacology, Nihon University Graduate School of Dentistry at Matsudo, Matsudo, Chiba, Japan
- Department of Pharmacology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
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Hippocampal and amygdalar increased BDNF expression in the extinction of opioid-induced place preference. IBRO Neurosci Rep 2022; 13:402-409. [PMID: 36275846 PMCID: PMC9580243 DOI: 10.1016/j.ibneur.2022.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/23/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022] Open
Abstract
The opioid crisis was exacerbated during the COVID-19 pandemic in the United States with alarming statistics about overdose-related deaths. Current treatment options, such as medication assisted treatments, have been unable to prevent relapse in many patients, whereas cue-based exposure therapy have had mixed results in human trials. To improve patient outcomes, it is imperative to develop animal models of addiction to understand molecular mechanisms and identify potential therapeutic targets. We previously found increased brain derived neurotrophic factor (bdnf) transcript in the ventral striatum/nucleus accumbens (VS/NAc) of rats that extinguished morphine-induced place preference. Here, we expand our study to determine whether BDNF protein expression was modulated in mesolimbic brain regions of the reward system in animals exposed to extinction training. Drug conditioning and extinction sessions were followed by Western blots for BDNF in the hippocampus (HPC), amygdala (AMY) and VS/NAc. Rears, as a measure of withdrawal-induced anxiety were also measured to determine their impact on extinction. Results showed that animals who received extinction training and successfully extinguished morphine CPP significantly increased BDNF in the HPC when compared to animals deprived of extinction training (sham-extinction). This increase was not significant in animals who failed to extinguish (extinction-resistant). In AMY, all extinction-trained animals showed increased BDNF, regardless of behavior phenotype. No BDNF modulation was observed in the VS/NAc. Finally, extinction-trained animals showed no difference in rears regardless of extinction outcome, suggesting that anxiety elicited by drug withdrawal did not significantly impact extinction of morphine CPP. Our results suggest that BDNF expression in brain regions of the mesolimbic reward system could play a key role in extinction of opioid-induced maladaptive behaviors and represents a potential therapeutic target for future combined pharmacological and extinction-based therapies.
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Bontempi L, Bonci A. µ-Opioid receptor-induced synaptic plasticity in dopamine neurons mediates the rewarding properties of anabolic androgenic steroids. Sci Signal 2020; 13:13/647/eaba1169. [PMID: 32873724 DOI: 10.1126/scisignal.aba1169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Anabolic androgenic steroids (AAS) have medical utility but are often abused, and the effects of AAS on reward circuits in the brain have been suggested to lead to addiction. We investigated the previously reported correlations between AAS and the endogenous μ-opioid system in the rewarding properties of AAS in mice. We found that a single injection of a supraphysiological dose of natural or synthetic AAS strengthened excitatory synaptic transmission in putative ventral tegmental area (VTA) dopaminergic neurons. This effect was associated with the activation of μ-opioid receptors (MORs) and an increase in β-endorphins released into the VTA and the plasma. Irreversible blockade of MORs in the VTA counteracted two drug-seeking behaviors, locomotor activity and place preference. These data suggest that AAS indirectly stimulate a dopaminergic reward center of the brain through activation of endogenous opioid signaling and that this mechanism mediates the addictive effects of AAS.
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Affiliation(s)
- Leonardo Bontempi
- Intramural Research Program, Synaptic Plasticity Section, National Institute on Drug Abuse, Baltimore, MD 21224, USA.
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Martínez-Rivera FJ, Martínez NA, Martínez M, Ayala-Pagán RN, Silva WI, Barreto-Estrada JL. Neuroplasticity transcript profile of the ventral striatum in the extinction of opioid-induced conditioned place preference. Neurobiol Learn Mem 2019; 163:107031. [PMID: 31173919 DOI: 10.1016/j.nlm.2019.107031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 05/27/2019] [Accepted: 06/03/2019] [Indexed: 01/03/2023]
Abstract
Persistent drug-seeking behavior has been associated with deficits in neural circuits that regulate the extinction of addictive behaviors. Although there is extensive data that associates addiction phases with neuroplasticity changes in the reward circuit, little is known about the underlying mechanisms of extinction learning of opioid associated cues. Here, we combined morphine-conditioned place preference (CPP) with real-time polymerase chain reaction (RT-PCR) to identify the effects of extinction training on the expression of genes (mRNAs) associated with synaptic plasticity and opioid receptors in the ventral striatum/nucleus accumbens (VS/NAc). Following morphine extinction training, we identified two animal subgroups showing either extinction (low CPP) or extinction-resistance (high CPP). A third group were conditioned to morphine but did not receive extinction training (sham-extinction; high CPP). RT-PCR results showed that brain derived neurotrophic factor (Bdnf) was upregulated in rats showing successful extinction. Conversely, the lack of extinction training (sham-extinction) upregulated genes associated with kinases (Camk2g), neurotrophins (Ngfr), synaptic connectivity factors (Ephb2), glutamate neurotransmission (Grm8) and opioid receptors (μ1, Δ1). To further identify genes modulated by morphine itself, comparisons with their saline-counterparts were performed. Results revealed that Bdnf was consistently upregulated in the extinction group. Alternatively, widespread gene modulation was observed in the group with lack of extinction training (i.e. Drd2, Cnr1, Creb, μ1, Δ1) and the group showing extinction resistance (i.e. Crem, Rheb, Tnfa). Together, our study builds on the identification of putative genetic markers for the extinction learning of drug-associated cues.
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Affiliation(s)
- Freddyson J Martínez-Rivera
- Department of Anatomy and Neurobiology, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936, USA
| | - Namyr A Martínez
- Department of Physiology and Biophysics, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936, USA; Molecular Sciences Building, University of Puerto Rico, San Juan, PR 00926, USA
| | - Magdiel Martínez
- Department of Physiology and Biophysics, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936, USA; Molecular Sciences Building, University of Puerto Rico, San Juan, PR 00926, USA
| | - Roxsana N Ayala-Pagán
- Department of Anatomy and Neurobiology, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936, USA
| | - Walter I Silva
- Department of Physiology and Biophysics, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936, USA; Molecular Sciences Building, University of Puerto Rico, San Juan, PR 00926, USA
| | - Jennifer L Barreto-Estrada
- Department of Anatomy and Neurobiology, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936, USA.
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DosSantos MF, Moura BDS, DaSilva AF. Reward Circuitry Plasticity in Pain Perception and Modulation. Front Pharmacol 2017; 8:790. [PMID: 29209204 PMCID: PMC5702349 DOI: 10.3389/fphar.2017.00790] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 10/19/2017] [Indexed: 12/30/2022] Open
Abstract
Although pain is a widely known phenomenon and an important clinical symptom that occurs in numerous diseases, its mechanisms are still barely understood. Owing to the scarce information concerning its pathophysiology, particularly what is involved in the transition from an acute state to a chronic condition, pain treatment is frequently unsatisfactory, therefore contributing to the amplification of the chronic pain burden. In fact, pain is an extremely complex experience that demands the recruitment of an intricate set of central nervous system components. This includes cortical and subcortical areas involved in interpretation of the general characteristics of noxious stimuli. It also comprises neural circuits that process the motivational-affective dimension of pain. Hence, the reward circuitry represents a vital element for pain experience and modulation. This review article focuses on the interpretation of the extensive data available connecting the major components of the reward circuitry to pain suffering, including the nucleus accumbens, ventral tegmental area, and the medial prefrontal cortex; with especial attention dedicated to the evaluation of neuroplastic changes affecting these structures found in chronic pain syndromes, such as migraine, trigeminal neuropathic pain, chronic back pain, and fibromyalgia.
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Affiliation(s)
- Marcos F. DosSantos
- Laboratório de Morfogênese Celular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Brenda de Souza Moura
- Programa de Pós-Graduação em Radiologia, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alexandre F. DaSilva
- Headache and Orofacial Pain Effort, Department of Biologic and Materials Sciences, School of Dentistry, Center for Human Growth and Development, Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, United States
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Dias VT, Vey LT, Rosa HZ, D'avila LF, Barcelos RCS, Burger ME. Could Modafinil Prevent Psychostimulant Addiction? An Experimental Study in Rats. Basic Clin Pharmacol Toxicol 2017; 121:400-408. [DOI: 10.1111/bcpt.12821] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 05/23/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Verônica Tironi Dias
- Graduate Program of Pharmacology; Federal University of Santa Maria (UFSM) - RS; Santa Maria Brazil
| | - Luciana Taschetto Vey
- Graduate Program in Biological Sciences: Toxicological Biochemistry; Federal University of Santa Maria (UFSM) - RS; Santa Maria Brazil
| | - Higor Zuquetto Rosa
- Department of Physiology and Pharmacology; Federal University of Santa Maria (UFSM) - RS; Santa Maria Brazil
| | - Lívia Ferraz D'avila
- Graduate Program of Pharmacology; Federal University of Santa Maria (UFSM) - RS; Santa Maria Brazil
| | | | - Marilise Escobar Burger
- Graduate Program of Pharmacology; Federal University of Santa Maria (UFSM) - RS; Santa Maria Brazil
- Graduate Program in Biological Sciences: Toxicological Biochemistry; Federal University of Santa Maria (UFSM) - RS; Santa Maria Brazil
- Department of Physiology and Pharmacology; Federal University of Santa Maria (UFSM) - RS; Santa Maria Brazil
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Struik D, Fadda P, Zara T, Zamberletti E, Rubino T, Parolaro D, Fratta W, Fattore L. The anabolic steroid nandrolone alters cannabinoid self-administration and brain CB 1 receptor density and function. Pharmacol Res 2016; 115:209-217. [PMID: 27890818 DOI: 10.1016/j.phrs.2016.11.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 10/21/2016] [Accepted: 11/22/2016] [Indexed: 11/27/2022]
Abstract
Clinical and pre-clinical observations indicate that anabolic-androgenic steroids can induce neurobiological changes that alter the rewarding effects of drugs of abuse. In this study, we investigated the effect of the anabolic steroid nandrolone on the rewarding properties of the cannabinoid CB1 receptor agonist WIN55,212-2 (WIN) in rats. Lister Hooded male rats were treated intramuscularly with nandrolone (15mg/kg) or vehicle for 14 consecutive days, and then allowed to self-administer WIN (12.5μg/kg/infusion) intravenously. After reaching stable drug intake, self-administration behavior was extinguished to examine drug- and cue-induced reinstatement of cannabinoid-seeking behavior. Other behavioral parameters presumed to influence drug-taking and drug-seeking behaviors were examined to gain more insight into the behavioral specificity of nandrolone treatment. Finally, animals were sacrificed for analysis of CB1 receptor density and function in selected brain areas. We found that nandrolone-treated rats self-administered up to 2 times more cannabinoid than vehicle-treated rats, but behaved similarly to control rats when tested for drug- and cue-induced reinstatement of cannabinoid-seeking behavior. Enhanced cannabinoid intake by nandrolone-treated rats was not accompanied by changes in locomotor activity, sensorimotor gating, or memory function. However, our molecular data show that after chronic WIN self-administration nandrolone-treated rats display altered CB1 receptor density and function in selected brain areas. We hypothesize that increased cannabinoid self-administration in nandrolone-treated rats results from a nandrolone-induced decrease in reward function, which rats seem to compensate by voluntarily increasing their cannabinoid intake. Altogether, our findings corroborate the hypothesis that chronic exposure to anabolic-androgenic steroids induces dysfunction of the reward pathway in rats and might represent a potential risk factor for abuse of cannabis and other drugs in humans.
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Affiliation(s)
- Dicky Struik
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands
| | - Paola Fadda
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, SS 554Km 4,500, 09042 Monserrato, CA, Italy; Centre of Excellence "Neurobiology of Dependence", University of Cagliari, Cittadella Universitaria di Monserrato, SS 554 Km 4,500, 09042 Monserrato, CA, Italy
| | - Tamara Zara
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, SS 554Km 4,500, 09042 Monserrato, CA, Italy
| | - Erica Zamberletti
- Department of Biotechnology and Life Sciences, and Neuroscience Center University of Insubria, Busto Arsizio, VA, Italy
| | - Tiziana Rubino
- Department of Biotechnology and Life Sciences, and Neuroscience Center University of Insubria, Busto Arsizio, VA, Italy
| | - Daniela Parolaro
- Department of Biotechnology and Life Sciences, and Neuroscience Center University of Insubria, Busto Arsizio, VA, Italy; Zardi Gori Foundation, Via Curtatone 25, Milano, Italy
| | - Walter Fratta
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, SS 554Km 4,500, 09042 Monserrato, CA, Italy; Centre of Excellence "Neurobiology of Dependence", University of Cagliari, Cittadella Universitaria di Monserrato, SS 554 Km 4,500, 09042 Monserrato, CA, Italy
| | - Liana Fattore
- Centre of Excellence "Neurobiology of Dependence", University of Cagliari, Cittadella Universitaria di Monserrato, SS 554 Km 4,500, 09042 Monserrato, CA, Italy; CNR Institute of Neuroscience-Cagliari, National Research Council, Italy.
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Martínez-Rivera FJ, Rodriguez-Romaguera J, Lloret-Torres ME, Do Monte FH, Quirk GJ, Barreto-Estrada JL. Bidirectional Modulation of Extinction of Drug Seeking by Deep Brain Stimulation of the Ventral Striatum. Biol Psychiatry 2016; 80:682-690. [PMID: 27449798 PMCID: PMC5507549 DOI: 10.1016/j.biopsych.2016.05.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 05/03/2016] [Accepted: 05/24/2016] [Indexed: 01/02/2023]
Abstract
BACKGROUND Recent research in humans and rodents has explored the use of deep brain stimulation (DBS) of the ventral capsule/ventral striatum (VS) as a possible treatment for drug addiction. However, the optimum electrode placement and optimum DBS parameters have not been thoroughly studied. Here we varied stimulation sites and frequencies to determine whether DBS of the VS could facilitate the extinction of morphine-induced conditioned place preference in rats. METHODS Rats were implanted with DBS electrodes in the dorsal or ventral subregions of the VS and trained to the morphine conditioned place preference. Subsequently, rats received extinction sessions over 9 days, combined with 60 min of either high- (130 Hz) or low- (20 Hz) frequency DBS. To study circuit-wide activations after DBS of the VS, c-fos immunohistochemistry was performed in regions involved in the extinction of drug-seeking behaviors. RESULTS High-frequency DBS of the dorsal-VS impaired both extinction training and extinction memory, whereas high-frequency DBS of the ventral-VS had no effect. In contrast, low-frequency DBS of the dorsal-VS strengthened extinction memory when tested 2 or 9 days after the cessation of stimulation. Both DBS frequencies increased c-fos expression in the infralimbic prefrontal cortex, but only low-frequency DBS increased c-fos expression in the basal amygdala and the medial portion of the central amygdala. CONCLUSIONS Our results suggest that low-frequency (rather than high-frequency) DBS of the dorsal-VS strengthens extinction memory and may be a potential adjunct for extinction-based therapies for treatment-refractory opioid addiction.
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Affiliation(s)
| | - Jose Rodriguez-Romaguera
- Department of Psychiatry, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico
| | | | - Fabricio H Do Monte
- Department of Psychiatry, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico
| | - Gregory J Quirk
- Department of Anatomy and Neurobiology, San Juan, Puerto Rico; Department of Psychiatry, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico
| | - Jennifer L Barreto-Estrada
- Department of Anatomy and Neurobiology, San Juan, Puerto Rico; Department of Psychiatry, School of Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico.
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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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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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