1
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Zald DH. The influence of dopamine autoreceptors on temperament and addiction risk. Neurosci Biobehav Rev 2023; 155:105456. [PMID: 37926241 PMCID: PMC11330662 DOI: 10.1016/j.neubiorev.2023.105456] [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: 07/31/2023] [Revised: 10/22/2023] [Accepted: 10/31/2023] [Indexed: 11/07/2023]
Abstract
As a major regulator of dopamine (DA), DA autoreceptors (DAARs) exert substantial influence over DA-mediated behaviors. This paper reviews the physiological and behavioral impact of DAARs. Individual differences in DAAR functioning influences temperamental traits such as novelty responsivity and impulsivity, both of which are associated with vulnerability to addictive behavior in animal models and a broad array of externalizing behaviors in humans. DAARs additionally impact the response to psychostimulants and other drugs of abuse. Human PET studies of D2-like receptors in the midbrain provide evidence for parallels to the animal literature. These data lead to the proposal that weak DAAR regulation is a risk factor for addiction and externalizing problems. The review highlights the potential to build translational models of the functional role of DAARs in behavior. It also draws attention to key limitations in the current literature that would need to be addressed to further advance a weak DAAR regulation model of addiction and externalizing risk.
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Affiliation(s)
- David H Zald
- Center for Advanced Human Brain Imaging and Department of Psychiatry, Rutgers University, Piscataway, NJ, USA.
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2
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Yuen J, Goyal A, Rusheen AE, Kouzani AZ, Berk M, Kim JH, Tye SJ, Blaha CD, Bennet KE, Lee KH, Shin H, Oh Y. High frequency deep brain stimulation can mitigate the acute effects of cocaine administration on tonic dopamine levels in the rat nucleus accumbens. Front Neurosci 2023; 17:1061578. [PMID: 36793536 PMCID: PMC9922701 DOI: 10.3389/fnins.2023.1061578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 01/09/2023] [Indexed: 01/31/2023] Open
Abstract
Cocaine's addictive properties stem from its capacity to increase tonic extracellular dopamine levels in the nucleus accumbens (NAc). The ventral tegmental area (VTA) is a principal source of NAc dopamine. To investigate how high frequency stimulation (HFS) of the rodent VTA or nucleus accumbens core (NAcc) modulates the acute effects of cocaine administration on NAcc tonic dopamine levels multiple-cyclic square wave voltammetry (M-CSWV) was used. VTA HFS alone decreased NAcc tonic dopamine levels by 42%. NAcc HFS alone resulted in an initial decrease in tonic dopamine levels followed by a return to baseline. VTA or NAcc HFS following cocaine administration prevented the cocaine-induced increase in NAcc tonic dopamine. The present results suggest a possible underlying mechanism of NAc deep brain stimulation (DBS) in the treatment of substance use disorders (SUDs) and the possibility of treating SUD by abolishing dopamine release elicited by cocaine and other drugs of abuse by DBS in VTA, although further studies with chronic addiction models are required to confirm that. Furthermore, we demonstrated the use of M-CSWV can reliably measure tonic dopamine levels in vivo with both drug administration and DBS with minimal artifacts.
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Affiliation(s)
- Jason Yuen
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
- The Institute for Mental and Physical Health and Clinical Translation (IMPACT), Barwon Health, Deakin University, Geelong, VIC, Australia
| | - Abhinav Goyal
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
- Medical Scientist Training Program, Mayo Clinic, Rochester, MN, United States
| | - Aaron E. Rusheen
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
- Medical Scientist Training Program, Mayo Clinic, Rochester, MN, United States
| | - Abbas Z. Kouzani
- School of Engineering, Deakin University, Geelong, VIC, Australia
| | - Michael Berk
- The Institute for Mental and Physical Health and Clinical Translation (IMPACT), Barwon Health, Deakin University, Geelong, VIC, Australia
| | - Jee Hyun Kim
- The Institute for Mental and Physical Health and Clinical Translation (IMPACT), Barwon Health, Deakin University, Geelong, VIC, Australia
| | - Susannah J. Tye
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia
| | - Charles D. Blaha
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
| | - Kevin E. Bennet
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
- Division of Engineering, Mayo Clinic, Rochester, MN, United States
| | - Kendall H. Lee
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
| | - Hojin Shin
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
| | - Yoonbae Oh
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
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3
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McWain MA, Pace RL, Nalan PA, Lester DB. Age-dependent effects of social isolation on mesolimbic dopamine release. Exp Brain Res 2022; 240:2803-2815. [PMID: 36057752 PMCID: PMC9440747 DOI: 10.1007/s00221-022-06449-w] [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: 04/22/2022] [Accepted: 08/21/2022] [Indexed: 12/02/2022]
Abstract
In humans, social isolation is a known risk factor for disorders such as substance use disorder and depression. In rodents, social isolation is a commonly used environmental manipulation that increases the occurrence of behaviors related to these disorders. Age is thought to influence the effects of social isolation, but this predictive relationship is not well-understood. The present study aimed to determine the effects of social isolation on mesolimbic dopamine release at different developmental age points in mice. The experimental ages and their corresponding comparison to human age stages are as follows: 1 month = adolescence, 4 months = mature adulthood, 12 months = middle adulthood, and 18 months = older adult. Mice were socially isolated for 6 weeks during these developmental stages, then in vivo fixed potential amperometry with recording electrodes in the nucleus accumbens was used to measure stimulation-evoked dopamine release, the synaptic half-life of dopamine, dopamine autoreceptor functioning, and the dopaminergic response to cocaine. Isolation altered dopamine functioning in an age-dependent manner. Specifically, isolation increased dopamine release in the adult ages, but not adolescence, potentially due to increased inhibitory effects of dopamine autoreceptors following adolescent social isolation. Regarding the cocaine challenge, isolation increased dopaminergic responses to cocaine in adolescent mice, but not the adult mice. These findings have implications for clinical and experimental settings. Elucidating the relationship between age, social isolation, and neurochemical changes associated with substance use disorder and depression may lead to improvements in preventing and treating these disorders.
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Affiliation(s)
- Megan A McWain
- Department of Psychology, The University of Memphis, Memphis, TN, 38152-6400, USA
| | - Rachel L Pace
- Department of Psychology, The University of Memphis, Memphis, TN, 38152-6400, USA
| | - Patricia A Nalan
- Department of Psychology, The University of Memphis, Memphis, TN, 38152-6400, USA
| | - Deranda B Lester
- Department of Psychology, The University of Memphis, Memphis, TN, 38152-6400, USA.
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4
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Sex-specific effects of developmental exposure to polychlorinated biphenyls on neuroimmune and dopaminergic endpoints in adolescent rats. Neurotoxicol Teratol 2020; 79:106880. [PMID: 32259577 DOI: 10.1016/j.ntt.2020.106880] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/17/2020] [Accepted: 03/24/2020] [Indexed: 12/22/2022]
Abstract
Exposure to environmental contaminants early in life can have long lasting consequences for physiological function. Polychlorinated biphenyls (PCBs) are a group of ubiquitous contaminants that perturb endocrine signaling and have been associated with altered immune function in children. In this study, we examined the effects of developmental exposure to PCBs on neuroimmune responses to an inflammatory challenge during adolescence. Sprague Dawley rat dams were exposed to a PCB mixture (Aroclor 1242, 1248, 1254, 1:1:1, 20 μg/kg/day) or oil control throughout pregnancy, and adolescent male and female offspring were injected with lipopolysaccharide (LPS, 50 μg/kg, ip) or saline control prior to euthanasia. Gene expression profiling was conducted in the hypothalamus, prefrontal cortex, striatum, and midbrain. In the hypothalamus, PCBs increased expression of genes involved in neuroimmune function, including those within the nuclear factor kappa b (NF-κB) complex, independent of LPS challenge. PCB exposure also increased expression of receptors for dopamine, serotonin, and estrogen in this region. In contrast, in the prefrontal cortex, PCB exposure blunted or induced irregular neuroimmune gene expression responses to LPS challenge. Moreover, neither PCB nor LPS exposure altered expression of neurotransmitter receptors throughout the mesocorticolimbic circuit. Almost all effects were present in males but not females, in agreement with the idea that male neuroimmune cells are more sensitive to perturbation and emphasizing the importance of studying both male and female subjects. Given that altered neuroimmune signaling has been implicated in mental health and substance abuse disorders that often begin during adolescence, these results highlight neuroimmune processes as another mechanism by which early life PCBs can alter brain function later in life.
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5
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Freels TG, Gabriel DBK, Lester DB, Simon NW. Risky decision-making predicts dopamine release dynamics in nucleus accumbens shell. Neuropsychopharmacology 2020; 45:266-275. [PMID: 31546248 PMCID: PMC6901435 DOI: 10.1038/s41386-019-0527-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/06/2019] [Accepted: 09/12/2019] [Indexed: 01/07/2023]
Abstract
The risky decision-making task (RDT) measures risk-taking in a rat model by assessing preference between a small, safe reward and a large reward with increasing risk of punishment (mild foot shock). It is well-established that dopaminergic drugs modulate risk-taking; however, little is known about how differences in baseline phasic dopamine signaling drive individual differences in risk preference. Here, we used in vivo fixed potential amperometry in male Long-Evans rats to test if phasic nucleus accumbens shell (NACs) dopamine dynamics are associated with risk-taking. We observed a positive correlation between medial forebrain bundle-evoked dopamine release in the NACs and risky decision-making, suggesting that risk-taking is associated with elevated dopamine sensitivity. Moreover, "risk-taking" subjects were found to demonstrate greater phasic dopamine release than "risk-averse" subjects. Risky decision-making also predicted enhanced sensitivity to the dopamine reuptake inhibitor nomifensine, and elevated autoreceptor function. Importantly, this hyperdopaminergic phenotype was selective for risky decision-making, as delay discounting performance was not predictive of phasic dopamine release or dopamine supply. These data identify phasic NACs dopamine release as a possible therapeutic target for alleviating the excessive risk-taking observed across multiple forms of psychopathology.
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Affiliation(s)
- Timothy G. Freels
- 0000 0000 9560 654Xgrid.56061.34Department of Psychology, The University of Memphis, Memphis, TN 38152 USA
| | - Daniel B. K. Gabriel
- 0000 0000 9560 654Xgrid.56061.34Department of Psychology, The University of Memphis, Memphis, TN 38152 USA
| | - Deranda B. Lester
- 0000 0000 9560 654Xgrid.56061.34Department of Psychology, The University of Memphis, Memphis, TN 38152 USA
| | - Nicholas W. Simon
- 0000 0000 9560 654Xgrid.56061.34Department of Psychology, The University of Memphis, Memphis, TN 38152 USA
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6
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Freels TG, Lester DB, Cook MN. Arachidonoyl serotonin (AA-5-HT) modulates general fear-like behavior and inhibits mesolimbic dopamine release. Behav Brain Res 2019; 362:140-151. [DOI: 10.1016/j.bbr.2019.01.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 01/08/2019] [Accepted: 01/08/2019] [Indexed: 01/02/2023]
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7
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Hufgard JR, Sprowles JLN, Pitzer EM, Koch SE, Jiang M, Wang Q, Zhang X, Biesiada J, Rubinstein J, Puga A, Williams MT, Vorhees CV. Prenatal exposure to PCBs in Cyp1a2 knock-out mice interferes with F 1 fertility, impairs long-term potentiation, reduces acoustic startle and impairs conditioned freezing contextual memory with minimal transgenerational effects. J Appl Toxicol 2018; 39:603-621. [PMID: 30561030 DOI: 10.1002/jat.3751] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 09/17/2018] [Accepted: 10/14/2018] [Indexed: 01/17/2023]
Abstract
Polychlorinated biphenyls (PCBs) are toxic environmental pollutants. Humans are exposed to PCB mixtures via contaminated food or water. PCB exposure causes adverse effects in adults and after exposure in utero. PCB toxicity depends on the congener mixture and CYP1A2 gene activity. For coplanar PCBs, toxicity depends on ligand affinity for the aryl hydrocarbon receptor (AHR). Previously, we found that perinatal exposure of mice to a three-coplanar/five-noncoplanar PCB mixture induced deficits in novel object recognition and trial failures in the Morris water maze in Cyp1a2-/- ::Ahrb1 C57BL6/J mice compared with wild-type mice (Ahrb1 = high AHR affinity). Here we exposed gravid Cyp1a2-/- ::Ahrb1 mice to a PCB mixture on embryonic day 10.5 by gavage and examined the F1 and F3 offspring (not F2 ). PCB-exposed F1 mice exhibited increased open-field central time, reduced acoustic startle, greater conditioned contextual freezing and reduced CA1 hippocampal long-term potentiation with no change in spatial learning or memory. F1 mice also had inhibited growth, decreased heart rate and cardiac output, and impaired fertility. F3 mice showed few effects. Gene expression changes were primarily in F1 PCB males compared with wild-type males. There were minimal RNA and DNA methylation changes in the hippocampus from F1 to F3 with no clear relevance to the functional effects. F0 PCB exposure during a period of rapid DNA de-/remethylation in a susceptible genotype produced clear F1 effects with little evidence of transgenerational effects in the F3 generation. While PCBs show clear developmental neurotoxicity, their effects do not persist across generations for effects assessed herein.
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Affiliation(s)
- Jillian R Hufgard
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA
| | - Jenna L N Sprowles
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA
| | - Emily M Pitzer
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA
| | - Sheryl E Koch
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Min Jiang
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Qin Wang
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Xiang Zhang
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Jacek Biesiada
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Jack Rubinstein
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Alvaro Puga
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Michael T Williams
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA
| | - Charles V Vorhees
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA
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8
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Holloway ZR, Freels TG, Comstock JF, Nolen HG, Sable HJ, Lester DB. Comparing phasic dopamine dynamics in the striatum, nucleus accumbens, amygdala, and medial prefrontal cortex. Synapse 2018; 73:e22074. [PMID: 30317673 DOI: 10.1002/syn.22074] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/14/2018] [Accepted: 10/10/2018] [Indexed: 01/05/2023]
Abstract
Midbrain dopaminergic neurons project to and modulate multiple highly interconnected modules of the basal ganglia, limbic system, and frontal cortex. Dopamine regulates behaviors associated with action selection in the striatum, reward in the nucleus accumbens (NAc), emotional processing in the amygdala, and executive functioning in the medial prefrontal cortex (mPFC). The multifunctionality of dopamine likely occurs at the individual synapses, with varied levels of phasic dopamine release acting on different receptor populations. This study aimed to characterize specific aspects of stimulation-evoked phasic dopamine transmission, beyond simple dopamine release, using in vivo fixed potential amperometry with carbon fiber recording microelectrodes positioned in either the dorsal striatum, NAc, amygdala, or mPFC of anesthetized mice. To summarize results, the present study found that the striatum and NAc had increased stimulation-evoked phasic dopamine release, faster dopamine uptake (leading to restricted dopamine diffusion), weaker autoreceptor functioning, greater supply levels of available dopamine, and increased dopaminergic responses to DAT blockade compared to the amygdala and mPFC. Overall, these findings indicate that phasic dopamine may have different modes of communication between striatal and corticolimbic regions, with the first being profuse in concentration, rapid, and synaptically confined and the second being more limited in concentration but longer lasting and spatially dispersed. An improved understanding of regional differences in dopamine transmission can lead to more efficient treatments for disorders related to dopamine dysfunction.
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Affiliation(s)
- Zade R Holloway
- Department of Psychology, University of Memphis, Memphis, Tennessee
| | - Timothy G Freels
- Department of Psychology, University of Memphis, Memphis, Tennessee
| | | | - Hunter G Nolen
- Department of Psychology, University of Memphis, Memphis, Tennessee
| | - Helen J Sable
- Department of Psychology, University of Memphis, Memphis, Tennessee
| | - Deranda B Lester
- Department of Psychology, University of Memphis, Memphis, Tennessee
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9
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Prater WT, Swamy M, Beane MD, Lester DB. Examining the Effects of Common Laboratory Methods on the Sensitivity of Carbon Fiber Electrodes in Amperometric Recordings of Dopamine. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/jbbs.2018.83007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Miller MM, Sprowles JLN, Voeller JN, Meyer AE, Sable HJK. Cocaine sensitization in adult Long-Evans rats perinatally exposed to polychlorinated biphenyls. Neurotoxicol Teratol 2017; 62:34-41. [PMID: 28465083 DOI: 10.1016/j.ntt.2017.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/20/2017] [Accepted: 04/25/2017] [Indexed: 11/15/2022]
Abstract
Polychlorinated biphenyls (PCBs) are ubiquitous environmental toxicants known to adversely affect the nervous system and more specifically the dopamine system. Developmental PCB exposure in rats has been shown to produce alterations in dopaminergic signaling that persist into adulthood. The reinforcing properties of psychostimulants are typically modulated via the dopaminergic system, so this project used a behavioral sensitization paradigm to evaluate whether perinatal PCB exposure altered sensitization to the psychostimulant cocaine. Long-Evans rats were perinatally exposed to 0, 3 or 6mg/kg/day of PCBs throughout gestation and lactation. One male and female pup from each litter was retained for behavioral testing. Both horizontal and vertical activity were used to measure cocaine sensitization following repeated injections of 10mg/kg cocaine (IP) on post-natal day (PND) 91-96 and again after a week in the home cage on PND 103. A final locomotor activity session following a challenge injection of 20mg/kg was given on PND 110 to further evaluate the availability of presynaptic dopamine stores. The PCB-exposed rats appeared to be pre-sensitized to cocaine as they exhibited a greater degree of cocaine-induced locomotor activation to the initial injections of cocaine and therefore demonstrated a more rapid onset of cocaine behavioral sensitization compared to non-exposed controls. These results add to the literature detailing how perinatal exposure to dopamine-disrupting contaminants can change the developing brain, thereby producing permanent changes in the neurobehavioral response to psychostimulants later in life.
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Affiliation(s)
- Mellessa M Miller
- Department of Psychology, University of Memphis, Memphis, TN 38152, USA
| | - Jenna L N Sprowles
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Jason N Voeller
- Department of Psychology, University of Memphis, Memphis, TN 38152, USA
| | - Abby E Meyer
- Department of Psychological Science, University of North, Georgia, Dahlonega, GA 30597
| | - Helen J K Sable
- Department of Psychology, University of Memphis, Memphis, TN 38152, USA.
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11
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Miller MM, Meyer AE, Sprowles JLN, Sable HJK. Cocaine self-administration in male and female rats perinatally exposed to PCBs: Evaluating drug use in an animal model of environmental contaminant exposure. Exp Clin Psychopharmacol 2017; 25:114-124. [PMID: 28287790 PMCID: PMC5367977 DOI: 10.1037/pha0000113] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Polychlorinated biphenyls (PCBs) are ubiquitous environmental toxicants known to adversely impact human health. Ortho-substituted PCBs affect the nervous system, including the brain dopaminergic system. The reinforcing effects of psychostimulants are typically modulated via the dopaminergic system, so this study used a preclinical (i.e., rodent) model to evaluate whether developmental contaminant exposure altered intravenous self-administration (IV SA) for the psychostimulant cocaine. Long-Evans rats were perinatally exposed to 6 or 3 mg/kg/day of PCBs throughout gestation and lactation and compared with nonexposed controls. Rats were trained to lever press for a food reinforcer in an operant chamber under a fixed-ratio 5 (FR5) schedule and later underwent jugular catheterization. Food reinforcers were switched for infusions of 250 μg of cocaine, but the response requirement to earn the reinforcer remained. Active lever presses and infusions were higher in males during response acquisition and maintenance. The same sex effect was observed during later sessions which evaluated responding for cocaine doses ranging from 31.25-500 μg. PCB-exposed males (not females) exhibited an increase in cocaine infusions (with a similar trend in active lever presses) during acquisition, but no PCB-related differences were observed during maintenance, examination of the cocaine dose-response relationship, or progressive ratio (PR) sessions. Overall, these results indicated perinatal PCB exposure enhanced early cocaine drug-seeking in this preclinical model of developmental contaminant exposure (particularly the males), but no differences were seen during later cocaine SA sessions. As such, additional questions regarding substance abuse proclivity may be warranted in epidemiological studies evaluating environmental contaminant exposures. (PsycINFO Database Record
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Affiliation(s)
| | - Abby E. Meyer
- Department of Psychological Science, University of North Georgia, Dahlonega, GA 30597
| | - Jenna L. N. Sprowles
- Division of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Helen J. K. Sable
- Department of Psychology, University of Memphis, Memphis, TN 38152
- Corresponding author: Helen J. K. Sable, Ph.D., University of Memphis, Department of Psychology, 400 Innovation Drive, 202 Psychology Building, Memphis, TN 38152, USA, Tel: +1-901-678-4343, Fax: +1-901-678-2579,
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12
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Bell MR, Hart BG, Gore AC. Two-hit exposure to polychlorinated biphenyls at gestational and juvenile life stages: 2. Sex-specific neuromolecular effects in the brain. Mol Cell Endocrinol 2016; 420:125-37. [PMID: 26620572 PMCID: PMC4703537 DOI: 10.1016/j.mce.2015.11.024] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 11/20/2015] [Accepted: 11/21/2015] [Indexed: 10/22/2022]
Abstract
Exposures to polychlorinated biphenyls (PCBs) during early development have long-lasting, sexually dimorphic consequences on adult brain and behavior. However, few studies have investigated their effects during juvenile development, a time when increases in pubertal hormones influence brain maturation. Here, male and female Sprague Dawley rats were exposed to PCBs (Aroclor 1221, 1 mg/kg/day) or vehicle prenatally, during juvenile development, or both, and their effects on serum hormone concentrations, gene expression, and DNA methylation were assessed in adulthood. Gene expression in male but not female brains was affected by 2-hits of PCBs, a result that paralleled behavioral effects of PCBs. Furthermore, the second hit often changed the effects of a first hit in complex ways. Thus, PCB exposures during critical fetal and juvenile developmental periods result in unique neuromolecular phenotypes, with males most vulnerable to the treatments.
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Affiliation(s)
- Margaret R Bell
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA
| | - Bethany G Hart
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA
| | - Andrea C Gore
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA; Institute for Neuroscience, The University of Texas at Austin, Austin, TX 78712, USA.
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13
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Endocrine-disrupting actions of PCBs on brain development and social and reproductive behaviors. Curr Opin Pharmacol 2014; 19:134-44. [PMID: 25310366 DOI: 10.1016/j.coph.2014.09.020] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 09/24/2014] [Accepted: 09/24/2014] [Indexed: 11/20/2022]
Abstract
Polychlorinated biphenyls are among the most well-studied endocrine-disrupting chemicals (EDCs) for their neurobehavioral effects, especially neurodevelopment and cognitive performance. In addition, past research has demonstrated effects of PCBs on circulating hormones and associated changes in reproductive behaviors. This article will focus on recent advances that have been made in characterizing developmental PCB effects on reproductive function, broader social and affective behaviors, and the neuroendocrine mechanisms behind such changes. In general, PCBs seem to inhibit reproductive function by suppressing multiple aspects of the associated hypothalamic circuitry. Additionally, PCBs may also reduce motivation for social behaviors and induce depressive-like symptoms via overall reductions in dopaminergic and glutamatergic functions in the limbic system. However, more work with human-relevant exposure paradigms is needed to fully support these conclusions.
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León-Olea M, Martyniuk CJ, Orlando EF, Ottinger MA, Rosenfeld C, Wolstenholme J, Trudeau VL. Current concepts in neuroendocrine disruption. Gen Comp Endocrinol 2014; 203:158-173. [PMID: 24530523 PMCID: PMC4133337 DOI: 10.1016/j.ygcen.2014.02.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 02/01/2014] [Accepted: 02/04/2014] [Indexed: 11/17/2022]
Abstract
In the last few years, it has become clear that a wide variety of environmental contaminants have specific effects on neuroendocrine systems in fish, amphibians, birds and mammals. While it is beyond the scope of this review to provide a comprehensive examination of all of these neuroendocrine disruptors, we will focus on select representative examples. Organochlorine pesticides bioaccumulate in neuroendocrine areas of the brain that directly regulate GnRH neurons, thereby altering the expression of genes downstream of GnRH signaling. Organochlorine pesticides can also agonize or antagonize hormone receptors, adversely affecting crosstalk between neurotransmitter systems. The impacts of polychlorinated biphenyls are varied and in many cases subtle. This is particularly true for neuroedocrine and behavioral effects of exposure. These effects impact sexual differentiation of the hypothalamic-pituitary-gonadal axis, and other neuroendocrine systems regulating the thyroid, metabolic, and stress axes and their physiological responses. Weakly estrogenic and anti-androgenic pollutants such as bisphenol A, phthalates, phytochemicals, and the fungicide vinclozolin can lead to severe and widespread neuroendocrine disruptions in discrete brain regions, including the hippocampus, amygdala, and hypothalamus, resulting in behavioral changes in a wide range of species. Behavioral features that have been shown to be affected by one or more these chemicals include cognitive deficits, heightened anxiety or anxiety-like, sociosexual, locomotor, and appetitive behaviors. Neuroactive pharmaceuticals are now widely detected in aquatic environments and water supplies through the release of wastewater treatment plant effluents. The antidepressant fluoxetine is one such pharmaceutical neuroendocrine disruptor. Fluoxetine is a selective serotonin reuptake inhibitor that can affect multiple neuroendocrine pathways and behavioral circuits, including disruptive effects on reproduction and feeding in fish. There is growing evidence for the association between environmental contaminant exposures and diseases with strong neuroendocrine components, for example decreased fecundity, neurodegeneration, and cardiac disease. It is critical to consider the timing of exposures of neuroendocrine disruptors because embryonic stages of central nervous system development are exquisitely sensitive to adverse effects. There is also evidence for epigenetic and transgenerational neuroendocrine disrupting effects of some pollutants. We must now consider the impacts of neuroendocrine disruptors on reproduction, development, growth and behaviors, and the population consequences for evolutionary change in an increasingly contaminated world. This review examines the evidence to date that various so-called neuroendocrine disruptors can induce such effects often at environmentally-relevant concentrations.
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Affiliation(s)
- Martha León-Olea
- Departamento de Neuromorfología Funcional, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría, R.F.M., México D.F., México
| | - Christopher J. Martyniuk
- Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, New Brunswick, E2L 4L5, Canada
| | - Edward F. Orlando
- University of Maryland, Department of Animal and Avian Sciences, College Park, MD 20742, USA
| | - Mary Ann Ottinger
- University of Maryland, Department of Animal and Avian Sciences, College Park, MD 20742, USA
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204, USA
| | - Cheryl Rosenfeld
- Departments of Biomedical Sciences and Bond Life Sciences Center, Genetics Area Program, University of Missouri, Columbia, MO 65211, USA
| | - Jennifer Wolstenholme
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 23112, USA
| | - Vance L. Trudeau
- Department of Biology, University of Ottawa, 30 Marie Curie Private, Ottawa, ON, Canada, K1N 6N5
- Corresponding author:
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