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Martin MM, Graham DL, McCarthy DM, Bhide PG, Stanwood GD. Cocaine-induced neurodevelopmental deficits and underlying mechanisms. BIRTH DEFECTS RESEARCH. PART C, EMBRYO TODAY : REVIEWS 2016; 108:147-73. [PMID: 27345015 PMCID: PMC5538582 DOI: 10.1002/bdrc.21132] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 06/06/2016] [Indexed: 11/06/2022]
Abstract
Exposure to drugs early in life has complex and long-lasting implications for brain structure and function. This review summarizes work to date on the immediate and long-term effects of prenatal exposure to cocaine. In utero cocaine exposure produces disruptions in brain monoamines, particularly dopamine, during sensitive periods of brain development, and leads to permanent changes in specific brain circuits, molecules, and behavior. Here, we integrate clinical studies and significance with mechanistic preclinical studies, to define our current knowledge base and identify gaps for future investigation. Birth Defects Research (Part C) 108:147-173, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Melissa M. Martin
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, Florida
| | - Devon L. Graham
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, Florida
| | - Deirdre M. McCarthy
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, Florida
| | - Pradeep G. Bhide
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, Florida
| | - Gregg D. Stanwood
- Department of Biomedical Sciences and Center for Brain Repair, Florida State University College of Medicine, Tallahassee, Florida
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Williams SK, Lauder JM, Johns JM. Prenatal Cocaine Disrupts Serotonin Signaling-Dependent Behaviors: Implications for Sex Differences, Early Stress and Prenatal SSRI Exposure. Curr Neuropharmacol 2011; 9:478-511. [PMID: 22379462 PMCID: PMC3151602 DOI: 10.2174/157015911796557957] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 12/31/2010] [Accepted: 01/07/2011] [Indexed: 02/06/2023] Open
Abstract
Prenatal cocaine (PC) exposure negatively impacts the developing nervous system, including numerous changes in serotonergic signaling. Cocaine, a competitive antagonist of the serotonin transporter, similar to selective serotonin reuptake inhibitors (SSRIs), also blocks dopamine and norepinephrine transporters, leaving the direct mechanism through which cocaine disrupts the developing serotonin system unclear. In order to understand the role of the serotonin transporter in cocaine's effect on the serotonergic system, we compare reports concerning PC and prenatal antidepressant exposure and conclude that PC exposure affects many facets of serotonergic signaling (serotonin levels, receptors, transporters) and that these effects differ significantly from what is observed following prenatal SSRI exposure. Alterations in serotonergic signaling are dependent on timing of exposure, test regimens, and sex. Following PC exposure, behavioral disturbances are observed in attention, emotional behavior and stress response, aggression, social behavior, communication, and like changes in serotonergic signaling, these effects depend on sex, age and developmental exposure. Vulnerability to the effects of PC exposure can be mediated by several factors, including allelic variance in serotonergic signaling genes, being male (although fewer studies have investigated female offspring), and experiencing the adverse early environments that are commonly coincident with maternal drug use. Early environmental stress results in disruptions in serotonergic signaling analogous to those observed with PC exposure and these may interact to produce greater behavioral effects observed in children of drug-abusing mothers. We conclude that based on past evidence, future studies should put a greater emphasis on including females and monitoring environmental factors when studying the impact of PC exposure.
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Affiliation(s)
- Sarah K Williams
- Curriculum in Neurobiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jean M Lauder
- Curriculum in Neurobiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Josephine M Johns
- Curriculum in Neurobiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Psychology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Iñiguez SD, Warren BL, Bolaños-Guzmán CA. Short- and long-term functional consequences of fluoxetine exposure during adolescence in male rats. Biol Psychiatry 2010; 67:1057-66. [PMID: 20172503 PMCID: PMC2868075 DOI: 10.1016/j.biopsych.2009.12.033] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 12/18/2009] [Accepted: 12/22/2009] [Indexed: 12/15/2022]
Abstract
BACKGROUND Fluoxetine (FLX), a selective serotonin reuptake inhibitor, is prescribed for the treatment of major depressive disorder in young populations. Here, we explore the short- and long-term consequences of adolescent exposure to FLX on behavioral reactivity to emotion-eliciting stimuli. METHODS Adolescent male rats received FLX (10 mg/kg) twice daily for 15 consecutive days (postnatal days 35-49). The influence of FLX on behavioral reactivity to rewarding and aversive stimuli was assessed 24 hours (short-term) or 3 weeks after FLX treatment (long-term). A separate group of adult rats was also treated with FLX (postnatal days 65-79) and responsiveness to forced swimming was assessed at identical time intervals as with the adolescents. RESULTS Fluoxetine exposure during adolescence resulted in long-lasting decreases in behavioral reactivity to forced swimming stress and enhanced sensitivity to sucrose and to anxiety-eliciting situations in adulthood. The FLX-induced anxiety-like behavior was alleviated by re-exposure to FLX in adulthood. Fluoxetine treatment during adolescence also impaired sexual copulatory behaviors in adulthood. Fluoxetine-treated adult rats did not show changes in behavioral reactivity to forced swim stress as observed in those treated during adolescence and tested in adulthood. CONCLUSIONS Treating adolescent rats with FLX results in long-lived complex outputs regulated by the emotional valence of the stimulus, the environment in which it is experienced, and the brain circuitry likely being engaged by it. Our findings highlight the need for further research to improve our understanding of the alterations that psychotropic exposure may induce on the developing nervous system and the potential enduring effects resulting from such treatments.
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Affiliation(s)
- Sergio D Iñiguez
- Department of Psychology, Florida State University, Tallahassee, FL 32306-4301, USA
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Abstract
Central nervous system cholinergic neurons arise from several discrete sources, project to multiple brain regions, and exert specific effects on reward, learning, and memory. These processes are critical for the development and persistence of addictive disorders. Although other neurotransmitters, including dopamine, glutamate, and serotonin, have been the primary focus of drug research to date, a growing preclinical literature reveals a critical role of acetylcholine (ACh) in the experience and progression of drug use. This review will present and integrate the findings regarding the role of ACh in drug dependence, with a primary focus on cocaine and the muscarinic ACh system. Mesostriatal ACh appears to mediate reinforcement through its effect on reward, satiation, and aversion, and chronic cocaine administration produces neuroadaptive changes in the striatum. ACh is further involved in the acquisition of conditional associations that underlie cocaine self-administration and context-dependent sensitization, the acquisition of associations in conditioned learning, and drug procurement through its effects on arousal and attention. Long-term cocaine use may induce neuronal alterations in the brain that affect the ACh system and impair executive function, possibly contributing to the disruptions in decision making that characterize this population. These primarily preclinical studies suggest that ACh exerts a myriad of effects on the addictive process and that persistent changes to the ACh system following chronic drug use may exacerbate the risk of relapse during recovery. Ultimately, ACh modulation may be a potential target for pharmacological treatment interventions in cocaine-addicted subjects. However, the complicated neurocircuitry of the cholinergic system, the multiple ACh receptor subtypes, the confluence of excitatory and inhibitory ACh inputs, and the unique properties of the striatal cholinergic interneurons suggest that a precise target of cholinergic manipulation will be required to impact substance use in the clinical population.
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Affiliation(s)
- Mark J Williams
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390-8564, USA.
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Bolaños CA, Willey MD, Maffeo ML, Powers KD, Kinka DW, Grausam KB, Henderson RP. Antidepressant treatment can normalize adult behavioral deficits induced by early-life exposure to methylphenidate. Biol Psychiatry 2008; 63:309-16. [PMID: 17884021 DOI: 10.1016/j.biopsych.2007.06.024] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 06/01/2007] [Accepted: 06/23/2007] [Indexed: 01/26/2023]
Abstract
BACKGROUND Methylphenidate (MPH) is prescribed for the treatment of attention-deficit/hyperactivity disorder. Exposure to MPH before adulthood causes behavioral deficits later in life, including anxiety- and depression-like behaviors and decreased responding to natural and drug rewards. We examined the ability of fluoxetine (FLX), a selective serotonin reuptake blocker, to normalize these MPH-induced behavioral deficits. METHODS Male rats received MPH (2.0 mg/kg) or saline (VEH) during preadolescence (postnatal day [PD] 20-35). When adults, rats were divided into groups receiving no treatment, acute or chronic FLX, and behavioral reactivity to several emotion-eliciting stimuli were assessed. RESULTS The MPH-treated rats were significantly less responsive to natural (i.e., sucrose) and drug (i.e., morphine) rewards and more sensitive to stress- and anxiety-eliciting situations. These MPH-induced deficits were reversed by exposure to FLX. CONCLUSIONS These results indicate that exposure to MPH during preadolescence leads to behavioral alterations that endure into adulthood and that these behavioral deficits can be normalized by antidepressant treatment. These results highlight the need for further research to better understand the effects of stimulants on the developing nervous system and the potential enduring effects resulting from early-life drug exposure.
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Affiliation(s)
- Carlos A Bolaños
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306-4301, USA.
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Trksak GH, Glatt SJ, Mortazavi F, Jackson D. A meta-analysis of animal studies on disruption of spatial navigation by prenatal cocaine exposure. Neurotoxicol Teratol 2007; 29:570-7. [PMID: 17683902 PMCID: PMC2200866 DOI: 10.1016/j.ntt.2007.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Revised: 05/04/2007] [Accepted: 06/17/2007] [Indexed: 11/29/2022]
Abstract
Water-maze testing has been used to assess prenatal cocaine (PCOC)-induced deficits in behavioral studies of spatial navigation and memory abilities. Effects of PCOC in acquisition or in probe trials over water-maze testing days were rarely detected. Despite an absence of effects of PCOC when data were collapsed over multiple days, there was a potential difference when examined during the first day of acquisition training, characterized by a PCOC-associated decrease in learning efficiency but not capacity. Here, we review studies of PCOC-related changes in day-1 water-maze acquisition training and examine the relationship between experimental methodologies and PCOC-treatment procedures and the variability in effect size estimates across studies. The results revealed a significant increase in latencies to goal platform on acquisition training day-1 in PCOC-exposed offspring vs. controls (effect size: r=0.44). Significant effects attributable to variations in the PCOC-treatment procedures across studies were also identified. The moderating variable of PCOC "dose" was significant as lower doses of PCOC exposure yielded larger treatment effects. "Duration" of PCOC exposure was not significant, although a trend for greater effects was observed in studies that employed longer daily treatment schedules or schedules administered in later gestational periods. This analysis identified a consistent difference in acquisition training day-1 of water-maze testing in PCOC-exposed offspring indicating a PCOC-induced deficiency in spatial learning. These findings of impaired spatial learning efficiency are of particular interest given clinical scenarios involving acutely impaired spatial memory and related learning in PCOC-exposed children that highlight the potential consequences in classroom learning.
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Affiliation(s)
- George H Trksak
- Behavioral Pharmacology Research Laboratory, McLean Hospital, Harvard Medical School, 115 Mill Street, Belmont, MA 02478, USA.
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Booze RM, Wallace DR, Silvers JM, Strupp BJ, Snow DM, Mactutus CF. Prenatal cocaine exposure alters alpha2 receptor expression in adolescent rats. BMC Neurosci 2006; 7:33. [PMID: 16620392 PMCID: PMC1513240 DOI: 10.1186/1471-2202-7-33] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Accepted: 04/18/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Prenatal cocaine exposure produces attentional deficits which to persist through early childhood. Given the role of norepinephrine (NE) in attentional processes, we examined the forebrain NE systems from prenatal cocaine exposed rats. Cocaine was administered during pregnancy via the clinically relevant intravenous route of administration. Specifically, we measured alpha2-adrenergic receptor (alpha2-AR) density in adolescent (35-days-old) rats, using [3H]RX821002 (5 nM). RESULTS Sex-specific alterations of alpha2-AR were found in the hippocampus and amygdala of the cocaine-exposed animals, as well as an upregulation of alpha2-AR in parietal cortex. CONCLUSION These data suggest that prenatal cocaine exposure results in a persistent alteration in forebrain NE systems as indicated by alterations in receptor density. These neurochemical changes may underlie behavioral abnormalities observed in offspring attentional processes following prenatal exposure to cocaine.
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Affiliation(s)
- Rosemarie M Booze
- Department of Psychology, University of South Carolina Columbia, SC 29208, USA
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina Columbia, SC 29208, USA
| | - David R Wallace
- Department of Pharmacology and Physiology, Oklahoma State University, College of Osteopathic Medicine Tulsa, OK 74017-1898, USA
| | - Janelle M Silvers
- Department of Psychology, University of South Carolina Columbia, SC 29208, USA
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina Columbia, SC 29208, USA
| | - Barbara J Strupp
- Division of Nutritional Sciences and Department of Psychology, Cornell University Ithaca, NY 14853-6301, USA
| | - Diane M Snow
- Department of Anatomy and Neurobiology, The University of Kentucky, Lexington, KY 40536-0298, USA
| | - Charles F Mactutus
- Department of Psychology, University of South Carolina Columbia, SC 29208, USA
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Jackson D, Burns R, Trksak G, Simeone B, DeLeon KR, Connor DF, Harrison RJ, Melloni RH. Anterior hypothalamic vasopressin modulates the aggression-stimulating effects of adolescent cocaine exposure in Syrian hamsters. Neuroscience 2005; 133:635-46. [PMID: 15908133 DOI: 10.1016/j.neuroscience.2005.02.047] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Revised: 02/15/2005] [Accepted: 02/20/2005] [Indexed: 12/29/2022]
Abstract
Repeated low-dose cocaine treatment (0.5 mg/kg/day) during adolescence induces offensive aggression in male Syrian hamsters (Mesocricetus auratus). This study examines the hypothesis that adolescent cocaine exposure predisposes hamsters to heightened levels of aggressive behavior by increasing the activity of the anterior hypothalamic-vasopressinergic neural system. In a first experiment, adolescent male hamsters were treated with low-dose cocaine and then scored for offensive aggression in the absence or presence of vasopressin receptor antagonists applied directly to the anterior hypothalamus. Adolescent cocaine-treated hamsters displayed highly escalated offensive aggression that could be reversed by blocking the activity of vasopressin receptors within the anterior hypothalamus. In a second set of experiments, adolescent hamsters were administered low-dose cocaine or vehicle, tested for offensive aggression, and then examined for differences in vasopressin innervation patterns and expression levels in the anterior hypothalamus, as well as the basal- and stimulated-release of vasopressin in this same brain region. Aggressive, adolescent cocaine-treated hamsters showed no differences in vasopressin afferent innervation and/or peptide levels in the anterior hypothalamus compared with non-aggressive, saline-treated littermates. Conversely, significant increases in stimulated, but not basal, vasopressin release were detected from the anterior hypothalamus of aggressive, cocaine-treated animals compared with non-aggressive, saline-treated controls. Together, these data suggest that adolescent cocaine exposure increases aggression by increasing stimulated release of vasopressin in the anterior hypothalamus, providing direct evidence for a causal role of anterior hypothalamic-vasopressin activity in adolescent cocaine-induced offensive aggression. A model for how alterations in anterior hypothalamic-vasopressin neural functioning may facilitate the development of the aggressive phenotype in adolescent-cocaine exposed animals is presented.
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Affiliation(s)
- D Jackson
- Behavioral Neuroscience Program, Department of Psychology, 125 Nightingale Hall, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA
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Santucci AC, Capodilupo S, Bernstein J, Gomez-Ramirez M, Milefsky R, Mitchell H. Cocaine in adolescent rats produces residual memory impairments that are reversible with time. Neurotoxicol Teratol 2004; 26:651-61. [PMID: 15315814 DOI: 10.1016/j.ntt.2004.06.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2004] [Revised: 05/26/2004] [Accepted: 06/04/2004] [Indexed: 11/21/2022]
Abstract
Rats received injections (subcutaneous) of either 10 or 20 mg/kg cocaine on postnatal days 26-33, while lab chow-fed and pair-fed controls received saline. Spatial memory in a Morris water maze was assessed on four different occasions commencing 10 days postcocaine and ending approximately 12 months later. To determine whether there existed long-term changes in cholinergic processes, maze performance was evaluated following 1 mg/kg scopolamine challenge 4 months postcocaine. Subjects survived under standard laboratory housing conditions until they died. Results from the first assessment indicated a working memory deficit in the low-dose cocaine group and a long-term memory impairment in the high-dose cocaine group. These decrements neither were permanent nor were exacerbated by age-related processes in that cocaine-treated subjects performed at control levels on subsequent assessments. An exception to this was the results derived from the third assessment indicating that animals previously treated with 20 mg/kg cocaine were impaired when challenged with scopolamine. Examination of mortality rates revealed that cocaine-treated rats died significantly sooner than lab chow-fed control subjects. Taken together, these data indicate that cocaine during adolescence causes residual, but not permanent, deleterious effects on memory that may be mediated by alterations in cholinergic neurochemistry. More provocatively, the results showed that cocaine during adolescence shortened the lifespan of rats. This latter finding suggests that cocaine during adolescence may produce residual physiological effects that last well into adulthood.
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Affiliation(s)
- Anthony C Santucci
- Department of Psychology, Manhattanville College, 2900 Purchase Street, Purchase, NY 10577, USA.
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Glatt SJ, Trksak GH, Cohen OS, Simeone BP, Jackson D. Prenatal cocaine exposure decreases nigrostriatal dopamine release in vitro: Effects of age and sex. Synapse 2004; 53:74-89. [PMID: 15170820 DOI: 10.1002/syn.20036] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The present study examined the effects of prenatal cocaine (PCOC) exposure, age, sex, and estrous phase on the functional development of nigrostriatal dopamine (DA) neurons. Striatal tissue was obtained from prepubescent and adult rats of both sexes after bidaily exposure to saline (1 ml/kg) or cocaine (20 mg/kg/ml saline) from embryonic days 15-21. Tissue levels, basal release, and electrically evoked (1 or 8 Hz) overflow of endogenous DA and its metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), as well as their efflux in response to superfusion with the DA transport blocker, nomifensine (10 microM), were measured from superfused striatal slices. Generally, these measures were highest in tissue from males and adults. Tissue DA and DOPAC levels and the rate of DA turnover were unaffected by PCOC exposure. Slices from PCOC-exposed juvenile and adult male rats exhibited significantly reduced basal and electrically evoked DA release at both stimulation intensities, in conjunction with higher levels of presynaptic DA reuptake. Female rats were largely spared from the effects of PCOC exposure, and measures did not vary with estrous phase. These findings demonstrate that the effects of PCOC exposure on various parameters of nigrostriatal DA neuronal function are not uniform across age, sex, or phases of the estrous cycle. These novel alterations in nigrostriatal DA transmission are in need of independent replication, but they may have profound implications for behavioral activities regulated by these neurons and, thus, may provide a basis for sex-selective effects of PCOC in exposed humans. Possible mechanisms of deleterious effects of PCOC exposure in select groups are discussed.
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Affiliation(s)
- Stephen J Glatt
- Department of Psychology, Northeastern University, Boston, Massachusetts, USA.
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Bolaños CA, Trksak GH, Cohen OS, Jackson D. Differential serotonergic inhibition of in vitro striatal [3H]acetylcholine release in prenatally cocaine-exposed male and female rats. Prog Neuropsychopharmacol Biol Psychiatry 2002; 26:1339-48. [PMID: 12502023 DOI: 10.1016/s0278-5846(02)00299-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Previous research indicates that prenatal cocaine (pCOC)-exposure results in greater 5-HT3 agonist-induced inhibition of electrically evoked [3H]acetylcholine (ACh) overflow in rat striatal slices. The present study examines the effects of fluoxetine (FLU)-induced and exogenous serotonin (5-HT) on electrically evoked ACh release from striatal slices prepared from adult male and female (in periods of diestrus or proestrus) rats exposed to saline or cocaine in utero. Additionally, we assessed the impact of monoaminergic receptor stimulation on evoked ACh release by superfusion with selective 5-HT2, 5-HT3 and D2 receptor antagonists in the presence of FLU-induced and exogenous 5-HT and measuring the capacity of these drugs to reverse inhibitory effects of 5-HT. Given our previous findings of accentuated inhibition of ACh release by 5-HT3 agonism in striata of pCOC-exposed adult rats, we hypothesized that superfusion of endogenous and exogenous 5-HT would lead to greater suppression of evoked ACh release in this group of animals. Our results indicated that ACh release from slices of all prenatal saline (pSAL) rats was inhibited comparably by FLU (10 microM)-elicited increases in endogenous 5-HT or by increases elicited with application of exogenous 5-HT (5 microM). Robust FLU-mediated inhibition of ACh release was evident in slices from pCOC male and pCOC diestrus female rats vs. their respective PSAL control groups. Superfusion of striatal slices with 5-HT (5 microM) produced a pattern of ACh inhibition similar to that produced by FLU; however, the magnitude of ACh inhibition was consistently greater than that observed with FLU. Inhibition of ACh overflow by FLU was blocked by co-superfusion with ketanserin, a 5-HT2 receptor antagonist. ICS-205,930, a 5-HT3 receptor antagonist or sulpiride, a D2 receptor antagonist. Conversely, serotonergic inhibition of ACh overflow was only blocked by a high concentration of ICS-205,930 (5 microM) and was completely reversed by sulpiride (1 microM). Collectively, these findings demonstrate serotonergic modulation of cholinergic neurons varying as a function of prenatal treatment, sex and, for females, phase of estrous. Inhibition of ACh release by 5-HT appears to be mediated by a complex relationship between 5-HT2, 5-HT3 and D2 receptor regulation, as the blockade of any of these receptors reversed the inhibitory effects of FLU on ACh release. Conversely, in the case of exogenous 5-HT-induced inhibition, only blockade of D2 receptors and high concentrations of the 5-HT3 receptor antagonists were capable of reversing monoaminergic inhibition. These data support the hypothesis that the enhanced serotonergic modulation of ACh neurons in pCOC-exposed animals is largely mediated by dopamine (DA) and reflect a major biochemical persistence of neurodevelopmental adaptations elicited by early cocaine exposure.
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Affiliation(s)
- Carlos A Bolaños
- Psychology Department, Northeastern University, Boston, MA, USA.
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Glatt SJ, Bolaños CA, Trksak GH, Crowder-Dupont C, Jackson D. Prenatal cocaine exposure alters behavioral and neurochemical sensitization to amphetamine in adult rats. Neuropharmacology 2000; 39:599-610. [PMID: 10728881 DOI: 10.1016/s0028-3908(99)00181-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This study examined the neurochemical correlates of amphetamine (AMPH)-induced behavioral effects in prenatally saline (PSAL)-exposed or cocaine (PCOC)-exposed male rats. Pregnant Long-Evans rats received saline or saline containing cocaine hydrochloride (20 mg/kg s.c., b.i.d.) from gestational days 15-21. Animals were left with their biological mothers. Adult offspring were exposed to daily saline or AMPH (0.5, 1.5, or 5 mg/kg, i.p.) injections for 7 days. Behaviors were recorded in an open field during the first hour post-injection. PCOC rats did not exhibit behavioral anomalies during habituation to injection-stress or placement in the open field. PCOC rats displayed significant alterations in stereotyped responses to acute or intermittent exposure to various doses of AMPH. Within 48 h of the final testing day, striatal tissue was obtained from these animals and electrically-evoked [3H]acetylcholine (ACh) release was measured from striatal slices. Superfusion of tissue slices with various concentrations of AMPH (1-1000 nM) produced dose-dependent inhibition of ACh release in both PSAL and PCOC rats repeatedly injected with saline as adults. However, AMPH-induced inhibition of ACh release was decreased in PCOC rats repeatedly injected with AMPH as adults. At 5 mg/kg AMPH, PCOC rats exhibited increased mortality compared to PSAL rats. These data suggest that PCOC exposure produces long-lasting alterations in nigrostriatal transmission and behaviors mediated by this system.
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Affiliation(s)
- S J Glatt
- Department of Psychology, Northeastern University, Boston, MA 02115, USA
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