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Madurai NK, Jantzie LL, Yen E. Sex differences in neonatal outcomes following prenatal opioid exposure. Front Pediatr 2024; 12:1357970. [PMID: 38577634 PMCID: PMC10991792 DOI: 10.3389/fped.2024.1357970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 03/04/2024] [Indexed: 04/06/2024] Open
Abstract
The impact of the opioid epidemic on pregnant people and children is a growing public health crisis. Understanding how opioids affect the developing brain during pregnancy and postnatally remains a critical area of investigation. Biological sex plays a crucial role in all physiologic processes, with the potential for a significant impact on neonatal outcomes, including those infants with opioid exposure. Here, we aim to explore current literature on the effect of sex on neonatal outcomes following prenatal opioid exposure. Sex differences in adults with opioid use disorder have been well studied, including increased mortality among males and higher rates of psychiatric comorbidities and likelihood of relapse in females. However, such differences are not yet well understood in neonates. Emerging clinical data suggest sex-specific effects in infants with prenatal opioid exposure on the expression of genes related to feeding regulation and reward signaling pathways. Increased susceptibility to white matter injury has also been noted in female infants following prenatal opioid exposure. Understanding the impact of sex as a biological variable on neonatal outcomes following prenatal opioid exposure is paramount to improving the health and well-being of infants, children, and adults impacted by the opioid epidemic.
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Affiliation(s)
- Nethra K. Madurai
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lauren L. Jantzie
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Neurodevelopmental Medicine, Phelps Center for Cerebral Palsy and Neurodevelopmental Medicine, Kennedy Krieger Institute, Baltimore, MD, United States
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Division of Pediatric Neurosurgery, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Elizabeth Yen
- Mother Infant Research Institute (MIRI), Tufts Medical Center, Boston, MA, United States
- Division of Newborn Medicine, Tufts Medicine Pediatrics-Boston Children's, Boston, MA, United States
- Department of Pediatrics, Tufts University School of Medicine, Boston, MA, United States
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Searles CT, Harder HJ, Vogt ME, Murphy AZ. Perigestational Opioid Exposure Alters Alcohol-Driven Reward Behaviors in Adolescent Rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.567041. [PMID: 38014019 PMCID: PMC10680700 DOI: 10.1101/2023.11.14.567041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Every fifteen minutes, a baby is born in the U.S. experiencing neonatal opioid withdrawal syndrome (NOWS). Since 2004, the rate of NOWS has increased 7-fold. Clinical studies have established intrauterine exposure to drugs of abuse as a risk factor for adverse health outcomes in adult life, including the propensity for future illicit drug use. Despite extensive knowledge about common mechanisms of action in the neural circuitry that drives opioid and alcohol reward, there is little data on the risks that those born with NOWS face regarding alcohol use later in life. Here, we investigate the impact of perigestational opioid exposure (POE) on the mesolimbic reward system of male and female Sprague Dawley rats at postnatal and adolescent ages. Our laboratory has developed a clinically relevant model for morphine exposure spanning pre-conception to the first week of life. Using this model, we found that POE increased alcohol consumption in female rats under noncontingent conditions, and inversely, reduced alcohol consumption in both male and female rats during operant conditioning sessions. Operant responding was also reduced for sucrose, suggesting that the impact of POE on reward-seeking behaviors is not limited to drugs of abuse. Expression of µ-opioid receptors was also significantly altered in the nucleus accumbens and medial habenula, regions previously shown to play a significant role in reward/aversion circuitry. Significance Statement Early life exposure to opioids is known to alter future drug behavior in rats. In the present study, female rats exposed to morphine via their mothers throughout and after pregnancy exhibited increased alcohol consumption when allowed to consume freely. During operant conditioning, however, male and female rats exposed to gestational morphine decreased consumption of alcohol as well as sucrose. We also observed that gestational morphine exposure altered µ-opioid receptor expression in reward-related brain regions. Our study provides the first evidence of changes in alcohol-directed reward behavior in a gestational opioid exposure rat model.
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Alaee E, Pachenari N, Khani F, Semnanian S, Shojaei A, Azizi H. Enhancement of neuronal excitability in the medial prefrontal cortex following prenatal morphine exposure. Brain Res Bull 2023; 204:110803. [PMID: 37913849 DOI: 10.1016/j.brainresbull.2023.110803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/26/2023] [Accepted: 10/28/2023] [Indexed: 11/03/2023]
Abstract
The clinical use and abuse of opioids during human pregnancy have been widely reported. Several studies have demonstrated that opioids cross the placenta in rats during late gestation, and prenatal morphine exposure has been shown to have negative outcomes in cognitive function. The medial prefrontal cortex (mPFC) is believed to play a crucial role in cognitive processes, motivation, and emotion, integrating neural information from several brain areas and sending converted information to other structures. Dysfunctions in this area have been observed in numerous psychiatric and neurological disorders, including addiction. This current study aimed to compare the electrophysiological properties of mPFC neurons in rat offspring prenatally exposed to morphine. Pregnant rats were injected with morphine or saline twice a day from gestational days 11-18. Whole-cell patch-clamp recordings were performed in male offspring on postnatal days 14-18. All recordings were obtained in current-clamp configuration from mPFC pyramidal neurons to assess their electrophysiological properties. The results revealed that prenatal exposure to morphine shifted the resting membrane potential (RMP) to less negative voltages and increased input resistance and duration of action potentials. However, the amplitude, rise slope, and afterhyperpolarization (AHP) amplitude of the first elicited action potentials were significantly decreased in rats prenatally exposed to morphine. Moreover, the sag voltage ratio was significantly decreased in the prenatal morphine group. Our results suggest that the changes observed in the electrophysiological properties of mPFC neurons indicate an elevation in neuronal excitability following prenatal exposure to morphine.
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Affiliation(s)
- Elham Alaee
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Narges Pachenari
- School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
| | - Fatemeh Khani
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran
| | - Hossein Azizi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
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Neugebauer V, Presto P, Yakhnitsa V, Antenucci N, Mendoza B, Ji G. Pain-related cortico-limbic plasticity and opioid signaling. Neuropharmacology 2023; 231:109510. [PMID: 36944393 PMCID: PMC10585936 DOI: 10.1016/j.neuropharm.2023.109510] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 03/23/2023]
Abstract
Neuroplasticity in cortico-limbic circuits has been implicated in pain persistence and pain modulation in clinical and preclinical studies. The amygdala has emerged as a key player in the emotional-affective dimension of pain and pain modulation. Reciprocal interactions with medial prefrontal cortical regions undergo changes in pain conditions. Other limbic and paralimbic regions have been implicated in pain modulation as well. The cortico-limbic system is rich in opioids and opioid receptors. Preclinical evidence for their pain modulatory effects in different regions of this highly interactive system, potentially opposing functions of different opioid receptors, and knowledge gaps will be described here. There is little information about cell type- and circuit-specific functions of opioid receptor subtypes related to pain processing and pain-related plasticity in the cortico-limbic system. The important role of anterior cingulate cortex (ACC) and amygdala in MOR-dependent analgesia is most well-established, and MOR actions in the mesolimbic system appear to be similar but remain to be determined in mPFC regions other than ACC. Evidence also suggests that KOR signaling generally serves opposing functions whereas DOR signaling in the ACC has similar, if not synergistic effects, to MOR. A unifying picture of pain-related neuronal mechanisms of opioid signaling in different elements of the cortico-limbic circuitry has yet to emerge. This article is part of the Special Issue on "Opioid-induced changes in addiction and pain circuits".
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Affiliation(s)
- Volker Neugebauer
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
| | - Peyton Presto
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Vadim Yakhnitsa
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Nico Antenucci
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Brianna Mendoza
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Guangchen Ji
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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5
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Ahmed N, Kassis A, Malone J, Yang J, Zamzami E, Lin AH, Gordon SM, Gong M, Bardo M, Dalmasso C, Loria AS. Prenatal Morphine Exposure Increases Cardiovascular Disease Risk and Programs Neurogenic Hypertension in the Adult Offspring. Hypertension 2023; 80:1283-1296. [PMID: 37042247 PMCID: PMC10274123 DOI: 10.1161/hypertensionaha.122.20262] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 03/20/2023] [Indexed: 04/13/2023]
Abstract
BACKGROUND The opioid overdose and opioid use disorder epidemics are concomitant with increased metabolic and CVD risk. Although opioid use disorder causes adverse pregnancy outcomes, the offspring's cardiovascular health is understudied. We hypothesized that offspring exposed to in utero morphine exposure (IUME) would show increased CVD risk factors and endogenous opioid system dysregulation. METHODS Sprague Dawley dams were treated with saline (vehicle, n=10) or escalating doses of morphine (5-20 mg/kg per day, SC, n=10) during gestation. Cardiovascular and metabolic parameters were assessed in adult offspring. RESULTS Litter size and pups' birth weight were not different in response to IUME. Female and male IUME offspring showed reduced body length at birth (P<0.05) and body weight from weeks 1 to 3 of life (P<0.05), followed by a catch-up growth effect. By week 16, female and male IUME rats showed reduced tibia length (P<0.05) and fat mass. IUME increases the mean arterial pressure and the depressor response to mecamylamine (5 mg/kg per day, IP) induced by IUME were abolished by a chronic treatment with an alpha-adrenergic receptor blocker (prazosin; 1 mg/kg per day, IP). Although circulating levels of angiotensin peptides were similar between groups, IUME exacerbated maximal ex vivo Ang (angiotensin) II-induced vasoconstriction (P<0.05) and induced endothelial dysfunction in a sex-specific manner (P<0.05). Proenkephalin, an endogenous opioid peptide that lowers blood pressure and sympathetic-mediated vasoconstriction, showed reduced mRNA expression in the heart, aorta, and kidneys from morphine versus vehicle group (P<0.05). CONCLUSIONS Among the effects of IUME, neurogenic hypertension, vascular dysfunction, and metabolic dysfunction could be associated with the dysregulation of the endogenous opioid system.
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Affiliation(s)
- Nermin Ahmed
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536
| | - Alana Kassis
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536
| | - Jena Malone
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536
| | - Jodie Yang
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536
| | - Esraa Zamzami
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536
| | - An-Hsuan Lin
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40536
| | - Scott M. Gordon
- SAHA Cardiovascular Center, University of Kentucky, Lexington, KY 40536
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40536
| | - Ming Gong
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40536
| | - Michael Bardo
- Department of Psychology, College of Arts and Sciences, University of Kentucky, Lexington, KY 40536
| | - Carolina Dalmasso
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536
| | - Analia S. Loria
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536
- SAHA Cardiovascular Center, University of Kentucky, Lexington, KY 40536
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Zhang J, Song C, Dai J, Li L, Yang X, Chen Z. Mechanism of opioid addiction and its intervention therapy: Focusing on the reward circuitry and mu‐opioid receptor. MedComm (Beijing) 2022; 3:e148. [PMID: 35774845 PMCID: PMC9218544 DOI: 10.1002/mco2.148] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 05/03/2022] [Accepted: 05/07/2022] [Indexed: 11/09/2022] Open
Affiliation(s)
- Jia‐Jia Zhang
- National Translational Science Center for Molecular Medicine & Department of Cell Biology The Fourth Military Medical University Xi'an China
| | - Chang‐Geng Song
- Department of Neurology Xijing Hospital The Fourth Military Medical University Xi'an China
| | - Ji‐Min Dai
- Department of Hepatobiliary Surgery Xijing Hospital The Fourth Military Medical University Xi'an China
| | - Ling Li
- National Translational Science Center for Molecular Medicine & Department of Cell Biology The Fourth Military Medical University Xi'an China
| | - Xiang‐Min Yang
- National Translational Science Center for Molecular Medicine & Department of Cell Biology The Fourth Military Medical University Xi'an China
| | - Zhi‐Nan Chen
- National Translational Science Center for Molecular Medicine & Department of Cell Biology The Fourth Military Medical University Xi'an China
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Effah F, de Gusmão Taveiros Silva NK, Vijayanathan K, Camarini R, Joly F, Taiwo B, Rabot S, Champeil-Potokar G, Bombail V, Bailey A. SEX-DEPENDENT IMPACT OF MICROBIOTA STATUS ON CEREBRAL μ -OPIOID RECEPTOR DENSITY IN FISCHER RATS. Eur J Neurosci 2022; 55:1917-1933. [PMID: 35393704 PMCID: PMC9324823 DOI: 10.1111/ejn.15666] [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: 09/13/2021] [Revised: 03/08/2022] [Accepted: 03/29/2022] [Indexed: 11/29/2022]
Abstract
μ‐opioid receptors (MOPr) play a critical role in social play, reward and pain, in a sex‐ and age‐dependent manner. There is evidence to suggest that sex and age differences in brain MOPr density may be responsible for this variability; however, little is known about the factors driving these differences in cerebral MOPr density. Emerging evidence highlights gut microbiota's critical influence and its bidirectional interaction with the brain on neurodevelopment. Therefore, we aimed to determine the impact of gut microbiota on MOPr density in male and female brains at different developmental stages. Quantitative [3H]DAMGO autoradiographic binding was carried out in the forebrain of male and female conventional (CON) and germ‐free (GF) rats at postnatal days (PND) 8, 22 and 116–150. Significant ‘microbiota status X sex’, ‘age X brain region’ interactions and microbiota status‐ and age‐dependent effects on MOPr binding were uncovered. Microbiota status influenced MOPr levels in males but not females, with higher MOPr levels observed in GF versus CON rats overall regions and age groups. In contrast, no overall sex differences were observed in GF or CON rats. Interestingly, within‐age planned comparison analysis conducted in frontal cortical and brain regions associated with reward revealed that this microbiota effect was restricted only to PND22 rats. Thus, this pilot study uncovers the critical sex‐dependent role of gut microbiota in regulating cerebral MOPr density, which is restricted to the sensitive developmental period of weaning. This may have implications in understanding the importance of microbiota during early development on opioid signalling and associated behaviours.
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Affiliation(s)
- Felix Effah
- Pharmacology Section, St George's University of London, Cranmer Terrace, SW17 0RE, London, UK
| | | | - Katie Vijayanathan
- Pharmacology Section, St George's University of London, Cranmer Terrace, SW17 0RE, London, UK
| | - Rosana Camarini
- Pharmacology Department, Universidade de Sao Paulo, São Paulo, Brazil
| | - Fatima Joly
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Benjamin Taiwo
- Pharmacology Section, St George's University of London, Cranmer Terrace, SW17 0RE, London, UK
| | - Sylvie Rabot
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | | | - Vincent Bombail
- UMR PNCA, AgroParisTech, INRAE, Université Paris-Saclay, Paris, France
| | - Alexis Bailey
- Pharmacology Section, St George's University of London, Cranmer Terrace, SW17 0RE, London, UK
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8
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Grecco GG, Haggerty DL, Reeves KC, Gao Y, Maulucci D, Atwood BK. Prenatal opioid exposure reprograms the behavioural response to future alcohol reward. Addict Biol 2022; 27:e13136. [PMID: 35229956 PMCID: PMC8896285 DOI: 10.1111/adb.13136] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/10/2021] [Accepted: 12/17/2021] [Indexed: 12/20/2022]
Abstract
As the opioid crisis has continued to grow, so has the number of infants exposed to opioids during the prenatal period. A growing concern is that prenatal exposure to opioids may induce persistent neurological changes that increase the propensity for future addictions. Although alcohol represents the most likely addictive substance that the growing population of prenatal opioid exposed will encounter as they mature, no studies to date have examined the effect of prenatal opioid exposure on future sensitivity to alcohol reward. Using a recently developed mouse model of prenatal methadone exposure (PME), we investigated the rewarding properties of alcohol and alcohol consumption in male and female adolescent PME and prenatal saline exposed (PSE) control animals. Conditioned place preference to alcohol was disrupted in PME offspring in a sex-dependent manner with PME males exhibiting resistance to the rewarding properties of alcohol. Repeated injections of alcohol revealed enhanced sensitivity to the locomotor-stimulating effects of alcohol specific to PME females. PME males consumed significantly more alcohol over 4 weeks of alcohol access relative to PSE males and exhibited increased resistance to quinine-adulterated alcohol. Further, a novel machine learning model was developed to employ measured differences in alcohol consumption and drinking microstructure to reliably predict prenatal exposure. These findings indicate that PME alters the sensitivity to alcohol reward in adolescent mice in a sex-specific manner and suggests prenatal opioid exposure may induce persistent effects on reward neurocircuitry that can reprogram offspring behavioural response to alcohol later in life.
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Affiliation(s)
- Gregory G. Grecco
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Indiana University School of Medicine, Medical Scientist Training Program, Indianapolis, IN 46202
| | - David L. Haggerty
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Kaitlin C. Reeves
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yong Gao
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Danielle Maulucci
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Brady K. Atwood
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Corresponding Author: Brady K. Atwood, Ph.D. Department of Pharmacology and Toxicology, Contact: 320 W. 15th St, Indianapolis, IN 46202, NB 400-C. phone: 317-274-8917.
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9
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Radhakrishnan R, Brown BP, Haas DM, Zang Y, Sparks C, Sadhasivam S. Pilot study of fetal brain development and morphometry in prenatal opioid exposure and smoking on fetal MRI. J Neuroradiol 2022; 49:53-58. [PMID: 33418054 PMCID: PMC8255323 DOI: 10.1016/j.neurad.2020.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 01/03/2023]
Abstract
PURPOSE The purpose of this study was to assess for any differences in brain maturation, structure and morphometry in fetuses exposed to opioids in utero, compared to non-opioid exposed fetuses on fetal MRI. METHODS We performed a prospective study in pregnant women using opioids and healthy pregnant women without prenatal opioid use. We evaluated brain maturation, structure, and morphometry on second or third trimester fetal MRI and assessed group differences. RESULTS 28 pregnant women were enrolled, 12 with opioid exposure (average gestational age 33.67, range 28-39 w), 9 of whom also smoked, and 16 without opioid exposure (average gestational age 32.53, range 27-38 w). There was a significant difference in the anteroposterior diameter of the fetal cerebellar vermis in the opioid exposed fetuses compared to non-opioid exposed fetuses (p = 0.004). There were no significant differences in brain biparietal diameter, fronto-occipital diameter, transverse cerebellar diameter and anteroposterior dimension of the pons in opioid exposed fetuses compared to non-opioid exposed fetuses. There were no abnormalities in brain maturation and no major brain structural abnormalities in the opioid exposed fetuses. CONCLUSION Smaller fetal anteroposterior cerebellar vermian dimension was associated with in utero opioid exposure. There were no abnormalities in brain maturation or major structural abnormalities in fetuses exposed to opioids.
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Affiliation(s)
- Rupa Radhakrishnan
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN
| | - Brandon P. Brown
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN
| | - David M. Haas
- Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN
| | - Yong Zang
- Department of Biostatistics, Indiana University School of Medicine, Indianapolis, IN
| | - Christina Sparks
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN
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10
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Azadi M, Moazen P, Wiskerke J, Semnanian S, Azizi H. Preconception paternal morphine exposure leads to an impulsive phenotype in male rat progeny. Psychopharmacology (Berl) 2021; 238:3435-3446. [PMID: 34427719 DOI: 10.1007/s00213-021-05962-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 08/09/2021] [Indexed: 11/29/2022]
Abstract
RATIONALE Identifying the long-term neurocognitive implications of opioid addiction may further our understanding of the compulsive nature of this brain disorder. The aim of this study was to examine the effects of paternal adolescent opiate exposure on cognitive performance (visual attention, impulsivity, and compulsivity) in the next generation. METHODS Male Wistar rats received escalating doses of morphine (2.5-25 mg/kg, s.c.) or saline for 10 days during adolescence (P30-39). In adulthood (P70-80), these rats were allowed to mate with drug-naive females. Male offspring from morphine- and saline-exposed sires, once in adulthood, were trained and tested in the 5-choice serial reaction time test (5-CSRTT) to evaluate their cognitive abilities under baseline, drug-free conditions as well as following acute (1, 3, 5 mg/kg morphine) and subchronic morphine (5 mg/kg morphine for 5 days) treatment. Behavioral effects of the opioid receptor antagonist naloxone were also assessed. RESULTS Morphine-sired offspring exhibited delayed learning when the shortest stimulus duration (1 s) was introduced, i.e., when cognitive load was highest. These subjects also exhibited a reduced ability to exert inhibitory control, as reflected by increased premature and perseverative responding under drug-free baseline conditions in comparison to saline-sired rats. These impairments could not be reversed by administration of naloxone. Moreover, impulsive behavior was further enhanced in morphine-sired rats following acute and subchronic morphine treatment. CONCLUSION Paternal opiate exposure during adolescence was found to primarily impair inhibitory control in male progeny. These results further our understanding of the long-term costs and risk of opioid abuse, extending across generations.
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Affiliation(s)
- Maryam Azadi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Parisa Moazen
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Joost Wiskerke
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Hossein Azizi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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11
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Allen MC, Moog NK, Buss C, Yen E, Gustafsson HC, Sullivan EL, Graham AM. Co-occurrence of preconception maternal childhood adversity and opioid use during pregnancy: Implications for offspring brain development. Neurotoxicol Teratol 2021; 88:107033. [PMID: 34601061 PMCID: PMC8578395 DOI: 10.1016/j.ntt.2021.107033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 09/20/2021] [Accepted: 09/24/2021] [Indexed: 12/11/2022]
Abstract
Understanding of the effects of in utero opioid exposure on neurodevelopment is a priority given the recent dramatic increase in opioid use among pregnant individuals. However, opioid abuse does not occur in isolation-pregnant individuals abusing opioids often have a significant history of adverse experiences in childhood, among other co-occurring factors. Understanding the specific pathways in which these frequently co-occurring factors may interact and cumulatively influence offspring brain development in utero represents a priority for future research in this area. We highlight maternal history of childhood adversity (CA) as one such co-occurring factor that is more prevalent among individuals using opioids during pregnancy and which is increasingly shown to affect offspring neurodevelopment through mechanisms beginning in utero. Despite the high incidence of CA history in pregnant individuals using opioids, we understand very little about the effects of comorbid prenatal opioid exposure and maternal CA history on fetal brain development. Here, we first provide an overview of current knowledge regarding effects of opioid exposure and maternal CA on offspring neurodevelopment that may occur during gestation. We then outline potential mechanistic pathways through which these factors might have interactive and cumulative influences on offspring neurodevelopment as a foundation for future research in this area.
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Affiliation(s)
- Madeleine C Allen
- Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, United States
| | - Nora K Moog
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Psychology, Luisenstrasse 57, 10117 Berlin, Germany
| | - Claudia Buss
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Psychology, Luisenstrasse 57, 10117 Berlin, Germany; Development, Health and Disease Research Program, University of California, Irvine, 837 Health Sciences Drive, Irvine, California 92697, United States
| | - Elizabeth Yen
- Department of Pediatrics, Tufts Medical Center, Boston, MA 02111, United States
| | - Hanna C Gustafsson
- Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, United States
| | - Elinor L Sullivan
- Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, United States; Division of Neuroscience, Oregon National Primate Research Center, 505 NW 185(th) Ave., Beaverton, OR 97006, United States; Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, United States
| | - Alice M Graham
- Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, United States.
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12
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Vassoler FM, Wimmer ME. Consequences of Parental Opioid Exposure on Neurophysiology, Behavior, and Health in the Next Generations. Cold Spring Harb Perspect Med 2021; 11:a040436. [PMID: 32601130 PMCID: PMC8485740 DOI: 10.1101/cshperspect.a040436] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Substance abuse and the ongoing opioid epidemic represents a large societal burden. This review will consider the long-term impact of opioid exposure on future generations. Prenatal, perinatal, and preconception exposure are reviewed with discussion of both maternal and paternal influences. Opioid exposure can have long-lasting effects on reproductive function, gametogenesis, and germline epigenetic programming, which can influence embryogenesis and alter the developmental trajectory of progeny. The potential mechanisms by which preconception maternal and paternal opioid exposure produce deleterious consequences on the health, behavior, and physiology of offspring that have been identified by clinical and animal studies will be discussed. The timing, nature, dosing, and duration of prenatal opioid exposure combined with other important environmental considerations influence the extent to which these manipulations affect parents and their progeny. Epigenetic inheritance refers to the transmission of environmental insults across generations via mechanisms independent of the DNA sequence. This topic will be further explored in the context of prenatal, perinatal, and preconception opioid exposure for both the maternal and paternal lineage.
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Affiliation(s)
- Fair M Vassoler
- Tufts University, Cummings School of Veterinary Medicine, Grafton, Massachusetts 01536, USA
| | - Mathieu E Wimmer
- Department of Psychology and Program in Neuroscience, Temple University, Philadelphia, Pennsylvania 19122, USA
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13
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Alaee E, Moazen P, Pattij T, Semnanian S, Azizi H. Prenatal exposure to morphine impairs attention and impulsivity in adult rats. Psychopharmacology (Berl) 2021; 238:2729-2741. [PMID: 34405254 DOI: 10.1007/s00213-021-05888-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 05/27/2021] [Indexed: 10/20/2022]
Abstract
RATIONALE An alarming number of neonates born with prenatal exposure to morphine has resulted from the opioid epidemic; however, the long-term effects of prenatal opioid exposure on offspring behavior remain relatively unknown. In this study, we evaluated whether prenatal exposure to the mu opioid receptor agonist, morphine, has enduring effects on cognitive functions in adult life. METHODS On embryonic days 11-18 (E11-E18), female pregnant rats were injected subcutaneously with either morphine or saline twice daily. Adult male offspring that was prenatally exposed to saline or morphine was trained in the 5-choice serial reaction time test (5-CSRTT) to test their cognitive abilities under baseline conditions. Next, these rats were treated with saline (1 ml/kg), naloxone (1 mg/kg), and acute morphine (1, 3, 5 mg/kg), subcutaneously, once daily and following drug challenges rats were tested in the 5-CSRTT. Meanwhile, behavioral performance on training days between opioid drug challenges were analyzed to monitor possible drug-induced shifts in baseline performance. As a final experiment in order to investigate subchronic exposure to morphine, rats were injected with 5 mg/kg morphine for 5 days and then naloxone in the last day of the experiment (day 6). RESULTS Firstly, during acquisition of a stable baseline in the training phase, rats prenatally exposed to morphine showed delayed learning of the task demands. Furthermore, under baseline responding the rats prenatally exposed to morphine showed declined inhibitory control demonstrated by increased impulsive and compulsive-like responding compared to rats prenatally exposed to saline. Moreover, acute and subchronic morphine challenges in the rats prenatally exposed to morphine caused a deficit in visuospatial attention in comparison with saline treatment as well as the rats prenatally exposed to saline. These effects were abolished by naloxone. CONCLUSION The current findings indicate a direct causal effect of prenatal morphine exposure on inhibitory control and task learning later in life, as well as deficits in attention following morphine exposure in adulthood.
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Affiliation(s)
- Elham Alaee
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Parisa Moazen
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Tommy Pattij
- Department of Anatomy and Neurosciences, Amsterdam Neuroscience, Amsterdam University Medical Centers, VU University Medical Center, Amsterdam, The Netherlands
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Hossein Azizi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran. .,Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
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14
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Yazdanfar N, Farnam A, Sadigh-Eteghad S, Mahmoudi J, Sarkaki A. Enriched environment and social isolation differentially modulate addiction-related behaviors in male offspring of morphine-addicted dams: The possible role of μ-opioid receptors and ΔFosB in the brain reward pathway. Brain Res Bull 2021; 170:98-105. [PMID: 33592274 DOI: 10.1016/j.brainresbull.2021.02.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 01/19/2021] [Accepted: 02/02/2021] [Indexed: 12/20/2022]
Abstract
Prenatal opioids exposure negatively affects the neurobehavioral abilities of children born from dependence dams. Adolescent housing conditions can buffer the detrimental impacts of early life experiences or contradictory can worsen individual psychosocial functions. The present study investigated the effects of maternal morphine dependence and different rearing conditions on behaviors and protein expression in brain reward circuits of male pups. Female Wistar rats a week before conception, during pregnancy and lactation were injected twice daily with escalating doses of morphine or saline. On a postnatal day 21, male pups were weaned and subjected to three different environments for two months: standard (STD), isolated (ISO), or enriched environment (EE). The anxiety and drug-related reward were measured using elevated plus maze, open field test, and conditioned place preference. Western blotting was used to determine the protein level of ΔFosB and μ-opioid receptor proteins in the striatum and the midbrain of male offspring, respectively. Results showed that maternal morphine administration dramatically increased anxiety-like and morphine place preference behaviors in offspring. Also, ISO condition aggravated these behavioral outcomes. While, rearing in EE could attenuate anxiety and morphine conditioning in pups. At molecular levels, maternal morphine exposure and social isolation markedly increased both of ΔFosB and μ-opioid receptor proteins expression. However, rearing in the EE declined ΔFosB protein expression. Together, these findings help to elucidate long lasting impacts of early life morphine exposure and rearing environment on the behavioral and molecular profile of addicted individuals.
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Affiliation(s)
- Neda Yazdanfar
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Neuroscience, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Alireza Farnam
- Research Center of Psychiatry and Behavioral Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Saeed Sadigh-Eteghad
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Javad Mahmoudi
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Alireza Sarkaki
- The Persian Gulf Physiology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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15
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Prenatal opioid exposure and vulnerability to future substance use disorders in offspring. Exp Neurol 2021; 339:113621. [PMID: 33516730 DOI: 10.1016/j.expneurol.2021.113621] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 01/06/2023]
Abstract
The heightened incidence of opioid use during pregnancy has resulted in unprecedented rates of neonates prenatally exposed to opioids. Prenatal opioid exposure (POE) results in significantly adverse medical, developmental, and behavioral outcomes in offspring. Of growing interest is whether POE contributes to future vulnerability to substance use disorders. The effects of POE on brain development is difficult to assess in humans, as the timing, dose, and route of drug exposure together with complex genetic and environmental factors affect susceptibility to addiction. Preclinical models of POE have allowed us to avoid methodological difficulties and confounding factors of POE in humans. Here, we review the effects of maternal opioid exposure on the developing brain with an emphasis on the neurobiological basis of drug addiction and on preclinical models of POE and their limitations. These studies have indicated that POE increases self-administration of drugs, reward-driven behaviors in the conditioned place paradigm, and locomotor sensitization. While addiction is multifaceted and vulnerability to drug addiction is still inconclusive in human studies of prenatally exposed infants, animal studies do provide a noteworthy corroboration of negative behavioral outcomes.
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Prenatal Opioid Exposure Enhances Responsiveness to Future Drug Reward and Alters Sensitivity to Pain: A Review of Preclinical Models and Contributing Mechanisms. eNeuro 2020; 7:ENEURO.0393-20.2020. [PMID: 33060181 PMCID: PMC7768284 DOI: 10.1523/eneuro.0393-20.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/01/2020] [Accepted: 10/05/2020] [Indexed: 12/21/2022] Open
Abstract
The opioid crisis has resulted in an unprecedented number of neonates born with prenatal opioid exposure (POE); however, the long-term effects of POE on offspring behavior and neurodevelopment remain relatively unknown. The advantages and disadvantages of the various preclinical POE models developed over the last several decades are discussed in the context of clinical and translational relevance. Although considerable and important variability exists among preclinical models of POE, the examination of these preclinical models has revealed that opioid exposure during the prenatal period contributes to maladaptive behavioral development as offspring mature including an altered responsiveness to rewarding drugs and increased pain response. The present review summarizes key findings demonstrating the impact of POE on offspring drug self-administration (SA), drug consumption, the reinforcing properties of drugs, drug tolerance, and other reward-related behaviors such as hypersensitivity to pain. Potential underlying molecular mechanisms which may contribute to this enhanced addictive phenotype in POE offspring are further discussed with special attention given to key brain regions associated with reward including the striatum, prefrontal cortex (PFC), ventral tegmental area (VTA), hippocampus, and amygdala. Improvements in preclinical models and further areas of study are also identified which may advance the translational value of findings and help address the growing problem of POE in clinical populations.
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17
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Neuroimaging in infants with prenatal opioid exposure: Current evidence, recent developments and targets for future research. J Neuroradiol 2020; 48:112-120. [PMID: 33065196 DOI: 10.1016/j.neurad.2020.09.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 09/28/2020] [Accepted: 09/29/2020] [Indexed: 12/29/2022]
Abstract
Prenatal opioid exposure (POE) has shown to be a risk factor for adverse long-term cognitive and behavioral outcomes in offspring. However, the neural mechanisms of these outcomes remain poorly understood. While preclinical and human studies suggest that these outcomes may be due to opioid-mediated changes in the fetal and early postnatal brain, other maternal, social, and environmental factors are also shown to play a role. Recent neuroimaging studies reveal brain alterations in children with POE. Early neuroimaging and novel methodology could provide an in vivo mechanistic understanding of opioid mediated alterations in developing brain. However, this is an area of ongoing research. In this review we explore recent imaging developments in POE, with emphasis on the neonatal and infant brain, and highlight some of the challenges of imaging the developing brain in this population. We also highlight evidence from animal models and imaging in older children and youth to understand areas where future research may be targeted in infants with POE.
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18
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Kongstorp M, Bogen IL, Steinsland S, Nerem E, Salih TW, Stiris T, Andersen JM. Prenatal exposure to methadone or buprenorphine alters µ-opioid receptor binding and downstream signaling in the rat brain. Int J Dev Neurosci 2020; 80:443-453. [PMID: 32484968 DOI: 10.1002/jdn.10043] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/14/2020] [Accepted: 05/27/2020] [Indexed: 11/11/2022] Open
Abstract
There is a growing concern related to the use of opioid maintenance treatment during pregnancy. Studies in both humans and animals have reported reduced cognitive functioning in offspring prenatally exposed to methadone or buprenorphine; however, little is known about the neurobiological mechanisms underlying these impairments. To reveal possible neurobiological effects of such in utero exposure, we examined brain tissue from methadone- and buprenorphine-exposed rat offspring previously shown to display impaired learning and memory. We studied µ-opioid receptor (MOR) and N-methyl-D-aspartate receptor (NMDAR) binding in the rat offspring cerebrum during development and in the hippocampus at young adulthood. Moreover, we examined activation of the Ca2+ /calmodulin-dependent protein kinase II (CaMKII) and the extracellular signal-regulated kinase (ERK), which are central in the downstream signaling of these receptors. The methadone- and buprenorphine-exposed rat pups displayed reduced MOR binding up to two weeks after birth, whereas the NMDAR binding was unaffected. Prenatal exposure to methadone or buprenorphine also resulted in decreased activation of CaMKII and/or ERK during development, while young adult offspring displayed increased hippocampal ERK activation. In conclusion, our findings suggest that prenatal exposure to exogenous opioids, such as methadone or buprenorphine, may disturb the endogenous opioid system during development, with long-term effects on proteins important for cognitive functioning.
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Affiliation(s)
- Mette Kongstorp
- Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Inger Lise Bogen
- Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway
- Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Synne Steinsland
- Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway
| | - Elisabeth Nerem
- Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway
| | | | - Tom Stiris
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Neonatal Intensive Care, Oslo University Hospital, Oslo, Norway
| | - Jannike Mørch Andersen
- Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway
- Department of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
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19
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Bendová Z, Pačesová D, Novotný J. The day-night differences in ERK1/2, GSK3β activity and c-Fos levels in the brain, and the responsiveness of various brain structures to morphine. J Comp Neurol 2020; 528:2471-2495. [PMID: 32170720 DOI: 10.1002/cne.24906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 02/17/2020] [Accepted: 03/09/2020] [Indexed: 11/12/2022]
Abstract
As with other drugs or pharmaceuticals, opioids differ in their rewarding or analgesic effects depending on when they are applied. In the previous study, we have demonstrated the day/night difference in the sensitivity of the major circadian clock in the suprachiasmatic nucleus to a low dose of morphine, and showed the bidirectional effect of morphine on pERK1/2 and pGSK3β levels in the suprachiasmatic nucleus depending on the time of administration. The main aim of this study was to identify other brain structures that respond differently to morphine depending on the time of its administration. Using immunohistochemistry, we identified 44 structures that show time-of-day specific changes in c-Fos level and activity of ERK1/2 and GSK3β kinases in response to a single dose of 1 mg/kg morphine. Furthermore, comparison among control groups revealed the differences in the spontaneous levels of all markers with a generally higher level during the night, that is, in the active phase of the day. We thus provide further evidence for diurnal variations in the activity of brain regions outside the suprachiasmatic nucleus indicated by the temporal changes in the molecular substrate. We suggest that these changes are responsible for generating diurnal variation in the reward behavior or analgesic effect of opioid administration.
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Affiliation(s)
- Zdeňka Bendová
- Faculty of Science, Charles University, Prague, Czech Republic.,Department of Sleep Medicine and Chronobiology, National Institute of Mental Health, Klecany, Czech Republic
| | - Dominika Pačesová
- Faculty of Science, Charles University, Prague, Czech Republic.,Department of Sleep Medicine and Chronobiology, National Institute of Mental Health, Klecany, Czech Republic
| | - Jiří Novotný
- Faculty of Science, Charles University, Prague, Czech Republic
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20
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Byrnes EM, Vassoler FM. Modeling prenatal opioid exposure in animals: Current findings and future directions. Front Neuroendocrinol 2018; 51:1-13. [PMID: 28965857 PMCID: PMC5649358 DOI: 10.1016/j.yfrne.2017.09.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/26/2017] [Accepted: 09/27/2017] [Indexed: 01/03/2023]
Abstract
The past decade has seen a drastic rise in the number of infants exposed to opioids in utero. It is unclear what lasting effect this exposure may have on these children. Animal models of prenatal opioid exposure may provide insight into potential areas of vulnerability. The present review summarizes the findings across animal models of prenatal opioid exposure, including exposure to morphine, methadone, buprenorphine, and oxycodone. Details regarding the drug, doses, and duration of treatment, as well as key findings, are summarized in tables with associated references. Finally, significant gaps in the current preclinical literature and future directions are discussed.
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Affiliation(s)
- Elizabeth M Byrnes
- Department of Biomedical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, United States.
| | - Fair M Vassoler
- Department of Biomedical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, United States
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21
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Long-Lasting Alterations in Gene Expression of Postsynaptic Density 95 and Inotropic Glutamatergic Receptor Subunit in the Mesocorticolimbic System of Rat Offspring Born to Morphine-Addicted Mothers. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5437092. [PMID: 29984237 PMCID: PMC6015726 DOI: 10.1155/2018/5437092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 05/06/2018] [Indexed: 11/18/2022]
Abstract
Prenatal exposure to morphine causes altered glutamatergic neurotransmission, which plays an important pathophysiological role for neurobiological basis of opiate-mediated behaviors in such offspring. However, it is still not clear whether such alteration involves gene expression of ionotropic glutamate receptor subunits. In this study, we further studied whether prenatal morphine exposure resulted in long-term changes in the gene expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, N-methyl-d-aspartate (NMDA) receptor, and postsynaptic density 95 in the mesocorticolimbic area (an essential integration circuitry for drug craving behavior), nucleus accumbens (NAc), ventral tegmental area (VTA), and prefrontal cortex (PFC), of rat offspring from morphine-addicted mothers. Experimental results showed that prenatal morphine exposure led to a persistent downregulation of gene expression in the AMPA and NMDA receptor subunit, with a differential manner of decreased magnitudes, at the age of postnatal days 14 (P14) and P30. However, in PFC, the gene expression of the AMPA receptor subunit was not synchronized in observed rat offspring subjected to prenatal morphine exposure. An upregulation of gene expression in the AMPA receptor subunit 3 (GluR3) was persistently observed at P14 and P30. Furthermore, the gene expressions of PSD-95 in NAc, VTA, and PFC were all decreased concurrently. Collectively, the results suggest that prenatal exposure to morphine may initiate molecular mechanisms leading to a long-lasting, differential alteration in gene expression of the inotropic glutamate receptor subunit and PSD-95 in the mesocorticolimbic circuitry in rat offspring. This study raises a possibility in which differential changes in gene expression with a long-lasting manner may play a role for the development of nearly permanent changes in opiate-mediated behaviors, at least in part for the neurobiological pathogenesis in offspring.
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22
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Robust age, but limited sex, differences in mu-opioid receptors in the rat brain: relevance for reward and drug-seeking behaviors in juveniles. Brain Struct Funct 2017; 223:475-488. [PMID: 28871491 PMCID: PMC5772146 DOI: 10.1007/s00429-017-1498-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/12/2017] [Indexed: 11/27/2022]
Abstract
In the brain, the µ-opioid receptor (MOR) is involved in reward-seeking behaviors and plays a pivotal role in the mediation of opioid use disorders. Furthermore, reward-seeking behaviors and susceptibility to opioid addiction are particularly evident during the juvenile period, with a higher incidence of opioid use in males and higher sensitivity to opioids in females. Despite these age and sex differences in MOR-mediated behaviors, little is known regarding potential age and sex differences in the expression of MORs in the brain. Here, we used receptor autoradiography to compare MOR binding densities between juvenile and adult male and female rats. Age differences were found in MOR binding density in 12 out of 33 brain regions analyzed, with 11 regions showing higher MOR binding density in juveniles than in adults. These include the lateral septum, as well as sub-regions of the bed nucleus of the stria terminalis, hippocampus, and thalamus. Sex differences in MOR binding density were observed in only two brain regions, namely, the lateral septum (higher in males) and the posterior cortical nucleus of the amygdala (higher in females). Overall, these findings provide an important foundation for the generation of hypotheses regarding differential functional roles of MOR activation in juveniles versus adults. Specifically, we discuss the possibility that higher MOR binding densities in juveniles may allow for higher MOR activation, which could facilitate behaviors that are heightened during the juvenile period, such as reward and drug-seeking behaviors.
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23
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Gugusheff JR, Bae SE, Rao A, Clarke IJ, Poston L, Taylor PD, Coen CW, Muhlhausler BS. Sex and age-dependent effects of a maternal junk food diet on the mu-opioid receptor in rat offspring. Behav Brain Res 2016; 301:124-31. [DOI: 10.1016/j.bbr.2015.12.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/14/2015] [Accepted: 12/15/2015] [Indexed: 01/09/2023]
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24
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Shen YL, Chen ST, Chan TY, Hung TW, Tao PL, Liao RM, Chan MH, Chen HH. Delayed extinction and stronger drug-primed reinstatement of methamphetamine seeking in rats prenatally exposed to morphine. Neurobiol Learn Mem 2016; 128:56-64. [DOI: 10.1016/j.nlm.2015.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 10/26/2015] [Accepted: 12/10/2015] [Indexed: 01/17/2023]
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25
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Vassoler FM, Wright SJ, Byrnes EM. Exposure to opiates in female adolescents alters mu opiate receptor expression and increases the rewarding effects of morphine in future offspring. Neuropharmacology 2015; 103:112-21. [PMID: 26700246 DOI: 10.1016/j.neuropharm.2015.11.026] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/18/2015] [Accepted: 11/25/2015] [Indexed: 12/22/2022]
Abstract
Prescription opiate use and abuse has increased dramatically over the past two decades, including increased use in adolescent populations. Recently, it has been proposed that use during this critical period may affect future offspring even when use is discontinued prior to conception. Here, we utilize a rodent model to examine the effects of adolescent morphine exposure on the reward functioning of the offspring. Female Sprague Dawley rats were administered morphine for 10 days during early adolescence (post-natal day 30-39) using an escalating dosing regimen. Animals then remained drug free until adulthood at which point they were mated with naïve males. Adult offspring (F1 animals) were tested for their response to morphine-induced (0, 1, 2.5, 5, and 10 mg/kg, s.c.) conditioned place preference (CPP) and context-independent morphine-induced sensitization. Naïve littermates were used to examine mu opiate receptor expression in the nucleus accumbens and ventral tegmental area. Results indicate that F1 females whose mothers were exposed to morphine during adolescence (Mor-F1) demonstrate significantly enhanced CPP to the lowest doses of morphine compared with Sal-F1 females. There were no differences in context-independent sensitization between maternal treatment groups. Protein expression analysis showed significantly increased levels of accumbal mu opiate receptor in Mor-F1 offspring and decreased levels in the VTA. Taken together, these findings demonstrate a shift in the dose response curve with regard to the rewarding effects of morphine in Mor-F1 females which may in part be due to altered mu opiate receptor expression in the nucleus accumbens and VTA.
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Affiliation(s)
- Fair M Vassoler
- Department of Biomedical Sciences, Cummings School of Veterinary Medicine, Tufts University, Peabody Pavilion, 200 Westborough Road, Grafton, MA 01536, USA.
| | - Siobhan J Wright
- Department of Biomedical Sciences, Cummings School of Veterinary Medicine, Tufts University, Peabody Pavilion, 200 Westborough Road, Grafton, MA 01536, USA
| | - Elizabeth M Byrnes
- Department of Biomedical Sciences, Cummings School of Veterinary Medicine, Tufts University, Peabody Pavilion, 200 Westborough Road, Grafton, MA 01536, USA
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26
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Abstract
Drug abuse during pregnancy is a growing problem in all developed countries all over the world. The drugs easily cross the placental barrier into the fetal body and are present also in the maternal milk. Therefore, it may affect the development of the child pre- as well as postnatally. The effects of prenatal drug exposure are long-lasting and persist until adulthood. The present review summarizes the clinical and experimental evidence showing how opioids and psychostimulants can affect maternal behavior of drug-abusing mother and the development of their offspring.
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Affiliation(s)
- R Šlamberová
- Department of Normal, Pathological and Clinical Physiology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
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27
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Ong ZY, Wanasuria AF, Lin MZ, Hiscock J, Muhlhausler BS. Chronic intake of a cafeteria diet and subsequent abstinence. Sex-specific effects on gene expression in the mesolimbic reward system. Appetite 2013; 65:189-99. [DOI: 10.1016/j.appet.2013.01.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 01/08/2013] [Accepted: 01/13/2013] [Indexed: 10/27/2022]
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28
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Bajic D, Commons KG, Soriano SG. Morphine-enhanced apoptosis in selective brain regions of neonatal rats. Int J Dev Neurosci 2013; 31:258-66. [PMID: 23499314 DOI: 10.1016/j.ijdevneu.2013.02.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 02/09/2013] [Accepted: 02/28/2013] [Indexed: 12/12/2022] Open
Abstract
Prolonged neonatal opioid exposure has been associated with: antinociceptive tolerance, long-term neurodevelopmental delay, cognitive, and motor impairment. Morphine has also been shown to induce apoptotic cell death in vitro studies, but its in vivo effect in developing rat brain is unknown. Thus, we hypothesized that prolongued morphine administration in neonatal rats in a model of antinociceptive tolerance and dependence is associated with increased neuroapoptosis. We analyzed neonatal rats from the following groups (1) naïve group (n=6); (2) control group (normal saline (NS), n=5), and (3) morphine group (n=8). Morphine sulfate or equal volume of NS was injected subcutaneously twice daily for 6½ days starting on postnatal day (PD) 1. Development of antinociceptive tolerance was previously confirmed by Hot Plate test on the 7th day. Evidence of neuronal and glial apoptosis was determined by cleaved caspase-3 immunofluorescence combined with specific markers. At PD7, morphine administration after 6½ days significantly increased the density of apoptotic cells in the cortex and amygdala, but not in the hippocampus, hypothalamus, or periaqueductal gray. Apoptotic cells exhibited morphology analogous to neurons. Irrespective of the treatment, only a very few individual microglia but not astrocytes were caspase-3 positive. In summary, repeated morphine administration in neonatal rats (PD1-7) is associated with increased supraspinal apoptosis in distinct anatomical regions known to be important for sensory (cortex) and emotional memory processing (amygdala). Brain regions important for learning (hippocampus), and autonomic and nociceptive processing (hypothalamus and periaqueductal gray) were not affected. Lack of widespread glial apoptosis or robust glial activation following repeated morphine administration suggests that glia might not be affected by chronic morphine at this early age. Future studies should investigate long-term behavioral sequelae of demonstrated enhanced apoptosis associated with prolonged morphine administration in a neonatal rat model.
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Affiliation(s)
- Dusica Bajic
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, 300 Longwood Avenue, Bader 3, Boston, MA 02115, USA.
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Perinatal overnutrition and the programming of food preferences: pathways and mechanisms. J Dev Orig Health Dis 2012; 3:299-308. [DOI: 10.1017/s204017441200030x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
One of the major contributing factors to the continuous rise in obesity rates is the increase in caloric intake, which is driven to a large extent by the ease of access and availability of palatable high-fat, high-sugar ‘junk foods’. It is also clear that some individuals are more likely to overindulge in these foods than others; however, the factors that determine an individual's susceptibility towards the overconsumption of palatable foods are not well understood. There is growing evidence that an increased preference for these foods may have its origins early in life. Recent work from our group and others has reported that in utero and early life exposure to these palatable foods in rodents increased the offspring's preference towards foods high in fat and sugar. One of the potential mechanisms underlying the programming of food preferences is the altered development of the mesolimbic reward system, a system that plays an important role in driving palatable food intake in adults. The aim of this review is to explore the current knowledge of the programming of food preferences, a relatively new and emerging area in the DOHAD field, with a particular focus on maternal overnutrition, the development of the mesolimbic reward system and the biological mechanisms which may account for the early origins of an increased preference for palatable foods.
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Changes in adaptability following perinatal morphine exposure in juvenile and adult rats. Eur J Pharmacol 2010; 654:166-72. [PMID: 21147096 DOI: 10.1016/j.ejphar.2010.11.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 11/16/2010] [Accepted: 11/23/2010] [Indexed: 11/22/2022]
Abstract
The problem of drug abuse among pregnant women causes a major concern. The aim of the present study was to examine the adaptive consequences of long term maternal morphine exposure in offspring at different postnatal ages, and to see the possibility of compensation, as well. Pregnant rats were treated daily with morphine from the day of mating (on the first two days 5mg/kgs.c. than 10mg/kg) until weaning. Male offspring of dams treated with physiological saline served as control. Behavior in the elevated plus maze (EPM; anxiety) and forced swimming test (FST; depression) as well as adrenocorticotropin and corticosterone hormone levels were measured at postpartum days 23-25 and at adult age. There was only a tendency of spending less time in the open arms of the EPM in morphine treated rats at both ages, thus, the supposed anxiogenic impact of perinatal exposure with morphine needs more focused examination. In response to 5min FST morphine exposed animals spent considerable longer time with floating and shorter time with climbing at both ages which is an expressing sign of depression-like behavior. Perinatal morphine exposure induced a hypoactivity of the stress axis (adrenocorticotropin and corticosterone elevations) to strong stimulus (FST). Our results show that perinatal morphine exposure induces long term depression-like changes. At the same time the reactivity to the stress is failed. These findings on rodents presume that the progenies of morphine users could have lifelong problems in adaptive capability and might be prone to develop psychiatric disorders.
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He X, Bao Y, Li Y, Sui N. The effects of morphine at different embryonic ages on memory consolidation and rewarding properties of morphine in day-old chicks. Neurosci Lett 2010; 482:12-6. [DOI: 10.1016/j.neulet.2010.06.074] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 06/23/2010] [Accepted: 06/27/2010] [Indexed: 10/19/2022]
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Chiang YC, Hung TW, Lee CWS, Yan JY, Ho IK. Enhancement of tolerance development to morphine in rats prenatally exposed to morphine, methadone, and buprenorphine. J Biomed Sci 2010; 17:46. [PMID: 20529288 PMCID: PMC2890660 DOI: 10.1186/1423-0127-17-46] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 06/07/2010] [Indexed: 12/02/2022] Open
Abstract
Background Abuse of addictive substances is a serious problem that has a significant impact on areas such as health, the economy, and public safety. Heroin use among young women of reproductive age has drawn much attention around the world. However, there is a lack of information on effects of prenatal exposure to opioids on their offspring. In this study, an animal model was established to study effects of prenatal exposure to opioids on offspring. Methods Female pregnant Sprague-Dawley rats were sub-grouped to receive (1) vehicle, (2) 2-4 mg/kg morphine (1 mg/kg increment per week), (3) 7 mg/kg methadone, and (4) 3 mg/kg buprenorphine, subcutaneously, once or twice a day from E3 to E20. The experiments were conducted on animals 8-12 weeks old and with body weight between 250 and 350 g. Results Results showed that prenatal exposure to buprenorphine caused higher mortality than other tested substance groups. Although we observed a significantly lower increase in body weight in all of the opioid-administered dams, the birth weight of the offspring was not altered in all treated groups. Moreover, no obvious behavioral abnormality or body-weight difference was noted during the growing period (8-12 weeks) in all offspring. When the male offspring received morphine injection twice a day for 4 days, the prenatally opioid-exposed rats more quickly developed a tolerance to morphine (as shown by the tail-flick tests), most notably the prenatally buprenorphine-exposed offspring. However, the tolerance development to methadone or buprenorphine was not different in offspring exposed prenatally to methadone or buprenorphine, respectively, when compared with that of the vehicle controlled group. Similar results were also obtained in the female animals. Conclusions Animals prenatally exposed to morphine, methadone, or buprenorphine developed tolerance to morphine faster than their controlled mates. In our animal model, prenatal exposure to buprenorphine also resulted in higher mortality and much less sensitivity to morphine-induced antinociception than prenatal exposure to morphine or methadone. This indicates that buprenorphine in higher doses may not be an ideal maintenance drug for treating pregnant women. This study provides a reference in selecting doses for clinical usage in treating pregnant heroin addicts.
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Affiliation(s)
- Yao-Chang Chiang
- Division of Mental Health & Addiction Medicine, Institute of Population Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 35053, Taiwan, ROC
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Sun H, Che Y, Liu X, Ma Y. Detour behavior changes associated with prenatal morphine exposure in 11-day-old chicks. Int J Dev Neurosci 2010; 28:239-43. [PMID: 20170722 DOI: 10.1016/j.ijdevneu.2010.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 12/31/2009] [Accepted: 02/02/2010] [Indexed: 10/19/2022] Open
Abstract
The central nervous system exhibits remarkable plasticity in early life. Prenatal morphine exposure may induce adverse behavioral effects on the neonate and the developing offspring. In the present study, we investigated the effect of prenatal morphine exposure (daily from embryonic days 12-16, 20mg/kg) on 11-day-old chicks using two forms of spatial paradigms: one trial detour behavior task in which animals must bypass an obstacle to reach the desired goal without any training and detour learning task which required several trials of training to reach the detour criterion. The results showed that, on the condition that chicks could successfully detour in the first trial, morphine exposed chicks exhibited longer detour latency to finish the task, coupled by a preference for turning right versus turning left. In contrast, no significant difference in learning and memory was found in detour learning task between morphine exposed chicks and saline chicks. These findings suggest specific behavioral changes associated with prenatal exposure to opioids during mid to late gestation, also raise attention to the possible health hazard from pregnancy drug use in everyday life.
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Affiliation(s)
- Huaying Sun
- State Key Laboratory of Brain and Cognitive Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, PR China
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Mei B, Niu L, Cao B, Huang D, Zhou Y. Prenatal morphine exposure alters the layer II/III pyramidal neurons morphology in lateral secondary visual cortex of juvenile rats. Synapse 2010; 63:1154-61. [PMID: 19670310 DOI: 10.1002/syn.20694] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Altered cortical neuronal morphology and juvenile behavior manifestation by prenatal morphine exposure were well documented. However, this developmental morphine exposure affect the lateral secondary visual area (V2L), which may be critically involved in the multisensory of auditory and visual stimulus, remained poorly understood. To clarify the neuronal architecture changes possibly occurring in the V2L, Golgi-Cox staining was used in this study to count dendritic length and the spine density of the layer II/III pyramidal neurons in the V2L of the juvenile rats (postnatal day 25, PND25) prenatally exposed to morphine (gestation days 11-18). Quantitative analysis showed that prenatal morphine exposure decreased the total length, branch number, and spine density of the layer II/III pyramidal neurons in the V2L, and selectively altered the total length of the basal dendrites but not of the apical dendrites. The findings may provide the mechanistic understanding of the behavioral changes in the children whose mothers abuse opiates during pregnancy.
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Affiliation(s)
- Bin Mei
- Department of Biology, School of Basic Medical Science, Anhui Medical University, Hefei, Anhui 230032, People's Republic of China
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Niu L, Cao B, Zhu H, Mei B, Wang M, Yang Y, Zhou Y. Impaired in vivo synaptic plasticity in dentate gyrus and spatial memory in juvenile rats induced by prenatal morphine exposure. Hippocampus 2009; 19:649-57. [PMID: 19115391 DOI: 10.1002/hipo.20540] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Prenatal morphine exposure induces neurobiological changes, including deficits in learning and memory, in juvenile rat offspring. However the effects of this exposure on hippocampal plasticity, which is critical for learning and memory processes, are not well understood. The present study investigates the alterations of spatial memory and in vivo hippocampal synaptic plasticity in juvenile rats prenatally exposed to morphine. On gestation days 11-18, pregnant rats were randomly chosen to be injected twice daily with morphine or saline. Each juvenile offspring (postnatal day 22-31) performed one two-trial Y-maze task to evaluate spatial memory. Afterwards, the in vivo field excitatory postsynaptic potential (fEPSP) and population spike (PS) were recorded in the perforant path dentate gyrus (DG) pathway in the hippocampus. Prenatal morphine exposure reduced depotentiation (DP), but not long-term potentiation (LTP), of the EPSP slope. However, both LTP and DP of the EPSP slope were depressed in prenatal morphine-exposed juvenile offspring. The morphine group also showed poorer performance for the Y-maze task than the control group. Depressed PS LTP, but not EPSP LTP, in the morphine group suggested that prenatal morphine exposure changed GABAergic inhibition, which mediates EPSP-spike potentiation. Then a loss of GABA-containing neurons in the DG area of the morphine group was observed using immunohistochemistry. Taken together, our results suggest that prenatal morphine exposure impairs the juvenile offspring's dentate synaptic plasticity and spatial memory, and that decreased GABAergic inhibition may play a role in these effects. These findings might contribute to an explanation for the cognitive deficits in children whose mothers abuse opiates during pregnancy.
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Affiliation(s)
- Lei Niu
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
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Villarreal DM, Derrick B, Vathy I. Prenatal morphine exposure attenuates the maintenance of late LTP in lateral perforant path projections to the dentate gyrus and the CA3 region in vivo. J Neurophysiol 2008; 99:1235-42. [PMID: 18199817 DOI: 10.1152/jn.00981.2007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previously we reported that prenatal exposure to morphine twice daily during gestation decreases proenkephalin levels in adult progeny within the brain, including the dentate gyrus, and alters mu and delta opioid receptors in the hippocampal CA3 region. The lateral aspect of the perforant path contains and releases enkephalin-derived opioid peptides, and induction of long-term potentiation (LTP) in lateral perforant path projections to both the dentate gyrus and the hippocampal CA3 region is blocked by antagonists of opioid receptors. Thus LTP induction at these synapses involves opioid receptor activation mediated by the release of proenkephalin-derived opioid peptides with lateral perforant path activation. Here we show in adult behaving animals, neither LTP induction nor the early phase of LTP (E-LTP) maintenance is altered by prenatal morphine exposure in the lateral perforant path projections to the dentate gyrus and the CA3 region. However, maintenance and longevity of late LTP (L-LTP), as reflected in the magnitude of LTP over days, was attenuated in animals prenatally exposed to morphine. In contrast, in medial perforant path projections to the dentate gyrus and CA3 region, both LTP induction and the maintenance of E- and L-LTP were unaffected by prenatal morphine treatment. Thus a brief prenatal exposure to the opiate morphine produces sustained, and possibly permanent, alterations in L-LTP in the opioidergic lateral perforant path projection. This suggests that prenatal morphine exposure disrupts LTP via disruption of opioid mechanisms involved in LTP maintenance or via disruption of opioid receptor activation during LTP induction, which can subsequently alter LTP maintenance.
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Affiliation(s)
- D M Villarreal
- Cajal Neuroscience Research Center, Department of Biology, University of Texas at San Antonio, TX, USA
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Vathy I, Slamberová R, Liu X. Foster mother care but not prenatal morphine exposure enhances cocaine self-administration in young adult male and female rats. Dev Psychobiol 2007; 49:463-73. [PMID: 17577230 DOI: 10.1002/dev.20240] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The present study was designed to investigate cocaine self-administration in adult male and female rats exposed prenatally to morphine. Pregnant dams were injected two times a day with either saline, analgesic doses of morphine or no drug at all (controls) on gestation Days 11-18. One day after birth, litters were cross-fostered such that control dams were paired with one another and their litters were crossed; saline- and morphine-treated dams were paired and half of each saline litter was crossed with half of each morphine litter. Thus, each mother (control, saline, and morphine) raised half of her own and half of the adopted litter. At the age of 60 days, males and females were trained first to lever press for sucrose pellets and then for cocaine. Once the lever-pressing behavior was learned and baseline level of this activity was established, animals received a cocaine (.5 mg/kg per infusion) reward for each correct response on the active lever during the next 9-day session. The data demonstrate that adult control, saline- and morphine-exposed male rats self-administer cocaine at a similar rate independent of their prenatal treatment. Adult female rats self-administer cocaine at a higher rate than male rats. Further, saline- and morphine-exposed females in diestrus self-administer more than females in proestrus phase of the estrous cycle, while control females show no such differences. In addition, fostering induces increase in cocaine self-administration in all groups of male rats regardless of prenatal drug exposure. In females, the only fostering-induced increase is in prenatally saline-exposed female rats raised by morphine-treated foster mother. Thus, our results suggest that the prenatal drug exposure does not induce changes in lever-pressing behavior for cocaine reward in adult male and female rats, but it sensitizes the animals to postnatal stimuli such as gonadal hormones and/or rearing conditions that result in increased drug self-administration.
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Affiliation(s)
- I Vathy
- Department of Psychiatry and Behavioral Sciences Albert Einstein College of Medicine, 1300 Morris Park Avenue, Ullmann Bldg., 111. Bronx, New York 10461, USA.
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Riley MA, Vathy I. Mid- to late gestational morphine exposure does not alter the rewarding properties of morphine in adult male rats. Neuropharmacology 2006; 51:295-304. [PMID: 16697425 DOI: 10.1016/j.neuropharm.2006.03.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 03/14/2006] [Accepted: 03/19/2006] [Indexed: 11/16/2022]
Abstract
Prenatal exposure to drugs of abuse often leads to physiological and neurobiological abnormalities including decreased brain and body weight, cognitive deficits and behavioral alterations. A handful of studies showed increased vulnerability to drug abuse in prenatally drug-exposed offspring. Our work also demonstrated that prenatal exposure to analgesic doses of morphine during gestation days 11-18 increases mu-opioid receptor density in the nucleus accumbens and central amygdala of adult male rats. Both the nucleus accumbens and central amygdala play important roles in modulating drug-induced reward via the mesolimbic dopaminergic system. Therefore, two types of behavioral paradigms were used to test the hypothesis that the same prenatal morphine exposure would enhance the rewarding effects of morphine, making drug-exposed offspring more vulnerable to abuse this drug in adulthood. All experiments were performed with adult male offspring of saline-injected, morphine-injected or non-injected (control) dams. (1) The unbiased conditioned place preference (CPP) paradigm was used to investigate whether prenatal morphine exposure sensitizes adult male rats to non-contingent morphine reward. These adult animals were conditioned with 0.1, 0.3, 1, 3 or 5 mg/kg morphine. All control, prenatally saline- and morphine-exposed male rats preferred the morphine-paired compartment relative to the saline-paired compartment. However, the magnitude of morphine CPP in adult male rats was not dependent on the conditioning dose of morphine or prenatal morphine exposure. (2) Intravenous morphine self-administration was used to assess the behavioral response to contingent morphine reward. Each rat self-administered one of four doses of morphine (0.3, 1, 2 or 3 mg/kg/infusion). Morphine self-administration was not altered in prenatally morphine-exposed adult male offspring. Control males self-administered significantly less morphine at the lowest dose of morphine than both prenatally saline- and morphine-exposed males. Although our data show that prenatal exposure to an analgesic dose of morphine during the time of opioid receptor appearance does not enhance morphine CPP or self-administration, they do not exclude the possibility that this prenatal morphine exposure enhances the rewarding properties of other drugs of abuse.
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Affiliation(s)
- Michelle A Riley
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Teodorov E, Modena CC, Sukikara MH, Felicio LF. Preliminary study of the effects of morphine treatment on opioid receptor gene expression in brain structures of the female rat. Neuroscience 2006; 141:1225-31. [PMID: 16753266 DOI: 10.1016/j.neuroscience.2006.04.071] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 04/27/2006] [Accepted: 04/28/2006] [Indexed: 11/18/2022]
Abstract
Opioid receptors play an important role in female physiology. They modulate directly and indirectly neuroendocrine phenomena that influence pregnancy maintenance, pain threshold, parturition, lactation, maternal behavior, rewarding and addiction. Thus understanding the gene expression levels of the three major opioid receptors, mu, delta and kappa in different brain regions is essential for investigating dynamic mechanisms of opioidergic transmission. Adult virgin female rats were treated acutely with morphine sulfate (3.5 mg/kg or 20 mg/kg s.c.) or chronically for 5 days (3.5 mg/kg). Rats were killed 1 h after the last injection. In the acute treatment, expression levels for the encoded mu-opioid receptor Oprm1, as detected by reverse transcription-polymerase chain reaction, were significantly decreased in the periaqueductal gray. In chronic treatment, both Oprk1 and Oprm1 expression levels, that encoded kappa and mu-opioid receptor respectively, showed significant decreases in the periaqueductal gray and striatum. Regional changes in opioid receptor gene expression levels might reflect highly specialized roles for these receptors with possible functional meaning for the plasticity of the opioidergic transmission.
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Affiliation(s)
- E Teodorov
- Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Orlando Marques de Paiva, 87, Cidade Universitaria, 05508-900 São Paulo, Brazil
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Bhat R, Chari G, Rao R. Effects of prenatal cocaine, morphine, or both on postnatal opioid (μ) receptor development. Life Sci 2006; 78:1478-82. [PMID: 16242731 DOI: 10.1016/j.lfs.2005.07.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Accepted: 07/13/2005] [Indexed: 11/16/2022]
Abstract
We studied the effects of prenatal cocaine and morphine given separately and in combination on the (1) postnatal brain mu-opioid receptor development and (2) interaction of dopamine with mu receptors. Pregnant rats received single daily intraperitoneal (I.P.) injections of saline, cocaine (20 mg/kg), morphine (2 mg/kg), or the combination of both drugs from day 13 to day 20 of gestation. Postnatal days (P) 1, 7, 14, and 28, whole brains were analyzed for opioid receptor binding and mu mRNA. Prenatal cocaine administered by itself had no significant effect on the ontogeny of brain mu receptors on all the days studied when compared to controls. The morphine-treated group showed a significant increase in mu receptor binding on P1 and P7. Exposure to both cocaine and morphine showed a significant increase in mu receptor density on P1 and P7. In addition, there was also a significant increase in MOR mRNA in both the morphine alone and combination groups. Pretreatment with dopamine D2 receptor antagonist (sulpiride, 20 mg/kg) prior to drug administration showed decreased mu receptor binding on P1 and P7. These results suggest that prenatal exposure to morphine or a combination of cocaine and morphine significantly increases mu receptor density. By P14, mu-opioid receptor binding was no longer different than the control. This may suggest that the effect on receptor may be short-lived and that other key intracellular events may be activated to mediate the long-term effects. Also, the data show that dopaminergic mechanisms are (or opioid-dopamine interaction is) involved in the effects of morphine alone or morphine in combination with cocaine on mu receptor regulation.
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Affiliation(s)
- Rama Bhat
- Department of Pediatrics, M/C 856, University of Illinois at Chicago, 840 S. Wood St., Chicago, IL 60612, USA.
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Slamberová R, Hnatczuk OC, Vathy I. Expression of proopiomelanocortin and proenkephalin mRNA in sexually dimorphic brain regions are altered in adult male and female rats treated prenatally with morphine. ACTA ACUST UNITED AC 2005; 63:399-408. [PMID: 15140157 DOI: 10.1111/j.1399-3011.2004.00134.x] [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: 11/30/2022]
Abstract
The present study demonstrates that prenatal morphine exposure on gestation days 11-18 differentially alters proopiomelanocortin (POMC) and proenkephalin (pENK) mRNA in the hypothalamus and limbic system of adult male and female rats. In adult, prenatally morphine-exposed male rats POMC mRNA levels are decreased in the arcuate nucleus of the hypothalamus (ARC), while the pENK mRNA levels are increased in the paraventricular nucleus of the hypothalamus (PVN) and in the ventrolateral subdivision of the ventromedial nucleus of the hypothalamus (VMH), specifically in the ventrolateral subdivision of the VMH. In adult, prenatally morphine-exposed female rats, POMC mRNA levels in the ARC are increased in ovariectomized (OVX) but not in OVX, estradiol benzoate- (EB) or EB- and progesterone- (P) treated females. In contrast, pENK mRNA levels are decreased in the VMH of morphine-exposed, OVX females and increased in EB-treated females. Further, prenatal morphine exposure decreases pENK mRNA in the ARC and increases it in the medial pre-optic area independently of female gonadal hormones. Finally, POMC mRNA levels are increased in the ARC of saline-exposed, EB- or EB- and P-treated females but not in OVX females. Thus, the present study suggests that prenatal morphine exposure sex and brain region specifically alters the level of POMC and pENK mRNA.
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Affiliation(s)
- R Slamberová
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave, Ull. 111, Bronx, NY 10461, USA
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Hamilton KL, Harris AC, Gewirtz JC, Sparber SB, Schrott LM. HPA axis dysregulation following prenatal opiate exposure and postnatal withdrawal. Neurotoxicol Teratol 2005; 27:95-103. [PMID: 15681124 DOI: 10.1016/j.ntt.2004.09.004] [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: 06/11/2004] [Revised: 09/20/2004] [Accepted: 09/21/2004] [Indexed: 11/20/2022]
Abstract
We examined the effects of prenatal exposure to the long acting opiate l-alpha-acetylmethadol (LAAM) followed by postnatal withdrawal on hypothalamic-pituitary-adrenal (HPA) axis reactivity in neonatal and adult rats and anxiety-like behavior in adult rats. Female rats were treated with LAAM (0, 0.2, or 1.0 mg/kg/day) via oral gavage for 28 days prior to and continuing throughout pregnancy. Pups were fostered at birth to nontreated, lactating dams and underwent opiate withdrawal. On postnatal day (PND) 18, prenatal opiate-exposed male and female rat pups displayed a decreased corticosterone response 2 h after the application of an immunological stressor and 15 min following a social stressor compared to controls. In contrast, in adulthood, prenatal opiate-treated rats showed a heightened corticosterone response compared to prenatal water-treated controls at 3 h, but not 8 h, following an immunological stressor. Males prenatally treated with 1.0 mg/kg LAAM displayed elevated startle responding compared to the other prenatally treated male groups, but there was no effect of prenatal treatment in females. There were no effects of prenatal treatment in the open field test in either sex. These results suggest that prenatal opiate exposure followed by postnatal withdrawal dysregulated the HPA axis response to stressors in the neonate and adult and differentially affected adult anxiety-like behavior in males and females.
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Affiliation(s)
- Kathryn L Hamilton
- Department of Psychology, University of Minnesota, Minneapolis, MN 55455, United States
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Hou Y, Tan Y, Belcheva MM, Clark AL, Zahm DS, Coscia CJ. Differential effects of gestational buprenorphine, naloxone, and methadone on mesolimbic mu opioid and ORL1 receptor G protein coupling. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2004; 151:149-57. [PMID: 15246701 DOI: 10.1016/j.devbrainres.2004.05.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/03/2004] [Indexed: 11/20/2022]
Abstract
In addition to its use for heroin addiction pharmacotherapy in general, buprenorphine has advantages in treating maternal heroin abuse. To examine the gestational effects of buprenorphine on opioid receptor signaling, the [(35)S]-GTP gamma S in situ binding induced by the mu agonist [D-Ala(2),MePhe(4),Gly(5)-ol] enkephalin (DAMGO) or the nociceptin/orphanin FQ (N/OFQ) agonist was measured in mesolimbic structures of pup brains from pregnant rats administered with buprenorphine +/- naloxone, naloxone, or methadone by osmotic minipump. Drug- and gender-based changes in DAMGO- and N/OFQ-induced GTP gamma S binding were discovered in mesolimbic regions of dam, P2, and P7 brains. Buprenorphine and/or methadone gestational treatment attenuated DAMGO-induced GTP gamma S binding in some dam and male P2 mesolimbic regions. Methadone diminished DAMGO-induced GTP gamma S binding in almost all monitored brain regions of the dam but had few effects on their N/OFQ-induced GTP gamma S binding. Naloxone used in combination with buprenorphine blocked the inhibition by buprenorphine alone on DAMGO-induced GTP gamma S binding. In contrast to its inhibitory effects on DAMGO-induced GTP gamma S binding, buprenorphine stimulated N/OFQ-induced GTP gamma S binding in male P2 nucleus accumbens and lateral septum. Brain region-dependent gender differences in DAMGO-induced GTP gamma S binding were seen in P2 pups, and males showed greater sensitivity to buprenorphine and methadone than females. Our findings on mu opioid receptor (MOR) GTP-binding regulatory protein (G protein) coupling and its gender dependency are consistent with our earlier studies on mu receptor binding adaptation induced by buprenorphine in dams and neonatal rats after in utero treatment regimens, and they extend the gestational effects of this opiate to mu and N/OFQ receptor functionality.
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Affiliation(s)
- Yanning Hou
- Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, 1402 S. Grand Boulevard, St. Louis, MO 63104, USA
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Schindler CJ, Slamberová R, Vathy I. Cholera toxin B decreases bicuculline seizures in prenatally morphine- and saline-exposed male rats. Pharmacol Biochem Behav 2004; 77:509-15. [PMID: 15006461 DOI: 10.1016/j.pbb.2003.12.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2003] [Revised: 08/16/2003] [Accepted: 12/08/2003] [Indexed: 11/29/2022]
Abstract
Prenatal morphine exposure on gestation days 11-18 alters bicuculline-induced seizures in rats during development and in adulthood. Adult, morphine-exposed male progeny exhibit an increased latency to bicuculline seizures, which can be reversed by administration of the opioid receptor antagonist naloxone. In chronically morphine-treated adult mice, cholera toxin B (CTX-B) can reverse the effects of chronic morphine administration. Therefore, the present study investigated whether prenatally morphine-exposed rats show a similar response to CTX-B as chronically morphine-treated adult rodents. Prenatally morphine-, saline- and unexposed male progeny were tested for seizure susceptibility with a 7.5-mg/kg intraperitoneal injection of bicuculline in adulthood. CTX-B or saline was injected subcutaneously at 24, 12, and 0.5 h before bicuculline injection. CTX-B decreased the occurrence of bicuculline-induced seizures in both prenatally saline- and morphine-exposed but not unexposed rats. Furthermore, three, but not one, saline injections administered at 12-h intervals prior to bicuculline administration reversed the increase in seizure latency in prenatally morphine-exposed adult males, suggesting an altered responsiveness of the stress system. The present study demonstrates that CTX-B can decrease the occurrence of bicuculline seizures in prenatally stressed rats and that increased seizure latencies in prenatally morphine-exposed male rats may be related to stress responses.
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Affiliation(s)
- Cheryl J Schindler
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Schindler CJ, Slamberová R, Rimanóczy A, Hnactzuk OC, Riley MA, Vathy I. Field-specific changes in hippocampal opioid mRNA, peptides, and receptors due to prenatal morphine exposure in adult male rats. Neuroscience 2004; 126:355-64. [PMID: 15207353 DOI: 10.1016/j.neuroscience.2004.03.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2004] [Indexed: 10/26/2022]
Abstract
Alterations in the opioid system in the hippocampal formation and some of the possible functional consequences were investigated in adult male rats that were prenatally exposed to either saline or morphine (10 mg/kg twice daily on gestational days 11-18). In situ hybridization and Northern blots were used to measure proenkephalin and prodynorphin mRNA, and radioimmunoassays quantified proenkephalin- and prodynorphin-derived peptide levels in the dentate gyrus, CA3, and CA1 subfields of the hippocampal formation. Prenatal morphine exposure in male rats decreases proenkephalin and increases prodynorphin mRNA selectively in the granule cell layer of the dentate gyrus. Similarly, met-enkephalin peptide levels are decreased and dynorphin B peptide levels are increased in the dentate gyrus but not CA3 or CA1 of prenatally morphine-exposed males. In addition, there are decreases in dynorphin-derived peptides in the CA3 subfield. Receptor autoradiography revealed increases in the density of micro but not delta receptor labeling in discrete strata of specific hippocampal subfields in morphine-exposed males. Because alterations in the hippocampal opioid system suggest possible alterations in the excitability of the hippocampal formation, changes in opioid regulation of seizures were examined. Morphine exposure, however, does not alter the latency to onset or number of episodes of wet dog shakes or clonic seizures induced by infusion of 10 nmol [D-Ala2, MePhe4, Gly-ol5]enkephalin into the ventral hippocampal formation. Interestingly, a naloxone (5 mg/kg) injection 30 min before bicuculline administration reverses the increased latency to onset of clonic and tonic-clonic seizures in morphine-exposed males. Thus, the present study suggests that exposure of rats to morphine during early development alters the hippocampal opioid system, suggesting possible consequences for hippocampal-mediated functions.
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Affiliation(s)
- C J Schindler
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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Slamberová R, Bar N, Vathy I. Long-term effects of prenatal morphine exposure on maternal behaviors differ from the effects of direct chronic morphine treatment. Dev Psychobiol 2003; 43:281-9. [PMID: 15027411 DOI: 10.1002/dev.10141] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Previous studies have demonstrated that chronic morphine treatment of pregnant rats alters maternal behavior. Other studies have shown long-term effects of prenatal exposure to morphine, including changes in reproductive behavior in adult females. The present study investigated the effects of prenatal morphine exposure on a variety of maternal behaviors such as nursing, maternal activities, nonmaternal activities, and pup retrieval. Prenatal morphine exposure increased active and decreased passive nursing. There were no differences in maternal activities such as presence in the nest, contact with pups, grooming of pups, and/or manipulation of nest shavings. In the retrieval test, prenatally morphine-exposed mothers were faster in carrying the first pup, retrieving the first pup back to the nest, and returning all pups to the nest than prenatally saline-exposed mothers. Maternal and nonmaternal activities also were affected by the light: dark cycle. All saline- and morphine-exposed mothers nursed more, were more often in the nest, and more often in contact with greater than half of their litter during the light than the dark sessions. On the other hand, nonmaternal activities increased during the dark sessions: Mothers cared for themselves (groomed, ate) more and displayed more rearing and sniffing. Mothers spent more time resting with their eyes closed during the light sessions regardless of prenatal drug exposure. The present study demonstrated that the effect of morphine on maternal behavior is different in adult exposed and prenatally exposed mothers. While direct morphine treatment impaired maternal behaviors, prenatal morphine exposure has the opposite effect.
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Affiliation(s)
- Romana Slamberová
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Slamberová R, Rimanóczy A, Schindler CJ, Vathy I. Cortical and striatal μ-opioid receptors are altered by gonadal hormone treatment but not by prenatal morphine exposure in adult male and female rats. Brain Res Bull 2003; 62:47-53. [PMID: 14596891 DOI: 10.1016/j.brainresbull.2003.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The cerebral cortex (CX), cingulate CX (cgCX), and striatum (STR) play an important role in locomotion, cognition, emotion, and reward-motivated behaviors, and are altered by prenatal morphine exposure. We have demonstrated that delta-opioid receptors in the CX and STR of adult male and female rats are altered by prenatal morphine exposure and gonadal hormonal treatment. Because morphine binds with greater affinity to mu- than delta-opioid receptors, the present study examined the effect of prenatal morphine exposure on mu-opioid receptor density in the CX, cgCX, and STR of adult male and female rats using receptor autoradiography. In Experiment 1, three groups of adult male rats were analyzed: intact, gonadally intact; GNX, gonadectomized; and TP, GNX and testosterone propionate (TP)-treated. In Experiment 2, four groups of adult females were analyzed: OVX, ovariectomized; EB, OVX and estradiol benzoate (EB)-treated; P, OVX and progesterone (P)-treated; and EB+P, OVX and EB- and P-treated. In male rats, GNX and TP males had lower mu-opioid receptor densities in all three brain regions than gonadally intact males regardless of prenatal drug exposure. In female rats, OVX, EB+P-treated females had lower mu-opioid receptor density in the STR than OVX only females regardless of prenatal drug exposure. There were no drug or gonadal hormone effects in the CX or in the cgCX of female rats. Thus, the present study demonstrates that gonadal hormones, and not prenatal morphine exposure, alter the density of mu-opioid receptors in the CX, cgCX, and STR of adult male and female rats.
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Affiliation(s)
- Romana Slamberová
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Ull. 111, Bronx, NY 10461, USA
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