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Reeves KC, Shah N, Muñoz B, Atwood BK. Opioid Receptor-Mediated Regulation of Neurotransmission in the Brain. Front Mol Neurosci 2022; 15:919773. [PMID: 35782382 PMCID: PMC9242007 DOI: 10.3389/fnmol.2022.919773] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/26/2022] [Indexed: 12/15/2022] Open
Abstract
Opioids mediate their effects via opioid receptors: mu, delta, and kappa. At the neuronal level, opioid receptors are generally inhibitory, presynaptically reducing neurotransmitter release and postsynaptically hyperpolarizing neurons. However, opioid receptor-mediated regulation of neuronal function and synaptic transmission is not uniform in expression pattern and mechanism across the brain. The localization of receptors within specific cell types and neurocircuits determine the effects that endogenous and exogenous opioids have on brain function. In this review we will explore the similarities and differences in opioid receptor-mediated regulation of neurotransmission across different brain regions. We discuss how future studies can consider potential cell-type, regional, and neural pathway-specific effects of opioid receptors in order to better understand how opioid receptors modulate brain function.
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Affiliation(s)
- Kaitlin C. Reeves
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Neuroscience, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, United States
| | - Nikhil Shah
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Medical Scientist Training Program, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Braulio Muñoz
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Brady K. Atwood
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
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2
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Umholtz M, Nader ND. Anesthetic Immunomodulation of the Neuroinflammation in Postoperative Cognitive Dysfunction. Immunol Invest 2018; 46:805-815. [PMID: 29058541 DOI: 10.1080/08820139.2017.1373898] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Postoperative delirium and cognitive dysfunction are phenomena that are associated with increases in morbidity, mortality, and resource utilization after surgery. This review scrutinized a number of studies in order to better characterize the biochemical basis for associated cognitive dysfunction and delirium, with particular focus paid to the interactions of the cholinergic system with innate immunity and how the modulation of the immune system contributes to associated neuroinflammation. Despite the clinical impact of postoperative cognitive dysfunction, evidence-based protocols for the prevention and treatment of these disorders are still lacking. Several previous trials have attempted to prevent or treat clinical manifestation by modulation of the cholinergic system with acetylcholinesterase inhibitors, the results of which have been largely ambiguous at best. As the biochemical basis of postoperative cognitive dysfunction becomes more clearly defined, future research into therapeutics based on immune modulation and treatment of neuroinflammation may prove to be very promising.
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Affiliation(s)
- Matthew Umholtz
- a Department of Anesthesiology , Brandon Regional Hospital , Tampa , FL
| | - Nader D Nader
- b Anesthesiology and Surgery, University at Buffalo , Buffalo , NY.,c Pathology and Anatomical Sciences, University at Buffalo , Buffalo , NY , USA
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3
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MacRae K, Connolly K, Vella R, Fenning A. Epicatechin's cardiovascular protective effects are mediated via opioid receptors and nitric oxide. Eur J Nutr 2018; 58:515-527. [PMID: 29748816 DOI: 10.1007/s00394-018-1650-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 10/13/2017] [Indexed: 12/14/2022]
Abstract
PURPOSE Cardiovascular disease is the leading cause of mortality globally. Epicatechin has previously been shown to improve vascular responses and possess cardioprotective properties. However, the mechanisms underpinning these cardiotropic outcomes remain unknown. The aim of this study was to further identify epicatechin's mechanism of action in the cardiovasculature. METHODS The effects of epicatechin on isolated rat conduit arteries, resistance vessels and cardiac electrophysiology were investigated on resting tension and precontracted vessels and cardiac action potential parameters, both in the presence and in the absence of various antagonists. RESULTS At resting tension, epicatechin alone did not affect the vasoreactivity of either conduit or resistance vessels. In noradrenaline pre-contracted thoracic aortic arteries and potassium chloride pre-contracted mesenteric vessels, epicatechin (10-9-10-4 M) induced significant vasorelaxation. The addition of naloxone (10-5 M), NG-nitro-L-arginine methyl ester (10-5M), 4-aminopyridine (5 mM) and verapamil (10-5 M) attenuated epicatechin-mediated vasorelaxation. No change in epicatechin-mediated vasorelaxation was observed with the addition of atropine (10-5 M). Epicatechin significantly improved cardiac electrophysiology by reducing the resting membrane potential, action potential amplitude and force of contraction that was mitigated following the addition of naloxone (10-5 M). Epicatechin significantly decreased the action potential duration at 20, 50 and 90% duration and time to 90% relaxation of force that was unchanged following the addition of naloxone (10-5 M). CONCLUSIONS These findings suggest epicatechin's vascular responses and cardioprotective effects are mediated through opioid receptors, nitric oxide, potassium channel and calcium channel activation and highlight the importance of the endothelium/nitric oxide in epicatechin mediated vasorelaxation.
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Affiliation(s)
- Kirsty MacRae
- School of Health, Medical and Applied Sciences, CQUniversity, Building 81, North Rockhampton, QLD, 4702, Australia
| | - Kylie Connolly
- School of Health, Medical and Applied Sciences, CQUniversity, Building 81, North Rockhampton, QLD, 4702, Australia
| | - Rebecca Vella
- School of Health, Medical and Applied Sciences, CQUniversity, Building 81, North Rockhampton, QLD, 4702, Australia
| | - Andrew Fenning
- School of Health, Medical and Applied Sciences, CQUniversity, Building 81, North Rockhampton, QLD, 4702, Australia.
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4
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Maleki M, Hassanpour-Ezatti M, Navaeian M. Cross State-dependent Learning Interaction Between Scopolamine and Morphine in Mice: The Role of Dorsal Hippocampus. Basic Clin Neurosci 2017; 8:193-202. [PMID: 28781727 PMCID: PMC5535325 DOI: 10.18869/nirp.bcn.8.3.193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION The current study aimed at investigating the existence of the cross state-dependent learning between morphine and scopolamine (SCO) in mice by passive avoidance method, pointing to the role of CA1 area. METHODS The effects of pre-training SCO (0.75, 1.5, and 3 μg, Intra-CA1), or morphine (1, 3, and 6 mg/kg, intraperitoneal (i.p.) was evaluated on the retrieval of passive avoidance learning using step-down task in mice (n=10). Then, the effect of pretest administration of morphine (1.5, 3, and 6 mg/kg, i.p.) was examined on passive avoidance retrieval impairment induced by pre-training SCO (3 μg/mice, Intra-CA1). Next, the effect of pretest Intra-CA1 injection of scopolamine (0.75, 1.5, and 3 μg/mice) was evaluated on morphine (6 mg/kg, i.p.) pre-training deficits in this task in mice. RESULTS The pre-training Intra-CA1 injection of scopolamine (1.5 and 3 μg/mouse), or morphine (3 and 6 mg/kg, i.p.) impaired the avoidance memory retrieval when it was tested 24 hours later. Pretest injection of both drugs improved its pre-training impairing effects on mice memory. Moreover, the amnesia induced by the pre-training injections of scopolamine (3 μg/mice) was restored significantly (P<0.01) by pretest injections of morphine (3 and 6 mg/kg, i.p.). Similarly, pretest injection of scopolamine (3 μg/mice) restored amnesia induced by the pre-training injections of morphine (6 mg/kg, i.p.), significantly (P<0.01). CONCLUSION The current study findings indicated a cross state-dependent learning between SCO and morphine at CA1 level. Therefore, it seems that muscarinic and opioid receptors may act reciprocally on modulation of passive avoidance memory retrieval, at the level of dorsal hippocampus, in mice.
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Affiliation(s)
- Morteza Maleki
- Department of Biology, School of Basic Sciences, Shahed University, Tehran, Iran
| | | | - Majid Navaeian
- Department of Biology, Shahr Rey Branch, Islamic Azad University, Tehran, Iran
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5
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Harburg GC, Hall FS, Harrist AV, Sora I, Uhl GR, Eisch AJ. Knockout of the mu opioid receptor enhances the survival of adult-generated hippocampal granule cell neurons. Neuroscience 2006; 144:77-87. [PMID: 17055658 PMCID: PMC2230097 DOI: 10.1016/j.neuroscience.2006.09.018] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 08/30/2006] [Accepted: 09/05/2006] [Indexed: 01/01/2023]
Abstract
Recent evidence suggests that mu opioid receptors (MOR) are key regulators of hippocampal structure and function. For example, exogenous MOR agonists morphine and heroin negatively impact hippocampal function and decrease adult hippocampal neurogenesis. Here we explored the role of MOR in the birth and survival of hippocampal progenitor cells by examining adult neurogenesis in mice that lack MOR. Adult male mice lacking exon 1 of MOR were injected with the S phase marker bromodeoxyuridine (BrdU) and killed either 2 hours or 4 weeks later to evaluate proliferating and surviving BrdU-immunoreactive (IR) cells, respectively, in the adult hippocampal granule cell layer. Wild-type (WT), heterozygote, and homozygote mice did not differ in the number of BrdU-IR cells at a proliferation time point. However, 4 weeks after BrdU injection, heterozygote and homozygote mice had 57% and 54% more surviving BrdU-IR cells in the hippocampal granule cell layer as compared with WT mice. A decrease in apoptosis in the heterozygote and homozygote mice did not account for the difference in number of surviving BrdU-IR cells since there were no alterations in number of pyknotic, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive, or activated caspase 3-IR cells compared with WT. In concordance with the increased numbers of granule cells maturing into neurons, heterozygote and homozygote mice had larger hippocampal granule cell layers and increased numbers of granule cells. These findings indicate that MOR may play a role in regulating progenitor cell survival and more generally encourage further exploration of how MOR activation can influence hippocampal structure and function.
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Affiliation(s)
- Gwyndolen C. Harburg
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - F. Scott Hall
- Molecular Neurobiology Branch, NIDA-IRP, NIH/DHHS, Baltimore, Maryland
| | - Alexia V. Harrist
- University of Pennsylvania Medical School of Medicine, Philadelphia, PA
| | - Ichiro Sora
- Tohoku University Graduate School of Medicine, Department of Neuroscience, Sendai, Japan
| | - George R. Uhl
- Molecular Neurobiology Branch, NIDA-IRP, NIH/DHHS, Baltimore, Maryland
| | - Amelia J. Eisch
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
- Correspondence: A. J. Eisch, Department of Psychiatry, University of Texas, Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9070. Tel: (214) 648-5549; Fax: (214) 645-9549. E-mail:
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6
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Yanai J, Ben-Shaanan TL, Haimovitch H, Katz S, Kazma M. Mechanism-Based Approaches for the Reversal of Drug Neurobehavioral Teratogenicity. Ann N Y Acad Sci 2006; 1074:659-71. [PMID: 17105961 DOI: 10.1196/annals.1369.066] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Understanding the mechanism of neurobehavioral teratogenicity is the primary prerequisite for reversal of the defect. Progress in such studies can be best achieved if the investigation focuses on behaviors related to a specific brain region and innervation. Our model focused on teratogen-induced deficits in hippocampus-related eight-arm and Morris maze behaviors. Different "cholinergic" teratogens, mainly heroin, induced both pre- and postsynaptic hyperactivity in the hippocampal cholinergic innervation that terminated in desensitization of Protein Kinase C (PKC) isoforms to cholinergic receptor stimulation. Understanding this mechanism enabled its reversal with a pharmacological therapy-nicotine infusion. Studies by others provided similar findings by targeting the deficits respective to the model investigated. Consistently, destruction of the A10-septal dopaminergic pathways that downregulate the septohippocampal cholinergic innervation ameliorated maze performance. Grafting of embryonic differentiated cholinergic cells or neural progenitors similarly reversed the biochemical/molecular alterations and the resulting deficits. Reversal therapies offer a model for the understanding of neurobehavioral teratogenicity and, clinically, offer a model for potential treatment of these deficits. Whereas neural progenitor grafting appears to be the most effective treatment, pharmacological reversal with nicotine infusion seems to possess the most feasible and immediate therapy for neurobehavioral birth defects produced by various teratogens, including drugs. This is true even though the effect of pharmacological therapies is diffuse, affecting multiple areas of the brain. "Everybody is talking about the weather but nobody does anything about it." (Mark Twain).
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Affiliation(s)
- Joseph Yanai
- The Ross Laboratory for Studies in Neural Birth Defects, Department of Anatomy and Cell Biology, The Hebrew University-Hadassah Medical School, Box 12272, 91010 Jerusalem, Israel.
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Widmer H, Ferrigan L, Davies CH, Cobb SR. Evoked slow muscarinic acetylcholinergic synaptic potentials in rat hippocampal interneurons. Hippocampus 2006; 16:617-28. [PMID: 16770798 DOI: 10.1002/hipo.20191] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The hippocampus receives an extensive cholinergic input from the medial septal nucleus that ramifies throughout all layers and plays a pivotal modulatory role in cognitive function. Although the pharmacological effects of exogenous application of cholinergic agonists have been extensively studied in hippocampal neurons, much less is known about the effects of synaptically released acetylcholine (ACh). In this respect, most studies have focused on the cholinergic afferent input to pyramidal neurons that produces a characteristically slow depolarizing synaptic response mediated by activation of muscarinic ACh receptors (mAChRs). Here we report that cholinergic afferent stimulation also elicits atropine-sensitive synaptic potentials in hippocampal CA1 interneurons but, in contrast to synaptic responses in pyramidal neurons, these are highly diverse in waveform, although can still be classified into five distinct subtypes. The most common response type (i) 64% of cells) consisted of a slow sustained membrane potential depolarization. The other 36% of responses could be subdivided into responses comprising of (ii) a biphasic membrane potential change in which an initial slow hyperpolarization subsequently transforms into a slow depolarization (20%), (iii) a pure, slow hyperpolarization (13%), and (iv) an oscillatory response persisting for several seconds (2%). Interestingly, there were also interneurons totally insensitive to both synaptic and pharmacological cholinergic challenge. Morphological investigation of recorded cells revealed no obvious correlation between responsiveness to cholinergic afferent stimulation and dendritic and axonal arborization. The current study suggests that synaptic release of ACh results in a complex and differential mAChR-mediated modulation of cellular excitability within the hippocampal interneuron population.
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Affiliation(s)
- H Widmer
- Division of Neuroscience and Biomedical Systems, IBLS, University of Glasgow, Glasgow, United Kingdom
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8
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Abstract
Septo-hippocampal cholinergic fibres ramify extensively throughout the hippocampal formation to release acetylcholine upon a diverse range of muscarinic and nicotinic acetylcholine receptors that are differentially expressed by distinct populations of neurones. The resultant modulation of cellular excitability and synaptic transmission within hippocampal circuits underlies the ability of acetylcholine to influence the dynamic properties of the hippocampal network and results in the emergence of a range of stable oscillatory network states. Recent findings suggest a multitude of actions contribute to the oscillogenic properties of acetylcholine which are principally induced by activation of muscarinic receptors but also regulated through activation of nicotinic receptor subtypes.
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Affiliation(s)
- Stuart R Cobb
- Division of Neuroscience and Biomedical Systems, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
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9
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Tien LT, Fan LW, Sogawa C, Ma T, Loh HH, Ho IK. Changes in acetylcholinesterase activity and muscarinic receptor bindings in mu-opioid receptor knockout mice. ACTA ACUST UNITED AC 2004; 126:38-44. [PMID: 15207914 PMCID: PMC2923208 DOI: 10.1016/j.molbrainres.2004.03.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2004] [Indexed: 10/26/2022]
Abstract
Anatomical evidence indicates that cholinergic and opioidergic systems are co-localized and acting on the same neurons. However, the regulatory mechanisms between cholinergic and opioidergic system have not been well characterized. In the present study, we investigated whether there are compensatory changes of acetylcholinesterase activity and cholinergic receptors in mice lacking mu-opioid receptor gene. The acetylcholinesterase activity was determined by histochemistry assay. The cholinergic receptor binding was carried out by quantitative autoradiography using [3H]-quinuclidinyl benzilate (nonselective muscarinic receptors), N-[3H]-methylscopolamine (nonselective muscarinic receptors), [3H]-pirenzepine (M1 subtype muscarinic receptors) and [3H]-AF-DX384 (M2 subtype muscarinic receptors) in brain slices of wild-type and mu-opioid receptor knockout mice. The acetylcholinesterase activity of mu-opioid receptor knockout mice was higher than that of the wild-type in the striatal caudate putamen and nucleus accumbens, but not in the cortex and hippocampus areas. In addition, the bindings in N-[3H]-methylscopolamine and [3H]-AF-DX384 of mu-opioid receptor knockout mice were significantly lower when compared with that of the wild-type controls in the striatal caudate putamen and nucleus accumbens. However, there were no significant differences in bindings of [3H]-quinuclidinyl benzilate and [3H]-pirenzepine between mu-opioid receptor knockout and wild-type mice in the cortex, striatum and hippocampus. These data indicate that there are up-regulation of acetylcholinesterase activity and compensatory down-regulation of M2 muscarinic receptors in the striatal caudate putamen and nucleus accumbens of mu-opioid receptor knockout mice.
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Affiliation(s)
- Lu-Tai Tien
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4504, USA
| | - Lir-Wan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4504, USA
| | - Chiharu Sogawa
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4504, USA
| | - Tangeng Ma
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4504, USA
| | - Horance H. Loh
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Ing-Kang Ho
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4504, USA
- Corresponding author. Tel.: +1-601-984-1600; fax: +1-601-984-1637. (I.-K. Ho)
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Kaplan TJ, Skyers PR, Tabori NE, Drake CT, Milner TA. Ultrastructural evidence for mu-opioid modulation of cholinergic pathways in rat dentate gyrus. Brain Res 2004; 1019:28-38. [PMID: 15306235 DOI: 10.1016/j.brainres.2004.05.050] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2004] [Indexed: 11/30/2022]
Abstract
Within the rat hippocampal formation, cholinergic afferents and mu-opioid receptors (MORs) are involved in many crucial learning processes, including those associated with drug reward. Pharmacological data, and the overlapping distributions of cholinergic and mu-opioid systems, particularly in the dentate gyrus, suggest that MOR activation is a potential mechanism for endogenous opioid modulation of cholinergic activity. To date, anatomical evidence supporting this has not been reported. To delineate the relationship between cholinergic afferents and MOR-containing processes in the dentate gyrus, hippocampal sections were dually immunolabeled for vesicular acetylcholine transporter (VAChT) and MOR-1 and examined by electron microscopy. VAChT immunoreactivity was in unmyelinated axons and axon terminals, and was most often associated with small synaptic vesicles. MOR immunoreactivity was found in axons, axon terminals and, to a lesser extent, perikarya, which resembled GABAergic basket cells. Semi-quantitative ultrastructural analysis revealed that from 5% to 13% (depending on laminar location) of VAChT-immunoreactive (ir) presynaptic profiles contained MOR immunoreactivity. Additionally, 7% of VAChT-ir presynaptic profiles directly apposed MOR-ir axons and terminals, and there were almost no appositions to MOR-ir dendrites. These data suggest that opioids may directly and indirectly modulate acetylcholine release and/or reuptake. In the hilus and molecular layer, 4% of VAChT-ir terminals contacted dendritic shafts that were also contacted by MOR-ir terminals. This suggests that cholinergic afferents and MOR-containing afferents can converge on granule cell dendrites (which are restricted to the molecular layer) and on interneuron dendrites in the hilus. The results of this study provide ultrastructural evidence for direct and indirect modulation of cholinergic systems by mu-opioids in the hippocampal formation.
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Affiliation(s)
- Theodore J Kaplan
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Medical College of Cornell University, 411 East 69th Street, New York, NY 10021, USA
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Meilandt WJ, Barea-Rodriguez E, Harvey SAK, Martinez JL. Role of hippocampal CA3 mu-opioid receptors in spatial learning and memory. J Neurosci 2004; 24:2953-62. [PMID: 15044534 PMCID: PMC6729851 DOI: 10.1523/jneurosci.5569-03.2004] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The dorsal CA3 region of the hippocampus is unique in its connectivity, sensitivity to neurotoxic lesions, and its ability to encode and retrieve episodic memories. Computational models of the CA3 region predict that blocking mossy-fiber and/or perforant path activity to CA3 would cause impairments in learning and recall of spatial memory, respectively. Because the CA3 region contains micro-opioid receptors and receives inputs from the mossy-fiber and lateral perforant pathways, both of which contain and release opioid peptides, we tested the hypothesis that inactivating micro-opioid receptors in the CA3 region would cause spatial learning and memory impairments and retrieval deficits. In this study, male Sprague Dawley rats were trained in a Morris water maze after a single bilateral intrahippocampal injection of either saline or the selective and irreversible micro-opioid receptor antagonist beta-funaltrexamine (beta-FNA) into area CA3. We found that micro-opioid receptor binding decreased 24 hr after beta-FNA injection and returned to control levels 11 d after injection. Injections of beta-FNA into the CA3 region, but not into the ventricles, caused a significant impairment in the acquisition of spatial learning without causing sensory or motor deficits. New learning was not affected once micro-opioid receptor levels replenished (>11 d after injection). In pretrained animals, beta-FNA significantly impaired spatial memory retrieval and new (reversal) learning. These data are consistent with theoretical models of CA3 function and suggest that CA3 micro-opioid receptors play an important role in the acquisition and retrieval of spatial memory.
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Affiliation(s)
- William J Meilandt
- Cajal Neuroscience Institute, Department of Biology, University of Texas at San Antonio, San Antonio, Texas 78249-0662, USA.
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12
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Yaniv SP, Naor Z, Yanai J. Prenatal heroin exposure alters cholinergic receptor stimulated activation of the PKCβII and PKCγ isoforms. Brain Res Bull 2004; 63:339-49. [PMID: 15196660 DOI: 10.1016/j.brainresbull.2004.04.006] [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] [Received: 12/01/2003] [Revised: 03/22/2004] [Accepted: 04/11/2004] [Indexed: 11/15/2022]
Abstract
Prenatal exposure of mice to heroin (SC injection of 10mg/kg to the dams on gestational days 9-18) resulted at adulthood in behavioral deficits related to septohippocampal cholinergic innervation accompanied with both presynaptic and postsynaptic cholinergic hyperactivity; including an increase membrane PKC activity, and a desensitization of PKC to cholinergic input which were highly correlated with the behavioral performance and were reversed by cholinergic grafting. Therefore, we studied the receptor induced activation of the behaviorally relevant PKCgamma and PKCbetaII isoforms and the less behaviorally relevant PKCalpha isoform. Time course studies revealed peak translocation after 40 min incubation with carbachol for PKCgamma (110% increase from basal, i.e. no carbachol level, P < 0.01), 30 min for phosphorylated PKCbetaII (130%, P < 0.05) and 5 min for non-phosphorylated PKCbetaII (64%, P < 0.05) with no peak for alpha. Prenatal heroin abolished the translocation of PKCgamma and PKCbetaII while PKCalpha remained unaffected. A decrease occurred in basal phosphorylated membrane (-45%, P < 0.01) and cytosol-associated (-29%, P < 0.01) PKCbetaII, in membrane-associated non-phosphorylated PKCbetaII (-32%, P < 0.01) and PKCgamma (-25%, P < 0.01) and in cytosolic PKCalpha (-27%, P < 0.01), while membrane-associated PKCalpha was slightly increased (11%, P < 0.05). The results suggest that prenatal heroin disrupts cholinergic receptor induced PKC translocation and activation with the underlying mechanism of neuroteratogenicity potentially lying in the PKCgamma and PKCbetaII, while PKCalpha remains unaffected.
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Affiliation(s)
- Shiri P Yaniv
- The Ross Laboratory for Studies in Neural Birth Defects, Department of Anatomy and Cell Biology, The Hebrew University-Hadassah Medical School, Box 12272, Jerusalem 91120, Israel
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13
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Yoo JH, Lee SY, Loh HH, Ho IK, Jang CG. Altered emotional behaviors and the expression of 5-HT1A and M1 muscarinic receptors in ?-opioid receptor knockout mice. Synapse 2004; 54:72-82. [PMID: 15352132 DOI: 10.1002/syn.20067] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Anxiety and depression alterations have been reported in micro-opioid receptor knockout mice after exon 2 disruption. However, emotional behaviors, such as novelty and emergence responses have not been reported in micro-opioid receptor knockout mice due to the disruptions of exon 2 and 3. Here, we report that mu-opioid receptor knockout mice, with deletion of exon 2 and 3, display significant emotional behavior changes; they showed less anxiety in the elevated plus maze and emergence tests, reduced response to novel stimuli in the novelty test, and less depressive-like behavior in the forced-swim test. Analysis of the compensatory mechanism in mu-opioid receptor knockout mice revealed that the M1 mRNA levels were reduced in the cortex, caudate putamen, nucleus accumbens, and hippocampus, and that M1 receptor levels were reduced in the nucleus accumbens, CA1, and the dentate gyrus of the hippocampus, versus the wild-type. However, 5-HT1A receptor levels were significantly elevated in the cerebral cortex and in the hypothalamus of mu-opioid receptor knockout mice versus the wild-type. These aberrant emotional behavioral phenotypes are possibly related to M1 and 5-HT1A receptor alterations in the micro-opioid receptor knockout mice. Overall, our study suggests that micro-opioid receptor may play a role in the modification of emotional responses to novelty, anxiety, and depression.
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MESH Headings
- 8-Hydroxy-2-(di-n-propylamino)tetralin/pharmacokinetics
- Analysis of Variance
- Animals
- Behavior, Animal
- Brain/anatomy & histology
- Brain/diagnostic imaging
- Emotions/physiology
- Exploratory Behavior/physiology
- Gene Expression Regulation/physiology
- Immobilization
- In Situ Hybridization/methods
- Maze Learning/physiology
- Mice
- Mice, Knockout
- Muscarinic Antagonists/pharmacokinetics
- Pirenzepine/pharmacokinetics
- RNA, Messenger/metabolism
- Radioligand Assay/methods
- Radionuclide Imaging
- Reaction Time/genetics
- Receptor, Muscarinic M1/genetics
- Receptor, Muscarinic M1/metabolism
- Receptor, Serotonin, 5-HT1A/genetics
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptors, Opioid, mu/deficiency
- Receptors, Opioid, mu/genetics
- Serotonin Receptor Agonists/pharmacokinetics
- Swimming/physiology
- Time Factors
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Affiliation(s)
- Ji-Hoon Yoo
- Department of Pharmacology, College of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
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14
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Abstract
This paper is the twenty-fourth installment of the annual review of research concerning the opiate system. It summarizes papers published during 2001 that studied the behavioral effects of the opiate peptides and antagonists. The particular topics covered this year include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology(Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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15
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Abdollahi M, Safarhamidi H. Protection by nitric oxide of morphine-induced inhibition of rat submandibular gland function. Pharmacol Res 2002; 45:87-92. [PMID: 11846618 DOI: 10.1006/phrs.2001.0910] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of morphine, l -arginine (nitric oxide precursor) and l -NAME (nitric oxide synthesis inhibitor ) and their concurrent therapy on rat submandibular secretory function were studied. Pure submandibular saliva was collected intraorally by micro polyethylene cannula from anaesthetized rats using pilocarpine as secretagogue. Single intraperitoneal injection of morphine (6 mg kg(-1)) to rats induced significant (P< 0.01) inhibition of salivary flow rate (28%), total protein (12%) and calcium concentrations (27%). Sodium output was increased (23%, P< 0.01). Single intraperitoneal administration of l -arginine (100 mg kg(-1)) and l -NAME (10 mg kg(-1)) affected salivary gland function. Saliva flow rate was reduced by l -NAME (23%, P< 0.01). The total protein concentration of saliva was increased by l -arginine (21%, P< 0.05) and decreased by l -NAME (19%, P< 0.01). Calcium concentration of saliva was increased by l -arginine (25%, P< 0.01) and reduced by l -NAME (21%, P< 0.01). In combination treatment, l -arginine prevented (P< 0.01) morphine-induced reduction of flow rate while l -NAME potentiated it (P< 0.01). The secretion of total protein and calcium were influenced in a similar trend by concurrent therapy. l -NAME potentiated morphine-induced decrease of total protein and calcium concentrations (P< 0.01) while l -arginine restored (P< 0.01) them to levels close to control and morphine groups respectively. It is concluded that morphine inhibits salivary gland function and nitric oxide (NO) plays a positive role in this system. Also it is confirmed that morphine inhibitory effects on submandibular function are somewhat restored by l -arginine and expanded by l -NAME. The modulatory effect of the l -arginine/NO system on salivary gland function is suggested.
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Affiliation(s)
- Mohammad Abdollahi
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
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