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Piechal A, Jakimiuk A, Pyrzanowska J, Blecharz-Klin K, Joniec-Maciejak I, Wiercińska-Drapało A, Mirowska-Guzel D, Widy-Tyszkiewicz E. Long-term Administration of 3-Di-O-Tolylguanidine Modulates Spatial Learning and Memory in Rats and Causes Transition in the Concentration of Neurotransmitters in the Hippocampus, Prefrontal Cortex and Striatum. Neuroscience 2023; 510:129-146. [PMID: 36493909 DOI: 10.1016/j.neuroscience.2022.11.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 11/14/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022]
Abstract
The sigma-1 and sigma-2 (σ1 and σ2) receptors are found in high concentrations in the brain, and their altered expression leads to a variety of neuropsychiatric disorders. 3-di-tolylguanidine (DTG) stimulates the activity of both of these receptors. We assessed the effects of administering DTG to adult male Sprague Dawley rats on learning and memory consolidation processes and on the levels of neurotransmitters in selected brain structures. Spatial learning and memory were evaluated in the water maze test. The DTG was administered orally at daily doses of 3 mg/kg (DTG3), 10 mg/kg (DTG10) or 30 mg/kg (DTG30) for 10 weeks before and during the water-maze test. After completion of the experiment, the concentration of monoamines and their metabolites as well as amino acids in structures involved in cognitive performance - the hippocampus, prefrontal cortex, and striatum - were determined using high performance liquid chromatography (HPLC). The DTG10 group showed an improvement in memory processes related to the "new" platform location, whereas the DTG30 group was worse at finding the "old" platform location. Since the administration of DTG led to differences in dopaminergic transmission, it was assumed to influence memory processes in this way. Changes in histidine, serine, alanine, taurine, and glutamic acid levels in selected structures of the brains of rats with memory impairment were also observed. We conclude that long-term administration of DTG modulates spatial learning and memory in rats and changes the concentrations of neurotransmitters in the hippocampus, prefrontal cortex, and striatum..
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Affiliation(s)
- Agnieszka Piechal
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, Banacha 1B, 02-097 Warsaw, Poland
| | - Alicja Jakimiuk
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, Banacha 1B, 02-097 Warsaw, Poland
| | - Justyna Pyrzanowska
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, Banacha 1B, 02-097 Warsaw, Poland.
| | - Kamilla Blecharz-Klin
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, Banacha 1B, 02-097 Warsaw, Poland
| | - Ilona Joniec-Maciejak
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, Banacha 1B, 02-097 Warsaw, Poland
| | - Alicja Wiercińska-Drapało
- Department of Infectious and Tropical Diseases and Hepatology, Medical University of Warsaw, Wolska 37, 01-201 Warsaw, Poland
| | - Dagmara Mirowska-Guzel
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, Banacha 1B, 02-097 Warsaw, Poland
| | - Ewa Widy-Tyszkiewicz
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, Banacha 1B, 02-097 Warsaw, Poland
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Brockway DF, Crowley NA. Turning the 'Tides on Neuropsychiatric Diseases: The Role of Peptides in the Prefrontal Cortex. Front Behav Neurosci 2020; 14:588400. [PMID: 33192369 PMCID: PMC7606924 DOI: 10.3389/fnbeh.2020.588400] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/09/2020] [Indexed: 12/15/2022] Open
Abstract
Recent advancements in technology have enabled researchers to probe the brain with the greater region, cell, and receptor specificity. These developments have allowed for a more thorough understanding of how regulation of the neurophysiology within a region is essential for maintaining healthy brain function. Stress has been shown to alter the prefrontal cortex (PFC) functioning, and evidence links functional impairments in PFC brain activity with neuropsychiatric disorders. Moreover, a growing body of literature highlights the importance of neuropeptides in the PFC to modulate neural signaling and to influence behavior. The converging evidence outlined in this review indicates that neuropeptides in the PFC are specifically impacted by stress, and are found to be dysregulated in numerous stress-related neuropsychiatric disorders including substance use disorder, major depressive disorder (MDD), posttraumatic stress disorder, and schizophrenia. This review explores how neuropeptides in the PFC function to regulate the neural activity, and how genetic and environmental factors, such as stress, lead to dysregulation in neuropeptide systems, which may ultimately contribute to the pathology of neuropsychiatric diseases.
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Affiliation(s)
- Dakota F Brockway
- Neuroscience Curriculum, Pennsylvania State University, University Park, PA, United States
| | - Nicole A Crowley
- Neuroscience Curriculum, Pennsylvania State University, University Park, PA, United States.,The Department of Biology, Pennsylvania State University, University Park, PA, United States
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Peptide YY Causes Apathy-Like Behavior via the Dopamine D2 Receptor in Repeated Water-Immersed Mice. Mol Neurobiol 2018; 55:7555-7566. [PMID: 29429048 PMCID: PMC6096978 DOI: 10.1007/s12035-018-0931-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 01/24/2018] [Indexed: 12/21/2022]
Abstract
Apathy is observed across several neurological and psychiatric conditions; however, its pathogenesis remains unclear. We clarified the involvement of brain–gut signaling in the disruption of goal-directed behavior. Male C57BL/6J mice were exposed to water immersion (WI) stress for 3 days. Food intake and nesting behavior were measured as indexes of motivation. Repeated WI caused decrease in food intake and nesting behavior. Plasma levels of peptide YY (PYY), IL-6, and ratio of dopamine metabolites in the striatum were significantly elevated after WI. PYY and IL-6 administration significantly decreased nesting behavior. The reductions in feeding and nesting behavior were blocked by PYY receptor (Y2R) antagonist or dopamine agonist. The ameliorative effect of the Y2R antagonist was diminished by the dopamine D2 receptor (D2R) antagonist. The reduction in goal-directed behavior is associated with dysfunction of D2R signaling via increased peripheral PYY, suggesting that PYY antagonism is a novel candidate for decline of motivation in several depressive diseases.
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Robinson SL, Thiele TE. The Role of Neuropeptide Y (NPY) in Alcohol and Drug Abuse Disorders. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2017; 136:177-197. [PMID: 29056151 DOI: 10.1016/bs.irn.2017.06.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neuropeptide Y (NPY) is a neuromodulator that is widely expressed throughout the central nervous system (CNS) and which is cosecreted with classic neurotransmitters including GABA and glutamate. There is a long history of research implicating a role for NPY in modulating neurobiological responses to alcohol (ethanol) as well as other drugs of abuse. Both ethanol exposure and withdrawal from chronic ethanol have been shown to produce changes in NPY and NPY receptor protein levels and mRNA expression in the CNS. Importantly, manipulations of NPY Y1 and Y2 receptor signaling have been shown to alter ethanol consumption and self-administration in a brain region-specific manner, with Y1 receptor activation and Y2 receptor blockade in regions of the extended amygdala promoting robust reductions of ethanol intake. Similar observations have been made in studies examining neurobiological responses to nicotine, psychostimulants, and opioids. When taken together with observations of potential genetic linkage between the NPY system and the human alcohol abuse disorders, NPY represents a promising target for treating problematic alcohol and drug use, and in protecting individuals from relapse during abstinence.
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Affiliation(s)
- Stacey L Robinson
- University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Todd E Thiele
- University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.
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Kotagale NR, Upadhya M, Hadole PN, Kokare DM, Taksande BG. Involvement of hypothalamic neuropeptide Y in pentazocine induced suppression of food intake in rats. Neuropeptides 2014; 48:133-41. [PMID: 24656792 DOI: 10.1016/j.npep.2014.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 01/29/2014] [Accepted: 02/24/2014] [Indexed: 10/25/2022]
Abstract
The potent orexigenic peptide neuropeptide Y (NPY) has been considered as a possible endogenous ligand for a subpopulation of sigma receptors (SigR). However, their mutual interaction with reference to feeding behavior remains poorly understood. In the present study, we explored the possible interaction between sigma1 receptors (Sig1R) agonist, pentazocine, and NPY on food intake in satiated rats. While pentazocine dose-dependently reduced the food intake, NPY significantly increased it at 2, 4 and 6h post injection time points. In combination studies, pretreatment with NPY (0.1 nmol/rat, intra-PVN) normalized the inhibitory effect of pentazocine (60 μg/rat, intra-PVN) on food intake. Similarly, pre-treatment with pentazocine (30 μg/rat, intra-PVN) significantly antagonized the orexigenic effect of NPY (0.5 and 1.0 nmol/rat, intra-PVN). Moreover, pentazocine treatment decreased NPY immunoreactivity in arcuate (ARC), paraventricular (PVN), dorsomedial (DMH) and ventromedial (VMH) nuclei of hypothalamus. However, no change was observed in lateral hypothalamus (LH). Study implicates the reduced NPY immunoreactivity for the anorectic effect observed following pentazocine injections. Therefore, the concomitant activation of the NPYergic system along with the Sig1R agonist treatment may serve a useful purpose in the management of the unwanted side effects related to energy homeostasis.
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Affiliation(s)
- Nandkishor R Kotagale
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur 441 002, MS, India
| | - Manoj Upadhya
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur 441 002, MS, India; Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University Campus, Nagpur 440 033, India
| | - Pravin N Hadole
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur 441 002, MS, India
| | - Dadasaheb M Kokare
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University Campus, Nagpur 440 033, India
| | - Brijesh G Taksande
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur 441 002, MS, India.
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Meurs A, Clinckers R, Ebinger G, Michotte Y, Smolders I. Sigma 1 receptor-mediated increase in hippocampal extracellular dopamine contributes to the mechanism of the anticonvulsant action of neuropeptide Y. Eur J Neurosci 2007; 26:3079-92. [PMID: 18005069 DOI: 10.1111/j.1460-9568.2007.05911.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The potent anticonvulsant properties of neuropeptide Y (NPY) are generally attributed to a Y2 receptor-mediated inhibition of glutamatergic synaptic transmission. Independent studies have shown that NPY increases brain dopamine content, possibly via interaction with sigma 1 receptors. Recently, we showed that increased extracellular hippocampal dopamine attenuates pilocarpine-induced limbic seizures via activation of hippocampal D2 receptors. Our aim in this study was to elucidate the role of increased hippocampal dopamine in the mechanism of the anticonvulsant action of NPY and to investigate the involvement of Y2 and sigma 1 receptors in this process. Limbic seizures were evoked in freely moving rats by intrahippocampal administration of pilocarpine via a microdialysis probe. NPY was administered intracerebroventricularly, intrahippocampally via the microdialysis probe, or coadministered intrahippocampally with the D2 receptor antagonist remoxipride, the Y2 receptor antagonist BIIE0246 or the sigma 1 receptor antagonist BD1047. Changes in hippocampal extracellular dopamine were monitored, and behavioural changes indicative of seizure activity were scored. Intracerebroventricular (10 nmol/3 microL) and intrahippocampal (20-50 microm) NPY administration increased hippocampal dopamine and attenuated pilocarpine-induced seizures. Hippocampal D2 receptor blockade (4 microm remoxipride) reversed the anticonvulsant effect of NPY. Y2 receptor blockade (1 microm BIIE0246) reversed the anticonvulsant effect of NPY but did not prevent NPY-induced increases in hippocampal dopamine. Sigma 1 receptor blockade (10 microm BD1047) abolished NPY-induced increases in hippocampal dopamine and reversed the anticonvulsant effect of NPY. Our results indicate that NPY-induced increases in hippocampal dopamine are mediated via sigma 1 receptors and contribute to the anticonvulsant effect of NPY via increased activation of hippocampal D2 receptors. This novel mechanism of anticonvulsant action of NPY is separate from, and may be complementary to, the well established Y2 receptor-mediated inhibition of hippocampal excitability.
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Affiliation(s)
- Alfred Meurs
- Department of Neurology, U. Z. Brussel, Laarbeeklaan 101,1090 Brussels, Belgium
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Werling LL, Lauterbach EC, Calef U. Dextromethorphan as a Potential Neuroprotective Agent With Unique Mechanisms of Action. Neurologist 2007; 13:272-93. [PMID: 17848867 DOI: 10.1097/nrl.0b013e3180f60bd8] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Dextromethorphan (DM) is a widely-used antitussive. DM's complex central nervous system (CNS) pharmacology became of interest when it was discovered to be neuroprotective due to its low-affinity, uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonism. REVIEW SUMMARY Mounting preclinical evidence has proven that DM has important neuroprotective properties in various CNS injury models, including focal and global ischemia, seizure, and traumatic brain injury paradigms. Many of these protective actions seem functionally related to its inhibitory effects on glutamate-induced neurotoxicity via NMDA receptor antagonist, sigma-1 receptor agonist, and voltage-gated calcium channel antagonist actions. DM's protection of dopamine neurons in parkinsonian models may be due to inhibition of neurodegenerative inflammatory responses. Clinical findings are limited, with preliminary evidence indicating that DM protects against neuronal damage. Negative findings seem to relate to attainment of inadequate DM brain concentrations. Small studies have shown some promise for treatment of perioperative brain injury, amyotrophic lateral sclerosis, and symptoms of methotrexate neurotoxicity. DM safety/tolerability trials in stroke, neurosurgery, and amyotrophic lateral sclerosis patients demonstrated a favorable safety profile. DM's limited clinical benefit is proposed to be associated with its rapid metabolism to dextrorphan, which restricts its central bioavailability and therapeutic utility. Systemic concentrations of DM can be increased via coadministration of low-dose quinidine (Q), which reversibly inhibits its first-pass elimination. Potential drug interactions with DM/Q are discussed. CONCLUSIONS Given the compelling preclinical evidence for neuroprotective properties of DM, initial clinical neuroprotective findings, and clinical demonstrations that the DM/Q combination is well tolerated, this strategy may hold promise for the treatment of various acute and degenerative neurologic disorders.
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Affiliation(s)
- Linda L Werling
- The Institute for Biomedical Sciences, The George Washington University Medical Center, Washington, DC, USA
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Waterhouse RN, Chang RC, Zhao J, Carambot PE. In vivo evaluation in rats of [(18)F]1-(2-fluoroethyl)-4-[(4-cyanophenoxy)methyl]piperidine as a potential radiotracer for PET assessment of CNS sigma-1 receptors. Nucl Med Biol 2006; 33:211-5. [PMID: 16546675 DOI: 10.1016/j.nucmedbio.2005.10.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 10/19/2005] [Accepted: 10/19/2005] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Sigma-1 receptors are expressed throughout the mammalian central nervous system (CNS) and are implicated in several psychiatric disorders, including schizophrenia and depression. We have recently evaluated the high-affinity (K(D)=0.5+/-0.2 nM, log P=2.9) sigma-1 receptor radiotracer [(18)F]1-(3-fluoropropyl)-4-(4-cyanophenoxymethyl)piperidine, [(18)F]FPS, in humans. In contrast to appropriate kinetics exhibited in baboon brain, in the human CNS, [(18)F]FPS does not reach pseudoequilibrium by 4 h, supporting the development of a lower-affinity tracer [Waterhouse RN, Nobler MS, Chang RC, Zhou Y, Morales O, Kuwabara H, et al. First evaluation of the sigma-1 receptor radioligand [(18)F]1-3-fluoropropyl-4-((4-cyanophenoxy)-methyl)piperidine ([(18)F]FPS) in healthy humans. Neuroreceptor Mapping 2004, July 15-18th, Vancouver, BC Canada 2004]. We describe herein the in vivo evaluation in rats of [(18)F]1-(2-fluoroethyl)-4-[(4-cyanophenoxy)methyl]piperidine ([(18)F]SFE) (K(D)=5 nM, log P=2.4), a structurally similar, lower-affinity sigma-1 receptor radioligand. METHODS [(18)F]SFE was synthesized (n=4) as previously described in good yield (54+/-6% EOB), high specific activity (2.1+/-0.6 Ci/micromol EOS) and radiochemical purity (98+/-1%) and evaluated in awake adult male rats. RESULTS Similar to [(18)F]FPS, regional brain radioactivity concentrations [percentage of injected dose per gram of tissue (%ID/g), 15 min] for [(18)F]SFE were highest in occipital cortex (1.86+/-0.06 %ID/g) and frontal cortex (1.76+/-0.38 %ID/g), and lowest in the hippocampus (1.01+/-0.02%ID/g). Unlike [(18)F]FPS, [(18)F]SFE cleared from the brain with approximately 40% reduction in peak activity over a 90-min period. Metabolite analysis (1 h) revealed that [(18)F]SFE was largely intact in the brain. Blocking studies showed a large degree (>80%) of saturable binding for [(18)F]SFE in discrete brain regions. CONCLUSIONS We conclude that [(18)F]SFE exhibits excellent characteristics in vivo and may provide a superior PET radiotracer for human studies due to its faster CNS clearance compared to [(18)F]FPS.
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Rosse RB, Deutsch SI. The “Yoking” of glutamatergic brain mechanisms involved in controlling brain neuronal excitability and psychosis to brain mechanisms involved in appetite regulation: a new hypothesis on the origin of psychosis. Med Hypotheses 2004; 62:406-12. [PMID: 14975512 DOI: 10.1016/j.mehy.2003.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2003] [Accepted: 11/02/2003] [Indexed: 10/26/2022]
Abstract
The authors speculate that the human primate evolved psychosis generating brain mechanisms in the service of certain feeding behaviors (i.e., appetite, foraging) during the course of evolution. Furthermore, these "psychosis generating brain mechanisms" may have grown directly out of brain mechanisms servicing appetite, of which neuropeptide Y (NPY) played an important role. A case is made for an NPY contribution to the pathophysiology of psychosis. We hypothesize that the psychomimetic effects of NPY extend to supporting certain "psychomotor" functions that might have been useful for obtaining food resources in "stressful environments" (potentially food resource rich/predator-competitor dangerous). The "psychomotor" functions proposed include helping the evolving ancestral human primate overcome behavioral inhibitions and fears related to venturing into "stressful environments" (potentially food resource rich/predator-competitor dangerous) after their home ranges had been stripped of resources, by providing feelings of decreased anxiety (anxiolysis), infatigability, and, perhaps, even grandiose delusions of physical ability and supernatural supports. We further speculate that it is this NPY mechanism that in part becomes dysregulated in idiopathic psychotic disorders such as schizophrenia. The NPY connection with psychosis could theoretically account for the possible associations between weight changes and antipsychotic response (e.g. [Acta Psychiatr. Scand. 100 (1999) 3] reported by others and body mass index and cocaine-induced psychosis by our group (i.e. [Israel J. Psychiatr. (2004), in submission]).
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Affiliation(s)
- Richard B Rosse
- Department of Veterans Affairs Medical Center, Mental Health Service Line/116A, VISN 5, 50 Irving Street, NW, Washington, DC 20422, USA
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Gannon CJ, Malone DL, Napolitano LM. Reduction of IL-10 and nitric oxide synthesis by SR31747A (sigma ligand) in RAW murine macrophages. Surg Infect (Larchmt) 2003; 2:267-72; discussion 273. [PMID: 12593702 DOI: 10.1089/10962960152813304] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND There are several subtypes of sigma receptor, one of which is found throughout the immune system. SR31747A is a unique sigma ligand that possesses potent immune modulatory properties. Previous in vivo studies have documented that administration of SR31747A in murine models of sepsis resulted in decreased proinflammatory (IL-1, IL-6, TNF-alpha) and increased anti-inflammatory (IL-10) response (serum, splenocyte). Studies regarding the effect of this sigma ligand on purified macrophages are lacking. We therefore sought to investigate the effect of SR31747A in LPS-stimulated murine macrophages (RAW 264.7). METHODS RAW cells were incubated at 2.5 x 10(5) cells/well; controls were incubated with media alone, experimental groups contained LPS (0.01 microg) and SR31747A (1 nM, 10 nM, 100 nM, 1 microM, 10 microM). Supernatant and cells were harvested at 24 and 48 h. Concentrations of nitric oxide (Greiss reaction) and IL-10 were determined in the supernatant; cellular IL-10 mRNA was assessed. RESULTS SR31747A induced a dose-dependent reduction in NO and IL-10 protein release in LPS-stimulated murine macrophages. The decrease in IL-10 protein synthesis was paralleled by a significant dose-dependent reduction in IL-10 mRNA. CONCLUSION SR31747A is a novel immunomodulator that down regulates nitric oxide and IL-10 protein and mRNA expression. This in vitro reduction of IL-10 protein and mRNA expression is in contrast to previous in vivo murine studies. These data suggest that peripheral macrophages are not the source of the increased anti-inflammatory (IL-10) response induced by SR31747A.
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Affiliation(s)
- C J Gannon
- Department of Surgery, University of Maryland School of Medicine, 10 North Greene Street, Baltimore, MD 21201, USA
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Nuwayhid SJ, Werling LL. Sigma1 receptor agonist-mediated regulation of N-methyl-D-aspartate-stimulated [3H]dopamine release is dependent upon protein kinase C. J Pharmacol Exp Ther 2003; 304:364-9. [PMID: 12490613 DOI: 10.1124/jpet.102.043398] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have previously shown that sigma1 receptor agonists inhibit N-methyl-D-aspartate (NMDA)-stimulated [3H]dopamine from slices of rat striatum in a concentration-related manner and that the inhibition is reversed by sigma1 receptor-selective and nonsubtype-selective sigma receptor antagonists. Based on previous evidence from our laboratory as well as other laboratories, we hypothesized that sigma1 receptors might use a protein kinase C (PKC) signaling pathway to modulate stimulated dopamine release. We tested several inhibitors of PKC isozymes, as well as a phospholipase C inhibitor for their effects on sigma1 receptor agonist-mediated regulation of [3H]dopamine release. Although none of the inhibitors tested affected the ability of NMDA to stimulate [3H]dopamine release, they all abolished regulation by the sigma1 receptor agonist (+)-pentazocine in a concentration-related manner. We also found that prior exposure to 1 microM phorbol 2-myristate 13-acetate for 30 min abolished regulation by (+)-pentazocine. We concluded that an intact PKC system was required for sigma1 agonist-mediated regulation of NMDA-stimulated [3H]dopamine release from rat striatal slices. Based on the pharmacological profile of the PKC inhibitors tested, as well as reports in the literature on PKC
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Affiliation(s)
- Samer J Nuwayhid
- Department of Pharmacology, The George Washington University Medical Center, Washington, DC 20037, USA
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Hong W, Werling L. Lack of effects by sigma ligands on neuropeptide Y-induced G-protein activation in rat hippocampus and cerebellum. Brain Res 2001; 901:208-18. [PMID: 11368969 DOI: 10.1016/s0006-8993(01)02348-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
It has been suggested that neuropeptide Y (NPY) and sigma (sigma) receptor ligands may share a putative NPY/sigma receptor in rat brain. To study whether NPY and sigma receptor ligands have an inverse agonism at this putative NPY/sigma receptor, we measured their effects on G-protein activity in rat brain. Using [35S]GTPgammaS autoradiography, we found that NPY-induced G-protein activation exhibited a discrete distribution pattern in rat brain. G-protein activation in superficial cortical layers and hippocampal CA1-3 region was mainly attributed to Y1 and Y2 receptors, respectively. In the presence of 10 microM sigma-receptor agonist BD737 or 10 microM sigma-receptor antagonist haloperidol, the distribution and density of [35S]GTPgammaS binding stimulated by 10 nM NPY was not significantly altered. In rat cerebellar membranes, NPY stimulated high-affinity GTPase activity in a dose-related manner, with maximal effects of 29% increase over basal level seen at 500 nM. This NPY-elicited GTPase activity was not significantly affected by micromolar concentrations of the sigma-receptor antagonists Dup734 or haloperidol. Since no significant effects by sigma-receptor ligands on NPY-induced G-protein activation were observed, we did not see an inverse agonism of NPY and sigma-receptor ligands at the putative NPY/sigma receptor measured at the level of G-protein activation, suggesting that sigma receptors and NPY receptors do not represent a common population in rat hippocampus and cerebellum. It is also suggested that G-protein activation is not a convergent point for the signal transduction mechanisms of NPY receptors and sigma receptors.
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Affiliation(s)
- W Hong
- Neuroscience Program, The George Washington University Medical Center, Washington, DC 20037, USA
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Ault DT, Werling LL. SH-SY5Y cells as a model for sigma receptor regulation of potassium-stimulated dopamine release. Brain Res 2000; 877:354-60. [PMID: 10986350 DOI: 10.1016/s0006-8993(00)02722-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Previous studies in our laboratory using rat brain tissue have shown that neuropeptide Y (NPY) can enhance NMDA- and potassium-stimulated dopamine release from various brain regions and that this enhancement is reversed by sigma (sigma) receptor antagonists. In the current study, we sought to determine whether SH-SY5Y cells are suitable for investigating sigma receptor effects and whether any sigma receptors present are of the subtype responsive to NPY. We compare mechanisms by which the prototypical sigma receptor agonist (+)-pentazocine, and the proposed endogenous sigma receptor ligand NPY regulate potassium-stimulated [(3)H]dopamine release from SH-SY5Y cells. Both (+)-pentazocine and NPY inhibit potassium-stimulated [(3)H]dopamine release. Unlike our studies in rat brain tissue, the effect of NPY on [(3)H]dopamine release is not reversed by sigma receptor antagonists. SH-SY5Y cells appear to be an appropriate model to study the regulation of dopamine release by sigma receptors or by NPY receptors, but this population is not identical to that population identified in brain slices.
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Affiliation(s)
- D T Ault
- Neuroscience Program, The George Washington University Medical Center, 2300 I St. NW, Washington, DC 20037, USA
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Jiménez Vasquez PA, Salmi P, Ahlenius S, Mathé AA. Neuropeptide Y in brains of the Flinders Sensitive Line rat, a model of depression. Effects of electroconvulsive stimuli and d-amphetamine on peptide concentrations and locomotion. Behav Brain Res 2000; 111:115-23. [PMID: 10840138 DOI: 10.1016/s0166-4328(00)00142-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neuropeptide Y (NPY), has been implicated in the pathophysiology of depression and the mechanisms of action of electroconvulsive treatment (ECT). In this series of experiments, we explored whether there are differences between Flinders Sensitive Line (FSL) rats, an animal model of depression, and controls, Flinders Resistant Line (FRL) in (1) baseline brain NPY-LI concentrations, (2) effects of ECS on locomotion and brain neuropeptides, (3) amphetamine effects on behavior, and (4) effects of ECS pretreatment on subsequent effects of amphetamine on behavior. Both strains were divided into two groups, receiving eight ECS or ShamECS. Twenty-four hours after the last session, animals were habituated in activity boxes for 45 min before given d-amphetamine (1.5 mg.kg(-1), subcutaneously) or vehicle. Locomotor activity was then recorded for an additional 45 min. Twenty-four hours later, rats were sacrificed by microwave irradiation, the brains dissected into frontal cortex, occipital cortex, hippocampus, hypothalamus and striatum, and the neuropeptides extracted and measured by radioimmunoassay. No differences between FSL and FRL rats in baseline locomotor activity were found. FSL compared to FRL animals showed a significantly larger locomotion increase following saline and a significantly smaller increase following amphetamine. ECS pretreatment significantly decreased the saline effects on locomotion in the FSL and the amphetamine effects in the FRL rats. 'Baseline' NPY-like immunoreactivity (LI) concentrations were lower in the hippocampus of the 'depressed' rats. ECS increased NPY-LI in frontal cortex, occipital cortex and hippocampus of both strains. The hippocampal NPY-LI increase was significantly larger in the FSL compared to FRL animals.
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Affiliation(s)
- P A Jiménez Vasquez
- Department of Psychiatry, Institution of Clinical Neuroscience, St. Göran's Hospital, Karolinska Institutet, S-112 81, Stockholm, Sweden
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Dumont Y, Jacques D, St-Pierre JA, Tong Y, Parker R, Herzog H, Quirion R. Chapter IX Neuropeptide Y, peptide YY and pancreatic polypeptide receptor proteins and mRNAs in mammalian brains. HANDBOOK OF CHEMICAL NEUROANATOMY 2000. [DOI: 10.1016/s0924-8196(00)80011-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Ault DT, Werling LL. Phencyclidine and dizocilpine modulate dopamine release from rat nucleus accumbens via sigma receptors. Eur J Pharmacol 1999; 386:145-53. [PMID: 10618464 DOI: 10.1016/s0014-2999(99)00769-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phencyclidine (PCP) binds to many sites in brain, including PCP receptors located within the N-methyl-D-aspartate (NMDA) receptor-operated cation channel and sigma (sigma) receptors. In this study, we compare mechanisms by which PCP, dizocilpine (MK-801), the prototypical sigma receptor agonist (+)-pentazocine, and the proposed endogenous sigma receptor ligand neuropeptide Y regulate potassium (K(+))-stimulated [3H]dopamine release from slices of rat nucleus accumbens. (+)-Pentazocine inhibits K(+)-stimulated [3H]dopamine release, and neuropeptide Y enhances it. Both effects are blocked by sigma(1) and neuropeptide Y receptor antagonists, suggesting possible inverse agonism at a subpopulation of sigma/neuropeptide Y receptors. In contrast, PCP and MK-801 both enhance K(+)-stimulated [3H]dopamine release via sigma(1) and sigma(2) receptor subtypes, as demonstrated by antagonist sensitivity. Regulation of release by both (+)-pentazocine and neuropeptide Y persists in the presence of tetrodotoxin suggests that the sigma/neuropeptide Y receptors mediating the modulation are located presynaptically on dopaminergic nerve terminals, but tetrodotoxin eliminates regulation by PCP and MK-801, suggesting that receptors mediating their effects are located upstream from dopaminergic nerve terminals.
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Affiliation(s)
- D T Ault
- Neuroscience Program, The George Washington University Medical Center, Washington, DC 20037, USA
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