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Yan X, He W, Pan S. Amphetamine-induced neurite injury in PC12 cells through inhibiting GAP-43 pathway. Neurotoxicology 2022; 93:103-111. [PMID: 36150536 DOI: 10.1016/j.neuro.2022.09.004] [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: 02/10/2022] [Revised: 09/17/2022] [Accepted: 09/18/2022] [Indexed: 10/14/2022]
Abstract
Amphetamine (AMPH) causes the degeneration of dopamine terminals in the central nervous system. The mechanisms for this damage are unclear. We found AMPH reduced level of GAP-43 in the striatum of rats that receives rich dopaminergic terminals. Using PC12 cells as dopaminergic neuronal models, we further found that AMPH inhibited GAP-43 and GAP-43 phosphorylation in PC12 cells. The reduced GAP-43 was correlated with neurite injury of PC12 cells. The PKCβ1, an upstream molecule of GAP-43, was also inhibited by AMPH. Phorbol 12-myristate 13-acetate (PMA) as a specific activator of PKC increased levels of PKCβ1 and GAP-43, and efficiently prevented neurite degeneration of PC12 cells induced by AMPH. On the other side, enzastuarin, an inhibitor of PKC, decreased levels of PKCβ1 and GAP-43, and caused neurite injury of PC12 cells. Together, our results suggest that AMPH induces neurite injury in PC12 cells through inhibiting PKCβ1/GAP-43 pathway.
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Affiliation(s)
- Xinyu Yan
- Department of Anatomy, Medical College of Jinan University, Guangzhou, Guangdong Province, China; Department of Ultrasound, Yangxin People's Hospital, Yangxin, Hubei Province, China
| | - Wenji He
- Department of Anatomy, Medical College of Jinan University, Guangzhou, Guangdong Province, China; Department of Anatomy, Gannan Medical University, Ganzhou, Jiangxi Province, China
| | - Sanqiang Pan
- Department of Anatomy, Medical College of Jinan University, Guangzhou, Guangdong Province, China.
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Chen SC, Chen H, Yu SJ, Chen YH, Wang Y. Alleviation of Methamphetamine Sensitization by Partially Lesioning Dopaminergic Terminals with 6-Hydroxydopamine in Nucleus Accumbens. Cell Transplant 2021; 30:9636897211052300. [PMID: 34743572 PMCID: PMC8579363 DOI: 10.1177/09636897211052300] [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] [Indexed: 11/29/2022] Open
Abstract
Amphetamine-type stimulants have become important and popular abused drugs worldwide. Methamphetamine (Meth) sensitization, characterized by a progressive increase in behavioral responses after repeated administration, has been reported in rodents and patients. This behavioral effect has been used as a laboratory model to study drug addiction and schizophrenia. The mesolimbic dopaminergic pathway plays a significant role in the development of Meth behavioral sensitization. Previous studies have reported that the ablation of nucleus accumbens (NAc) by electrolytic or thermal lesioning attenuates addictive behavior to opioids in animals. However, these studies were only conducted in opioid addictive rodents. Furthermore, these ablation procedures also damaged the non-dopaminergic neurons and fibers passing through the NAc. The purpose of this study was to examine the therapeutic effect of NAc lesioning by a selective dopaminergic toxin in Meth-sensitized animals. Adult mice received repeated administration of Meth for 7 days. Open-field locomotor activity and stereotype behavior were significantly increased after Meth treatment, suggesting behavior sensitization. A partial lesion of dopaminergic terminals was made through stereotaxic administration of dopaminergic toxin 6-hydroxydopamine (6-OHDA) to the NAc in the Meth -sensitized mice. Meth behavioral sensitization was significantly antagonized after the lesioning. Brain tissue was collected for qRT-PCR analysis. Repeated administration of Meth increased the expression of tyrosine hydroxylase (TH), BDNF, and Shati, a marker for Meth sensitization, in the NAc. Treatment with 6-OHDA significantly antagonized the upregulation of TH and Shati. Taken together, these data suggest that local administration of 6-OHDA mitigated Meth sensitization in chronic Meth-treated animals. Our data support a new surgical treatment strategy for Meth abuse.
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Affiliation(s)
- Shu-Chun Chen
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan.,Graduate Institute of Applied Science and Engineering, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Hsi Chen
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Seong-Jin Yu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Yun-Hsiang Chen
- Department of Life Science, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Yun Wang
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
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Zhang K, Fan Z, Wang Y, Faraone SV, Yang L, Chang S. Genetic analysis for cognitive flexibility in the trail-making test in attention deficit hyperactivity disorder patients from single nucleotide polymorphism, gene to pathway level. World J Biol Psychiatry 2019; 20:476-485. [PMID: 28971736 PMCID: PMC10752618 DOI: 10.1080/15622975.2017.1386324] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/12/2017] [Accepted: 09/25/2017] [Indexed: 12/31/2022]
Abstract
Objectives: Investigation of the genetic basis of endophenotype and analysis the pathways with multiple genes of small effects might increase the understanding of the genetic basis of attention deficit hyperactivity disorder (ADHD). Here we aimed to explore the genetic basis of cognitive flexibility in ADHD at the single nucleotide polymorphism (SNP), gene and pathway levels. Methods: The trail-making test was used to test the cognitive flexibility of 788 ADHD patients. A genome-wide association analysis of cognitive flexibility was conducted for 644,166 SNPs. Results: The top SNP rs2049161 (P = 5.08e-7) involved gene DLGAP1 and the top gene CADPS2 in the gene-based analysis resulted in much literature evidence of associations with psychiatric disorders. Gene expression and network analysis showed their contribution to cognition function. The interval-enrichment analysis highlighted a potential contribution of 'adenylate cyclase activity' and ADCY2 to cognitive flexibility. Candidate pathway-based analysis for all SNPs found that glutamate system-, neurite outgrowth- and noradrenergic system-related pathways were significantly associated with cognitive flexibility (FDR <0.05), among which the neurite outgrowth pathway was also associated with ADHD symptoms. Conclusions: This study provides evidence for the genes and pathways associated with cognitive flexibility and facilitate the uncovering of the genetic basis of ADHD.
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Affiliation(s)
- Kunlin Zhang
- CAS Key Laboratory of Mental Health, Institute of Psychology, 16 Lincui Road, Beijing 100101, China
- Department of Psychology, University of Chinese Academy of Sciences, 19 A Yuquan Rd, Beijing100049, China
| | - Zili Fan
- Peking University Sixth Hospital (Institute of Mental Health), National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), 51 HuayuanBei Road, Beijing 100191, China
| | - Yufeng Wang
- Peking University Sixth Hospital (Institute of Mental Health), National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), 51 HuayuanBei Road, Beijing 100191, China
| | - Stephen V. Faraone
- Departments of Psychiatry and of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse NY, USA; K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway
| | - Li Yang
- Peking University Sixth Hospital (Institute of Mental Health), National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), 51 HuayuanBei Road, Beijing 100191, China
| | - Suhua Chang
- CAS Key Laboratory of Mental Health, Institute of Psychology, 16 Lincui Road, Beijing 100101, China
- Department of Psychology, University of Chinese Academy of Sciences, 19 A Yuquan Rd, Beijing100049, China
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Sauerzopf U, Sacco R, Novarino G, Niello M, Weidenauer A, Praschak‐Rieder N, Sitte H, Willeit M, Bolam P. Are reprogrammed cells a useful tool for studying dopamine dysfunction in psychotic disorders? A review of the current evidence. Eur J Neurosci 2017; 45:45-57. [PMID: 27690184 PMCID: PMC5811827 DOI: 10.1111/ejn.13418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/23/2016] [Accepted: 09/23/2016] [Indexed: 12/20/2022]
Abstract
Since 2006, reprogrammed cells have increasingly been used as a biomedical research technique in addition to neuro-psychiatric methods. These rapidly evolving techniques allow for the generation of neuronal sub-populations, and have sparked interest not only in monogenetic neuro-psychiatric diseases, but also in poly-genetic and poly-aetiological disorders such as schizophrenia (SCZ) and bipolar disorder (BPD). This review provides a summary of 19 publications on reprogrammed adult somatic cells derived from patients with SCZ, and five publications using this technique in patients with BPD. As both disorders are complex and heterogeneous, there is a plurality of hypotheses to be tested in vitro. In SCZ, data on alterations of dopaminergic transmission in vitro are sparse, despite the great explanatory power of the so-called DA hypothesis of SCZ. Some findings correspond to perturbations of cell energy metabolism, and observations in reprogrammed cells suggest neuro-developmental alterations. Some studies also report on the efficacy of medicinal compounds to revert alterations observed in cellular models. However, due to the paucity of replication studies, no comprehensive conclusions can be drawn from studies using reprogrammed cells at the present time. In the future, findings from cell culture methods need to be integrated with clinical, epidemiological, pharmacological and imaging data in order to generate a more comprehensive picture of SCZ and BPD.
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Affiliation(s)
- Ulrich Sauerzopf
- Department of Psychiatry and PsychotherapyMedical University of ViennaWähringer Gürtel 18‐201090ViennaAustria
| | - Roberto Sacco
- Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Gaia Novarino
- Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Marco Niello
- Institute of PharmacologyMedical University of ViennaViennaAustria
| | - Ana Weidenauer
- Department of Psychiatry and PsychotherapyMedical University of ViennaWähringer Gürtel 18‐201090ViennaAustria
| | - Nicole Praschak‐Rieder
- Department of Psychiatry and PsychotherapyMedical University of ViennaWähringer Gürtel 18‐201090ViennaAustria
| | - Harald Sitte
- Institute of PharmacologyMedical University of ViennaViennaAustria
| | - Matthäus Willeit
- Department of Psychiatry and PsychotherapyMedical University of ViennaWähringer Gürtel 18‐201090ViennaAustria
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5
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Weidenauer A, Bauer M, Sauerzopf U, Bartova L, Praschak-Rieder N, Sitte HH, Kasper S, Willeit M. Making Sense of: Sensitization in Schizophrenia. Int J Neuropsychopharmacol 2016; 20:1-10. [PMID: 27613293 PMCID: PMC5604613 DOI: 10.1093/ijnp/pyw081] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/07/2016] [Indexed: 12/12/2022] Open
Abstract
Sensitization is defined as a process whereby repeated intermittent exposure to a given stimulus results in an enhanced response at subsequent exposures. Next to robust findings of an increased dopamine synthesis capacity in schizophrenia, empirical data and neuroimaging studies support the notion that the mesolimbic dopamine system of patients with schizophrenia is more reactive compared with healthy controls. These studies led to the conceptualization of schizophrenia as a state of endogenous sensitization, as stronger behavioral response and increased dopamine release after amphetamine administration or exposure to stress have been observed in patients with schizophrenia. These findings have also been integrated into the neurodevelopmental model of the disorder, which assumes that vulnerable neuronal circuits undergo progressive changes during puberty and young adulthood that lead to manifest psychosis. Rodent and human studies have made an attempt to identify the exact mechanisms of sensitization of the dopaminergic system and its association with psychosis. Doing so, several epigenetic and molecular alterations associated with dopamine release, neuroplasticity, and cellular energy metabolism have been discovered. Future research aims at targeting these key proteins associated with sensitization in schizophrenia to enhance the knowledge of the pathophysiology of the illness and pave the way for an improved treatment or even prevention of this severe psychiatric disorder.
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Affiliation(s)
- Ana Weidenauer
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria (Drs Weidenauer, Bauer, Sauerzopf, Bartova, Praschak-Rieder, Kasper, and Willeit); Department of Clinical Pharmacology (Dr Bauer), and Institute of Pharmacology, Medical University of Vienna, Austria (Dr Sitte)
| | - Martin Bauer
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria (Drs Weidenauer, Bauer, Sauerzopf, Bartova, Praschak-Rieder, Kasper, and Willeit); Department of Clinical Pharmacology (Dr Bauer), and Institute of Pharmacology, Medical University of Vienna, Austria (Dr Sitte)
| | - Ulrich Sauerzopf
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria (Drs Weidenauer, Bauer, Sauerzopf, Bartova, Praschak-Rieder, Kasper, and Willeit); Department of Clinical Pharmacology (Dr Bauer), and Institute of Pharmacology, Medical University of Vienna, Austria (Dr Sitte)
| | - Lucie Bartova
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria (Drs Weidenauer, Bauer, Sauerzopf, Bartova, Praschak-Rieder, Kasper, and Willeit); Department of Clinical Pharmacology (Dr Bauer), and Institute of Pharmacology, Medical University of Vienna, Austria (Dr Sitte)
| | - Nicole Praschak-Rieder
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria (Drs Weidenauer, Bauer, Sauerzopf, Bartova, Praschak-Rieder, Kasper, and Willeit); Department of Clinical Pharmacology (Dr Bauer), and Institute of Pharmacology, Medical University of Vienna, Austria (Dr Sitte)
| | - Harald H. Sitte
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria (Drs Weidenauer, Bauer, Sauerzopf, Bartova, Praschak-Rieder, Kasper, and Willeit); Department of Clinical Pharmacology (Dr Bauer), and Institute of Pharmacology, Medical University of Vienna, Austria (Dr Sitte)
| | - Siegfried Kasper
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria (Drs Weidenauer, Bauer, Sauerzopf, Bartova, Praschak-Rieder, Kasper, and Willeit); Department of Clinical Pharmacology (Dr Bauer), and Institute of Pharmacology, Medical University of Vienna, Austria (Dr Sitte).
| | - Matthäus Willeit
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria (Drs Weidenauer, Bauer, Sauerzopf, Bartova, Praschak-Rieder, Kasper, and Willeit); Department of Clinical Pharmacology (Dr Bauer), and Institute of Pharmacology, Medical University of Vienna, Austria (Dr Sitte)
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6
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Moritz AE, Foster JD, Gorentla BK, Mazei-Robison MS, Yang JW, Sitte HH, Blakely RD, Vaughan RA. Phosphorylation of dopamine transporter serine 7 modulates cocaine analog binding. J Biol Chem 2012; 288:20-32. [PMID: 23161550 DOI: 10.1074/jbc.m112.407874] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
As an approach to elucidating dopamine transporter (DAT) phosphorylation characteristics, we examined in vitro phosphorylation of a recombinant rat DAT N-terminal peptide (NDAT) using purified protein kinases. We found that NDAT becomes phosphorylated at single distinct sites by protein kinase A (Ser-7) and calcium-calmodulin-dependent protein kinase II (Ser-13) and at multiple sites (Ser-4, Ser-7, and Ser-13) by protein kinase C (PKC), implicating these residues as potential sites of DAT phosphorylation by these kinases. Mapping of rat striatal DAT phosphopeptides by two-dimensional thin layer chromatography revealed basal and PKC-stimulated phosphorylation of the same peptide fragments and comigration of PKC-stimulated phosphopeptide fragments with NDAT Ser-7 phosphopeptide markers. We further confirmed by site-directed mutagenesis and mass spectrometry that Ser-7 is a site for PKC-stimulated phosphorylation in heterologously expressed rat and human DATs. Mutation of Ser-7 and nearby residues strongly reduced the affinity of rat DAT for the cocaine analog (-)-2β-carbomethoxy-3β-(4-fluorophenyl) tropane (CFT), whereas in rat striatal tissue, conditions that promote DAT phosphorylation caused increased CFT affinity. Ser-7 mutation also affected zinc modulation of CFT binding, with Ala and Asp substitutions inducing opposing effects. These results identify Ser-7 as a major site for basal and PKC-stimulated phosphorylation of native and expressed DAT and suggest that Ser-7 phosphorylation modulates transporter conformational equilibria, shifting the transporter between high and low affinity cocaine binding states.
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Affiliation(s)
- Amy E Moritz
- Department of Biochemistry and Molecular Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota 58203-9037, USA
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Lin Z, Liao Y, Venkatasamy R, Hider RC, Soumyanath A. Amides from Piper nigrum L. with dissimilar effects on melanocyte proliferation in-vitro. J Pharm Pharmacol 2010; 59:529-36. [PMID: 17430636 DOI: 10.1211/jpp.59.4.0007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Abstract
Melanocyte proliferation stimulants are of interest as potential treatments for the depigmentary skin disorder, vitiligo. Piper nigrum L. (Piperaceae) fruit (black pepper) water extract and its main alkaloid, piperine (1), promote melanocyte proliferation in-vitro. A crude chloroform extract of P. nigrum containing piperine was more stimulatory than an equivalent concentration of the pure compound, suggesting the presence of other active components. Piperine (1), guineensine (2), pipericide (3), N-feruloyltyramine (4) and N-isobutyl-2E, 4E-dodecadienamide (5) were isolated from the chloroform extract. Their activity was compared with piperine and with commercial piperlongumine (6) and safrole (7), and synthetically prepared piperettine (8), piperlonguminine (9) and 1-(3, 4-methylenedioxyphenyl)-decane (10). Compounds 6–10 either occur in P. nigrum or are structurally related. Compounds 1, 2, 3, 8 and 9 stimulated melanocyte proliferation, whereas 4, 5, 6, 7 and 10 did not. Comparison of structures suggests that the methylenedioxyphenyl function is essential for melanocyte stimulatory activity. Only those compounds also possessing an amide group were active, although the amino component of the amide group and chain linking it to the methylenedioxyphenyl group can vary. P. nigrum, therefore, contains several amides with the ability to stimulate melanocyte proliferation. This finding supports the traditional use of P. nigrum extracts in vitiligo and provides new lead compounds for drug development for this disease.
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Affiliation(s)
- Zhixiu Lin
- Department of Pharmacy, King's College London, 150 Stamford Street, London SE1 9NN, UK
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Zhang Z, Ottens AK, Larner SF, Kobeissy FH, Williams ML, Hayes RL, Wang KKW. Direct Rho-associated kinase inhibition [correction of inhibiton] induces cofilin dephosphorylation and neurite outgrowth in PC-12 cells. Cell Mol Biol Lett 2009; 11:12-29. [PMID: 16847745 PMCID: PMC6276008 DOI: 10.2478/s11658-006-0002-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2005] [Accepted: 11/03/2005] [Indexed: 01/10/2023] Open
Abstract
Axons fail to regenerate in the adult central nervous system (CNS) following injury. Developing strategies to promote axonal regeneration is therapeutically attractive for various CNS pathologies such as traumatic brain injury, stroke and Alzheimer’s disease. Because the RhoA pathway is involved in neurite outgrowth, Rho-associated kinases (ROCKs), downstream effectors of GTP-bound Rho, are potentially important targets for axonal repair strategies in CNS injuries. We investigated the effects and downstream mechanisms of ROCK inhibition in promoting neurite outgrowth in a PC-12 cell model. Robust neurite outgrowth (NOG) was induced by ROCK inhibitors Y-27632 and H-1152 in a time-and dose-dependent manner. Dramatic cytoskeletal reorganization was noticed upon ROCK inhibition. NOG initiated within 5 to 30 minutes followed by neurite extension between 6 and 10 hours. Neurite processes were then sustained for over 24 hours. Rapid cofilin dephosphorylation was observed within 5 minutes of Y-27632 and H-1152 treatment. Re-phosphorylation was observed by 6 hours after Y-27632 treatment, while H-1152 treatment produced sustained cofilin dephosphorylation for over 24 hours. The results suggest that ROCK-mediated dephosphorylation of cofilin plays a role in the initiation of NOG in PC-12 cells.
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Affiliation(s)
- Zhiqun Zhang
- Centers for Neuroproteomics and Biomarkers Research, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Traumatic Brain Injury Studies, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Departments of Neuroscience, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
| | - Andrew K. Ottens
- Centers for Neuroproteomics and Biomarkers Research, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Traumatic Brain Injury Studies, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Departments of Neuroscience, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
| | - Stephen F. Larner
- Traumatic Brain Injury Studies, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Departments of Neuroscience, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
| | - Firas H. Kobeissy
- Centers for Neuroproteomics and Biomarkers Research, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Traumatic Brain Injury Studies, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Departments of Neuroscience, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
| | - Melissa L. Williams
- Departments of Neuroscience, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
| | - Ronald L. Hayes
- Traumatic Brain Injury Studies, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Departments of Neuroscience, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Psychiatry, McKnight Brain Institute, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
| | - Kevin K. W. Wang
- Centers for Neuroproteomics and Biomarkers Research, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Traumatic Brain Injury Studies, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Departments of Neuroscience, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
- Psychiatry, McKnight Brain Institute, University of Florida, P.O. Box 100256, 100 S. Newell Drive, Gainesville, Florida 32610 USA
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Domino EF, Tsukada H. Nicotine sensitization of monkey striatal dopamine release. Eur J Pharmacol 2009; 607:91-5. [PMID: 19232339 DOI: 10.1016/j.ejphar.2009.02.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 01/20/2009] [Accepted: 02/09/2009] [Indexed: 11/26/2022]
Abstract
This study with monkeys was designed to answer two questions. 1) Does acute nicotine preferentially release more dopamine in the striatum than in the prefrontal cortex? 2) Do repeated doses of nicotine produce sensitization of striatal dopamine release? Microdialysis techniques were used to measure extracellular dopamine in both brain regions in two separate groups of conscious animals. The acute nicotine i.v. dose schedule was a bolus of 32 microg/kg plus an infusion of +/-0.8 microg/kg/min and a 100 microg/kg bolus plus an infusion of +/-2.53 microg/kg/min for 30 min to mimic human tobacco smoking arterial plasma nicotine concentrations. Acute nicotine given i.v. released more dopamine in the striatum than in the prefrontal cortex. In the second experiment, for convenience, daily nicotine was given i.m. and not i.v. bid in doses of 32 or 100 microg/kg for nine days. Dopamine release was measured after overnight nicotine abstinence using the i.v. dose schedule from the first experiment. Baseline dopamine release was significantly reduced (77.6% of control, P<0.05). With a lowered baseline, a greater facilitation of dopamine release was produced by nicotine compared to that obtained under control conditions when the baseline was higher. The impaired dopamine release with overnight nicotine abstinence was transiently enhanced in a dose dependent manner. These data regarding the striatum are consistent with previous findings in rodents of nicotine sensitization of dopamine release especially in nucleus accumbens following repeated administration.
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Affiliation(s)
- Edward F Domino
- Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Shizuoka 484-6601, Japan.
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Collo G, Zanetti S, Missale C, Spano P. Dopamine D3 receptor-preferring agonists increase dendrite arborization of mesencephalic dopaminergic neurons via extracellular signal-regulated kinase phosphorylation. Eur J Neurosci 2009; 28:1231-40. [PMID: 18973551 DOI: 10.1111/j.1460-9568.2008.06423.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clinical improvements in Parkinson's disease produced by dopamine D3 receptor-preferring agonists have been related to their neuroprotective actions and, more recently, to their neuroregenerative properties. However, it is unclear whether dopamine agonists produce their neurotrophic effects by acting directly on receptors expressed by the mesencephalic dopaminergic neurons or indirectly on receptors expressed by astrocytes, via release of neurotrophic factors. In this study, we investigated the effects of the dopamine D3 receptor-preferring agonists quinpirole and 7-hydroxy-N,N-di-propyl-2-aminotetralin (7-OH-DPAT), as well as of the indirect agonist amphetamine, on dopaminergic neurons identified by tyrosine hydroxylase immunoreactivity (TH-IR). Experiments were performed on neuronal-enriched primary cultures containing less than 0.5% of astrocytes prepared from the mouse embryo mesencephalon. After 3 days of incubation, both quinpirole (1-10 microm) and 7-OH-DPAT (5-500 nm) dose-dependently increased the maximal dendrite length (P < 0.001), number of primary dendrites (P < 0.01) and [3H]dopamine uptake (P < 0.01) of TH-IR-positive mesencephalic neurons. Similar effects were observed with 10 microm amphetamine. All neurotrophic effects were blocked by the unselective D2/D3 receptor antagonist sulpiride (5 microm) and by the selective D3 receptor antagonist SB-277011-A at a low dose (50 nm). Quinpirole and 7-OH-DPAT also increased the phosphorylation of extracellular signal-regulated kinase (ERK) within minutes, an effect blocked by pretreatment with SB-277011-A. Inhibition of the D2/D3 receptor signalling pathway to ERK was obtained with PD98059, GF109203 or LY294002, resulting in blockade of neurotrophic effects. These data suggest that dopamine agonists increase dendritic arborizations of mesencephalic dopaminergic neurons via a direct effect on D2/D3 receptors, preferentially involving D3 receptor-dependent neurotransmission.
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Affiliation(s)
- Ginetta Collo
- Department of Biomedical Sciences and Biotechnologies, Division of Pharmacology and National Institute of Neuroscience-Italy, Brescia University Medical School, viale Europa 11, 25123 Brescia, Italy.
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Kita T, Miyazaki I, Asanuma M, Takeshima M, Wagner GC. Dopamine-Induced Behavioral Changes and Oxidative Stress in Methamphetamine-Induced Neurotoxicity. NEW CONCEPTS OF PSYCHOSTIMULANT INDUCED NEUROTOXICITY 2009; 88:43-64. [DOI: 10.1016/s0074-7742(09)88003-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Harrill JA, Li Z, Wright FA, Radio NM, Mundy WR, Tornero-Velez R, Crofton KM. Transcriptional response of rat frontal cortex following acute in vivo exposure to the pyrethroid insecticides permethrin and deltamethrin. BMC Genomics 2008; 9:546. [PMID: 19017407 PMCID: PMC2626604 DOI: 10.1186/1471-2164-9-546] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Accepted: 11/18/2008] [Indexed: 12/23/2022] Open
Abstract
Background Pyrethroids are neurotoxic pesticides that interact with membrane bound ion channels in neurons and disrupt nerve function. The purpose of this study was to characterize and explore changes in gene expression that occur in the rat frontal cortex, an area of CNS affected by pyrethroids, following an acute low-dose exposure. Results Rats were acutely exposed to either deltamethrin (0.3 – 3 mg/kg) or permethrin (1 – 100 mg/kg) followed by collection of cortical tissue at 6 hours. The doses used range from those that cause minimal signs of intoxication at the behavioral level to doses well below apparent no effect levels in the whole animal. A statistical framework based on parallel linear (SAM) and isotonic regression (PIR) methods identified 95 and 53 probe sets as dose-responsive. The PIR analysis was most sensitive for detecting transcripts with changes in expression at the NOAEL dose. A sub-set of genes (Camk1g, Ddc, Gpd3, c-fos and Egr1) was then confirmed by qRT-PCR and examined in a time course study. Changes in mRNA levels were typically less than 3-fold in magnitude across all components of the study. The responses observed are consistent with pyrethroids producing increased neuronal excitation in the cortex following a low-dose in vivo exposure. In addition, Significance Analysis of Function and Expression (SAFE) identified significantly enriched gene categories common for both pyrethroids, including some relating to branching morphogenesis. Exposure of primary cortical cell cultures to both compounds resulted in an increase (~25%) in the number of neurite branch points, supporting the results of the SAFE analysis. Conclusion In the present study, pyrethroids induced changes in gene expression in the frontal cortex near the threshold for decreases in ambulatory motor activity in vivo. The penalized regression methods performed similarly in detecting dose-dependent changes in gene transcription. Finally, SAFE analysis of gene expression data identified branching morphogenesis as a biological process sensitive to pyrethroids and subsequent in vitro experiments confirmed this predicted effect. The novel findings regarding pyrethroid effects on branching morphogenesis indicate these compounds may act as developmental neurotoxicants that affect normal neuronal morphology.
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Affiliation(s)
- Joshua A Harrill
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
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13
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Einat H, Yuan P, Szabo ST, Dogra S, Manji HK. Protein kinase C inhibition by tamoxifen antagonizes manic-like behavior in rats: implications for the development of novel therapeutics for bipolar disorder. Neuropsychobiology 2007; 55:123-31. [PMID: 17641532 DOI: 10.1159/000106054] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Accepted: 03/24/2007] [Indexed: 11/19/2022]
Abstract
RATIONALE In the context of bipolar disorder (BPD) research it was demonstrated that administration of the structurally dissimilar mood stabilizers lithium and valproate produced a striking reduction in protein kinase C (PKC) in rat brain. In a small clinical study, tamoxifen (a PKC inhibitor) had antimanic efficacy. However, both lithium and valproate exert many biochemical changes and attribution of therapeutic relevance to any molecular findings needs to be based on linking them to behavioral effects. OBJECTIVES The present study was designed to explore such relationship by studying the effects of PKC inhibition in amphetamine-induced behavioral animal models of mania and changes in GAP-43. METHODS The effects of two daily tamoxifen (1 mg/kg) i.p. injections on acute or chronic (7 injections) amphetamine (0.5 mg/kg) -induced behaviors and GAP-43 phosphorylation were tested. RESULTS The study demonstrates that tamoxifen significantly reduced amphetamine-induced hyperactivity in a large open field without affecting spontaneous activity levels and normalized amphetamine-induced increase in visits to the center of an open field (representing risk-taking behavior). Tamoxifen also attenuated amphetamine-induced phosphorylation of GAP-43, a result that is consistent with the behavioral findings. CONCLUSIONS These results support the possibility that PKC signaling may play an important role in the pathophysiology and treatment of BPD. These findings may have direct clinical implications as they offer a new avenue for attempts to develop more specific drugs for the disorder.
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Affiliation(s)
- Haim Einat
- University of Minnesota, College of Pharmacy, Duluth, MN 55812, USA.
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14
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Thwar PK, Guptaroy B, Zhang M, Gnegy ME, Burns MA, Linderman JJ. Simple transporter trafficking model for amphetamine-induced dopamine efflux. Synapse 2007; 61:500-14. [PMID: 17415796 DOI: 10.1002/syn.20390] [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: 12/15/2022]
Abstract
Amphetamine and its derivatives are important drugs of abuse causing both short-term excitatory and long-term addictive effects. The short-term excitatory effects are linked to amphetamine's ability to maintain high levels of dopamine (DA) outside the cell both by inhibiting DA reuptake after synaptic transmission and by enhancing the efflux of DA from the dopaminergic cells. The molecular mechanisms by which amphetamine elicits the efflux of DA and similar monoamines are still unclear. Recent literature data suggest that trafficking of the monoamine transporters is a phenomenon that underlies observed changes in amphetamine-induced monoamine reuptake and efflux. We develop an ordinary differential equation model incorporating the diverse mechanistic details behind amphetamine-induced DA efflux and demonstrate its utility in describing our experimental data. We also demonstrate an experimental method to track the time-varying concentration of membrane-bound transporter molecules from the DA efflux data. The good fit between our model and the experimental data supports the hypothesis that amphetamine-induced transporter trafficking is necessary to produce extended efflux of DA. This model can explain the relative significance of different processes associated with DA efflux at different times and at different concentration ranges of amphetamine and DA.
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Affiliation(s)
- Prasanna K Thwar
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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15
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Gao J, Kim YM, Coe H, Zern B, Sheppard B, Wang Y. A neuroinductive biomaterial based on dopamine. Proc Natl Acad Sci U S A 2006; 103:16681-6. [PMID: 17075054 PMCID: PMC1636515 DOI: 10.1073/pnas.0606237103] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Chemical messengers such as neurotransmitters play an important role in cell communication, differentiation, and survival. We have designed and synthesized a bioactive biomaterial that derived its biological activity from dopamine. The resultant biodegradable polymer, PCD, has pendent groups bearing dopamine functionalities. Image analysis demonstrated that nerve growth factor-primed rat pheochromocytoma cells (PC12) and explanted rat dorsal root ganglions attached well and displayed substantial neurite outgrowth on the polymer surface. Furthermore, PCD promoted more vigorous neurite outgrowth in PC12 cells than tissue culture polystyrene, laminin, and poly(d-lysine). The histogram of neurite length of PC12 cells showed distinctive patterns on PCD that were absent on the controls. A subset of PC12 cells displayed high filopodium density on PCD. The addition of dopamine in culture medium had little effect on the differentiation of PC12 cells on tissue culture polystyrene. Tyrosine, the precursor of dopamine, did not exhibit this ability to impart specific bioactivity to an analogous polymer. Thus, the dopamine functional group is likely the origin of the inductive effect. PCD did not cause nerve degeneration or fibrous encapsulation when implanted immediately adjacent to the rat sciatic nerves. This work is a step toward creating a diverse family of bioactive materials using small chemical messengers as monomers.
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Affiliation(s)
- Jin Gao
- *Department of Biomedical Engineering, School of Chemistry and Biochemistry, and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332
| | - Yu Mi Kim
- *Department of Biomedical Engineering, School of Chemistry and Biochemistry, and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332
- Department of Biological and Medical Engineering, Kyungpook National University, Daegu 702-701, Korea; and
| | - Herna Coe
- *Department of Biomedical Engineering, School of Chemistry and Biochemistry, and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332
| | - Blaine Zern
- *Department of Biomedical Engineering, School of Chemistry and Biochemistry, and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332
| | - Barbara Sheppard
- College of Veterinary Medicine, University of Florida, Gainesville, FL 32611
| | - Yadong Wang
- *Department of Biomedical Engineering, School of Chemistry and Biochemistry, and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332
- To whom correspondence should be addressed. E-mail:
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Shi X, McGinty JF. Extracellular signal-regulated mitogen-activated protein kinase inhibitors decrease amphetamine-induced behavior and neuropeptide gene expression in the striatum. Neuroscience 2006; 138:1289-98. [PMID: 16459022 DOI: 10.1016/j.neuroscience.2005.12.024] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 11/18/2005] [Accepted: 12/01/2005] [Indexed: 11/16/2022]
Abstract
The aim of this study was to determine whether inhibition of the extracellular-regulated kinase signaling pathway decreases acute amphetamine-induced behavioral activity and neuropeptide gene expression in the rat striatum. Western blotting revealed that extracellular-regulated kinase1/2 phosphorylation was highly induced in the rat striatum 15 min after an acute amphetamine (2.5 mg/kg, i.p.) injection without altering the total amount of extracellular-regulated kinase protein. In a separate experiment, the systemic injection of SL327, a selective inhibitor of extracellular regulated kinase kinase that crosses the blood-brain barrier, 1 h prior to amphetamine administration decreased amphetamine-induced vertical and horizontal activity. Quantitative in situ hybridization histochemistry showed that SL327 abolished the high levels of preproenkephalin and preprodynorphin mRNA induced by amphetamine in the striatum with no alteration of their basal levels. In another set of experiments, the hyperlocomotor activity induced by amphetamine was reduced by pretreatment with intra-striatal infusion of U0126. U0126 also blocked the amphetamine-induced increases in phospho-extracellular-regulated kinase and preproenkephalin and preprodynorphin gene expression in the striatum. These data indicate that activation of the extracellular-regulated kinase cascade contributes to the behavioral effects and changes in striatal neuropeptide gene expression induced by acute amphetamine.
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Affiliation(s)
- X Shi
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, BSB 403, Charleston, SC 29425, USA
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17
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Nguyen-Vu TDB, Chen H, Cassell AM, Andrews R, Meyyappan M, Li J. Vertically aligned carbon nanofiber arrays: an advance toward electrical-neural interfaces. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2006; 2:89-94. [PMID: 17193561 DOI: 10.1002/smll.200500175] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
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18
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Narita M, Akai H, Kita T, Nagumo Y, Narita M, Sunagawa N, Hara C, Hasebe K, Nagase H, Suzuki T. Involvement of mitogen-stimulated p70-S6 kinase in the development of sensitization to the methamphetamine-induced rewarding effect in rats. Neuroscience 2005; 132:553-60. [PMID: 15837117 DOI: 10.1016/j.neuroscience.2004.12.050] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2004] [Indexed: 10/25/2022]
Abstract
The neural plasticity associated with behavioral sensitization following repeated administration of a psychostimulant methamphetamine (METH) is thought to require synthesis of new proteins. The aim of the present study was to investigate the role of p70-S6 kinase (p70-S6K) phosphorylation, which contributes to the selective translation of a unique family of mRNA, in mediating both the METH-induced rewarding effect and its sensitization. An intra-nucleus accumbens (N.Acc.) pre-injection with 0.025 pmol/rat of a selective p70-S6K inhibitor rapamycin failed to affect the METH-induced conditioned place preference. However, this treatment clearly abolished the development of sensitization of the METH-induced conditioned place preference. Consistent with the behavioral assay, the level of the immunoreactivity of phosporylated-p70-S6K was not changed in the cytosolic fraction of the N.Acc. obtained from rats that had revealed the METH-induced rewarding effect. In contrast, the immunoreactivities in the cytosolic preparation for Western blotting and immunohistochemical density of phosphorylated-p70-S6K were significantly increased in the N.Acc. obtained from METH-sensitized rats as compared with those with chronic saline treatment. However, the immunoreactivities of phosphorylated-extracellular signal-regulated kinase and phosphorylated-ribosomal S6 protein were not significantly altered in the N.Acc. under the same condition. The present data provide evidence for the change in the translation rate, which can be regulated by S6K phosphorylation, in the N.Acc. during the development of sensitization to METH-induced rewarding effects in rats.
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Affiliation(s)
- M Narita
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Shinagawa-ku, Tokyo 142-8501, Japan.
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19
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Nemoto T, Mano-Otagiri A, Shibasaki T. Urocortin 2 induces tyrosine hydroxylase phosphorylation in PC12 cells. Biochem Biophys Res Commun 2005; 330:821-31. [PMID: 15809070 DOI: 10.1016/j.bbrc.2005.03.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Indexed: 10/25/2022]
Abstract
Urocotins (Ucns) are newly discovered members of the corticotropin-releasing factor (CRF) neuropeptide family. Ucn 2 is expressed in the adrenal medulla, and its receptor, CRF2 receptor, is also expressed in the adrenal gland. To predict the physiological significance of Ucn 2 expression in the adrenal medulla, we examined the effects of Ucn 2 on catecholamine secretion and intracellular signaling using PC12 cells, a rat pheochromocytoma cell line. PC12 cells were found to express CRF2 receptor, but not CRF1 receptor. Treatment with Ucn 2 increased noradrenaline secretion and induced phosphorylation of PKA and Erk1/2. Tyrosine hydroxylase (TH), a rate-limiting enzyme for catecholamine synthesis, was also phosphorylated by Ucn 2. Pretreatment with a PKA inhibitor blocked Ucn 2-induced NA secretion, and Erk1/2 and TH phosphorylation. Pretreatment with a MEK inhibitor did not block Ucn 2-induced noradrenaline secretion or PKA phosphorylation, although TH phosphorylation was blocked. Thus, Ucn 2 induces noradrenaline secretion and TH phosphorylation through the PKA pathway and the PKA-Erk1/2 pathway, respectively. These results suggest Ucn 2 in the adrenal gland may be involved in the regulation of catecholamine release and synthesis.
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Affiliation(s)
- Takahiro Nemoto
- Department of Physiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan.
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20
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Robinson TE, Kolb B. Structural plasticity associated with exposure to drugs of abuse. Neuropharmacology 2004; 47 Suppl 1:33-46. [PMID: 15464124 DOI: 10.1016/j.neuropharm.2004.06.025] [Citation(s) in RCA: 778] [Impact Index Per Article: 38.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Revised: 05/24/2004] [Accepted: 06/30/2004] [Indexed: 11/19/2022]
Abstract
Persistent changes in behavior and psychological function that occur as a function of experience, such those associated with learning and memory, are thought to be due to the reorganization of synaptic connections (structural plasticity) in relevant brain circuits. Some of the most compelling examples of experience-dependent changes in behavior and psychological function, changes that can last a lifetime, are those that accrue with the development of addictions. However, until recently, there has been almost no research on whether potentially addictive drugs produce forms of structural plasticity similar to those associated with other forms of experience-dependent plasticity. In this paper we summarize evidence that, indeed, exposure to amphetamine, cocaine, nicotine or morphine produces persistent changes in the structure of dendrites and dendritic spines on cells in brain regions involved in incentive motivation and reward (such as the nucleus accumbens), and judgment and the inhibitory control of behavior (such as the prefrontal cortex). It is suggested that structural plasticity associated with exposure to drugs of abuse reflects a reorganization of patterns of synaptic connectivity in these neural systems, a reorganization that alters their operation, thus contributing to some of the persistent sequela associated with drug use--including addiction.
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Affiliation(s)
- Terry E Robinson
- Department of Psychology (Biopsychology) and Neuroscience Program, The University of Michigan, 525 E. University (East Hall), Ann Arbor, MI 48109, USA.
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Kantor L, Zhang M, Guptaroy B, Park YH, Gnegy ME. Repeated Amphetamine Couples Norepinephrine Transporter and Calcium Channel Activities in PC12 Cells. J Pharmacol Exp Ther 2004; 311:1044-51. [PMID: 15340003 DOI: 10.1124/jpet.104.071068] [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: 11/22/2022] Open
Abstract
Repeated intermittent amphetamine enhances efflux of dopamine through the dopamine transporter in rat basal ganglia and through the norepinephrine transporter in rat pheochromocytoma PC12 cells. Extracellular Ca2+ is required for the detection of this enhancement in the rat. In this study, we examined the role of Ca2+ and Ca2+ channels in the enhanced amphetamine-induced dopamine efflux that develops in PC12 cells following repeated intermittent amphetamine. Repeated pretreatment of PC12 cells with 1 microM amphetamine followed by a drug-free period increased amphetamine-induced efflux of dopamine compared with controls. The enhancement in amphetamine-induced dopamine efflux depended upon the presence of extracellular Ca2+ and was inhibited by the blockade of N-type and L-type Ca2+ channels. The enhanced dopamine efflux was not altered by tetanus toxin or reserpine, treatments that abrogate synaptic vesicle-mediated, exocytotic dopamine efflux. Measurement of intracellular Ca2+ concentrations using fura-2/acetoxymethyl ester revealed that amphetamine increased intracellular Ca2+ by a transporter-dependent mechanism. In amphetamine-pretreated cells, amphetamine elicited a greater increase in intracellular Ca2+; this increase depended upon the presence of extracellular Ca2+ and N- and L-type Ca2+ channel activity. The enhanced amphetamine-induced dopamine efflux requires Ca2+/calmodulin kinase activity. In vehicle-treated cells, 1 microM amphetamine inhibited the calmodulin kinase activity although it did not in amphetamine-pretreated cells. This study suggests that repeated intermittent amphetamine couples norepinephrine transporter activity and Ca2+ signaling.
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Affiliation(s)
- L Kantor
- Department of Pharmacology, 2220E Medical Science Research Building III, University of Michigan Medical School, Ann Arbor, MI 48109-0632, USA
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