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Villanueva CR, Barksdale K, Owolabi T, Bridges D, Chichester K, Saini S, Oliver ET. Functional human skin explants as tools for assessing mast cell activation and inhibition. FRONTIERS IN ALLERGY 2024; 5:1373511. [PMID: 38601026 PMCID: PMC11004268 DOI: 10.3389/falgy.2024.1373511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/04/2024] [Indexed: 04/12/2024] Open
Abstract
Mast cells are activated through a variety of different receptors to release preformed granules and mediators synthesized de novo. However, the physiology and function of mast cells are not fully understood. Traditional studies of mast cell activation in humans have utilized cultures of tissue-derived mast cells including CD34+ progenitor cells or well-characterized commercially available cell lines. One limitation of these methods is that mast cells are no longer in a natural state. Therefore, their applicability to human skin disorders may be limited. Human skin explant models have been utilized to investigate the short-term effects of cell mediators, drugs, and irritants on skin while avoiding the ethical concerns surrounding in vivo stimulation studies with non-approved agents. Nonetheless, few studies have utilized intact human tissue to study mast cell degranulation. This "Methods" paper describes the development and application of an intact skin explant model to study human mast cell activation. In this manuscript, we share our protocol for setting up ex vivo human skin explants and describe the results of stimulation experiments and techniques to minimize trauma-induced histamine release. Skin explants were generated using de-identified, full-thickness, non-diseased skin specimens from plastic and reconstructive surgeries. Results were reproducible and demonstrated FcɛRI- and MRGPRX2-induced mediator release which was inhibited with the use of a BTK inhibitor and QWF, respectively. Thus, this explant model provides a quick and accessible method of assessing human skin mast cell activation and inhibition.
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Affiliation(s)
| | | | | | | | | | | | - Eric T. Oliver
- Division of Allergy and Clinical Immunology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Microdialysis and its use in behavioural studies: Focus on acetylcholine. J Neurosci Methods 2018; 300:206-215. [DOI: 10.1016/j.jneumeth.2017.08.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 08/01/2017] [Accepted: 08/11/2017] [Indexed: 12/28/2022]
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Lietsche J, Gorka J, Hardt S, Karas M, Klein J. Custom-made Microdialysis Probe Design. J Vis Exp 2015:e53048. [PMID: 26273844 DOI: 10.3791/53048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Microdialysis is a commonly used technique in neuroscience research. Therefore commercial probes are in great demand to monitor physiological, pharmacological and pathological changes in cerebrospinal fluid. Unfortunately, commercial probes are expensive for research groups in public institutions. In this work, a probe assembly is explained in detail to build a reliable, concentric, custom-made microdialysis probe for less than $10. The microdialysis probe consists of a polysulfone membrane with a molecular cut-off of 30 kDa. Probe in vitro recoveries of substances with different molecular weight (in the range of 100-1,600 Da) and different physicochemical properties are compared. The probe yields an in vitro recovery of approximately 20% for the small compounds glucose, lactate, acetylcholine and ATP. In vitro recoveries for neuropeptides with a molecular weight between 1,000-1,600 Da amount to 2-6%. Thus, while the higher molecular weight of the neuropeptides lowered in vitro recovery values, dialysis of compounds in the lower range (up to 500 Da) of molecular weights has no great impact on the in vitro recovery rate. The present method allows utilization of a dialysis membrane with other cut-off value and membrane material. Therefore, this custom-made probe assembly has the advantage of sufficient flexibility to dialyze substances in a broad molecular weight range. Here, we introduce a microdialysis probe with an exchange length of 2 mm, which is applicable for microdialysis in mouse and rat brain regions. However, dimensions of the probe can easily be adapted for larger exchange lengths to be used in larger animals.
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Affiliation(s)
- Jana Lietsche
- Department of Pharmacology, Goethe University of Frankfurt
| | - Jan Gorka
- Department of Pharmaceutical Chemistry, Goethe University of Frankfurt
| | - Stefanie Hardt
- Department of Clinical Pharmacology, Goethe University of Frankfurt
| | - Michael Karas
- Department of Pharmaceutical Chemistry, Goethe University of Frankfurt
| | - Jochen Klein
- Department of Pharmacology, Goethe University of Frankfurt;
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Self-built microdialysis probes with improved recoveries of ATP and neuropeptides. J Neurosci Methods 2014; 237:1-8. [PMID: 25172804 DOI: 10.1016/j.jneumeth.2014.08.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/09/2014] [Accepted: 08/14/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Microdialysis is an established technique for collecting small molecular weight substances (e.g. neurotransmitter and energy metabolites) from the extracellular space. The major element of microdialysis is the probe which contains a semi-permeable membrane and is exposed to the interstitial space. As the microdialysis technique has major advantages, e.g. versatility and use in awake animals, commercially produced probes are in great demand. NEW METHOD We here present the design of a probe assembly step by step which will enable researchers to build custom-made probes. Probe recoveries of substances with different molecular weight (ranging from 100 to 1600 Da) were compared for three different probes (CMA 12 Elite probe, custom-made 10 kDa and 30 kDa probes). Recoveries of glucose, lactate, acetylcholine, choline, ATP and the neuropeptides angiotensin II, substance P and somatostatin are presented. RESULTS We found that the 10 kDa probe is only useful for compounds up to 1000 Da while recoveries of the CMA-12 Elite Probe are variable and apparently dependent on ionic charges of analytes. The recovery of the custom-made 30 kDa probe is highest and evidently not influenced by physicochemical parameters of analytes. In a further optimization step, we describe the use of ZipTip(®) μC-18 collection tips to replace the outlet tubing when purifying the dialysate for MALDI-MS measurements of neuropeptides. COMPARISON WITH EXISTING METHODS The results show that self-built microdialysis probes can be equally or more effective than commercially available probes. CONCLUSIONS Self-built microdialysis probes with large pore-membranes are capable of dialyzing ATP and neuropeptides.
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Duncan KD, Willis MD, Krogh ET, Gill CG. A miniature condensed-phase membrane introduction mass spectrometry (CP-MIMS) probe for direct and on-line measurements of pharmaceuticals and contaminants in small, complex samples. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:1213-1221. [PMID: 23650034 DOI: 10.1002/rcm.6560] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 02/22/2013] [Accepted: 02/23/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE High-throughput, automated analytical measurements are desirable in many analytical scenarios, as are rapid sample pre-screening techniques to identify 'positive' samples for subsequent measurements using more time-consuming conventional methodologies (e.g., liquid chromatography/mass spectrometry (LC/MS)). A miniature condensed-phase membrane introduction mass spectrometry (CP-MIMS) probe for the direct and continuous, on-line measurement of pharmaceuticals and environmental contaminants in small, complex samples is presented. METHODS A miniature polydimethylsiloxane hollow fibre membrane (PDMS-HFM) probe is coupled with an electrospray ionization (ESI) triple quadrupole mass spectrometer. Analytes are transported from the probe to the ESI source by a methanol acceptor phase. The probe can be autosampler mounted and directly inserted in small samples (≥400 μL) allowing continuous and simultaneous pptr-ppb level detection of target analytes (chlorophenols, triclosan, gemfibrozil, nonylphenol) in complex samples (artificial urine, beer, natural water, waste water, plant tissue). RESULTS The probe has been characterized and optimized for acceptor phase flow rate, sample mixing and probe washing. Signal response times, detection limits and calibration data are given for selected ion monitoring (SIM) and tandem mass spectrometry (MS/MS) measurements of target analytes at trace levels. Comparisons with flow cell type CP-MIMS systems are given. Analyte depletion effects are evaluated for small samples (≥400 μL). On-line measurements in small volumes of complex samples, temporally resolved reaction monitoring and in situ/in vivo demonstrations are presented. CONCLUSIONS The miniature CP-MIMS probe developed was successfully used for the direct, on-line detection of target analytes in small volumes (40 mL to 400 μL) of complex samples at pptr to low ppb levels. The probe can be readily automated as well as deployed for in situ/in vivo monitoring, including reaction monitoring, small sample measurements and direct insertion in living plant tissue.
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Affiliation(s)
- Kyle D Duncan
- Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada
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Evidence that conditioned avoidance responses are reinforced by positive prediction errors signaled by tonic striatal dopamine. Behav Brain Res 2013; 241:112-9. [DOI: 10.1016/j.bbr.2012.06.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 06/23/2012] [Accepted: 06/27/2012] [Indexed: 11/18/2022]
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Cortright JJ, Lorrain DS, Beeler JA, Tang WJ, Vezina P. Previous exposure to delta9-tetrahydrocannibinol enhances locomotor responding to but not self-administration of amphetamine. J Pharmacol Exp Ther 2011; 337:724-33. [PMID: 21389094 DOI: 10.1124/jpet.111.180208] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Previous exposure to amphetamine leads to enhanced locomotor and nucleus accumbens (NAcc) dopamine (DA) responding to the drug as well as enhanced amphetamine self-administration. Here, we investigated the effects of exposure to Δ(9)-tetrahydrocannibinol (Δ(9)-THC) on behavioral and biochemical responding to amphetamine. Rats in different groups received five exposure injections of vehicle or one of five doses of Δ(9)-THC (0.4, 0.75, 1.5, 3.0, and 6.0 mg/kg i.p.) and were tested 2 days and 2 weeks later. Exposure to all but the lowest and highest doses of Δ(9)-THC enhanced the locomotor response to amphetamine (0.75 mg/kg i.p.), but all failed to enhance NAcc DA overflow in response to the drug. Moreover, exposure to 3.0 mg/kg i.p. Δ(9)-THC increased forskolin-evoked adenylyl cyclase activity in the NAcc and rats' locomotor response to the direct DA receptor agonist apomorphine (1.0 mg/kg s.c.), suggesting that Δ(9)-THC sensitized locomotor responding to amphetamine by up-regulating postsynaptic DA receptor signaling in the NAcc. Finally, amphetamine self-administration (200 μg/kg/infusion i.v.) was enhanced in amphetamine (5 × 1.5 mg/kg i.p.)-exposed rats, but not in rats exposed to Δ(9)-THC (5 × 3.0 mg/kg i.p.). Previous exposure to this dose of Δ(9)-THC modestly increased apomorphine SA (0.5 mg/kg/infusion i.v.). Thus, unlike amphetamine exposure, exposure to Δ(9)-THC does not enhance the subsequent NAcc DA response to amphetamine or promote amphetamine self-administration. Although Δ(9)-THC leads to alterations in postsynaptic DA receptor signaling in the NAcc and these can affect the generation of locomotion, these neuroadaptations do not seem to be linked to the expression of enhanced amphetamine self-administration.
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Affiliation(s)
- James J Cortright
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 South Maryland Avenue, Chicago, IL 60637, USA
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Dombrowski PA, Carvalho MC, Miyoshi E, Correia D, Bortolanza M, dos Santos LM, Wietzikoski EC, Eckart MT, Schwarting RK, Brandão ML, Da Cunha C. Microdialysis study of striatal dopamine in MPTP-hemilesioned rats challenged with apomorphine and amphetamine. Behav Brain Res 2010; 215:63-70. [DOI: 10.1016/j.bbr.2010.06.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 06/22/2010] [Indexed: 10/19/2022]
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Loweth JA, Svoboda R, Austin JD, Guillory AM, Vezina P. The PKC inhibitor Ro31-8220 blocks acute amphetamine-induced dopamine overflow in the nucleus accumbens. Neurosci Lett 2009; 455:88-92. [PMID: 19368852 DOI: 10.1016/j.neulet.2009.03.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Revised: 03/03/2009] [Accepted: 03/03/2009] [Indexed: 10/21/2022]
Abstract
Acute administration of the psychostimulant amphetamine increases extracellular levels of dopamine (DA) by reversing the DA transporter on ascending midbrain DA neurons. In vitro studies using striatal synaptosomal, slice and nucleus accumbens (NAcc) tissue preparations have implicated protein kinase C (PKC) in this effect. The present study further examined this effect in vivo by assessing the ability of the PKC inhibitor, Ro31-8220 (10 microM), to inhibit acute amphetamine-induced DA overflow when applied with this drug to the NAcc via reverse dialysis. Amphetamine was applied at a concentration of 30 microM, and the core and shell subregions of the NAcc were assayed separately in freely moving rats. These brain regions play a role in the acute locomotor-activating and motivational effects of amphetamine. Consistent with the findings of previous in vitro experiments, reverse dialysis of Ro31-8220 with amphetamine robustly attenuated the ability of this drug to increase extracellular levels of dopamine in both the core and shell subregions of the NAcc. These results confirm that amphetamine stimulates dopamine overflow via a PKC-dependent mechanism.
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Affiliation(s)
- Jessica A Loweth
- Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, USA.
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Yamamoto N, Pierce RC, Soghomonian JJ. Subchronic administration of l-DOPA to adult rats with a unilateral 6-hydroxydopamine lesion of dopamine neurons results in a sensitization of enhanced GABA release in the substantia nigra, pars reticulata. Brain Res 2006; 1123:196-200. [PMID: 17027936 DOI: 10.1016/j.brainres.2006.09.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2006] [Revised: 09/08/2006] [Accepted: 09/08/2006] [Indexed: 11/30/2022]
Abstract
L-DOPA is the most effective pharmacological agent used for the symptomatic treatment of Parkinson's disease but long-term L-DOPA treatment induces involuntary abnormal movements such as dyskinesias. The present study, using in vivo microdialysis, investigated the effects of a single or subchronic administration of L-DOPA to adult rats with a unilateral 6-OHDA lesion of dopamine neurons on GABA release in the substantia nigra, pars reticulata (SNr). The results indicate that a challenge injection of L-DOPA (50 mg/kg, i.p.) significantly increases GABA levels in the SNr of rats treated with a daily repeated administration of L-DOPA (50 mg/kg, i.p.). Further statistical analysis between groups also showed that extracellular GABA levels were significantly higher in the subchronic L-DOPA group than in the group receiving only one injection of L-DOPA. These results show that the subchronic administration of L-DOPA results in a sensitization of enhanced extracellular GABA levels in the SNr.
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Affiliation(s)
- Noriko Yamamoto
- Department of Anatomy and Neurobiology, Boston University School of Medicine, 715 Albany Street, Room L1001, Boston, MA 02118, USA
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Raje S, Cornish J, Newman AH, Cao J, Katz JL, Eddington ND. Investigation of the potential pharmacokinetic and pharmaco-dynamic drug interaction between AHN 1-055, a potent benztropine analog used for cocaine abuse, and cocaine after dosing in rats using intracerebral microdialysis. Biopharm Drug Dispos 2006; 27:229-40. [PMID: 16586462 DOI: 10.1002/bdd.497] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
PURPOSE AHN 1-055, a benztropine (BZT) analog, binds with high affinity to the dopamine transporter (DAT), possesses behavioral, pharmacokinetic (PK) and brain microdialysate dopamine (DA) profiles distinct from cocaine. Accordingly, the objectives of this study were to evaluate the pharmacokinetics and dopamine release of AHN 1-055, in the presence of cocaine. METHODS Male Sprague Dawley rats ( approximately 300 g) were administered 5 mg/kg of AHN 1-055 and cocaine i.v. and blood and brain samples were collected over 36 h. In addition, dialysis probes were stereotaxically implanted into the nucleus accumbens and extracellular fluid (ECF) DA levels were measured. PK and PD models were used to describe the relationship between the AHN 1-055, cocaine and DA levels. RESULTS No significant (p< 0.05) differences were found in the PK parameters of AHN 1-055 alone (V(dss) = 18.7 l/kg, Cl = 1.8 l/h/kg and t(1/2) = 7.69 h) or AHN 1-055 with cocaine (V(dss)=17.4 l/kg, Cl = 1.9 l/h/kg and t(1/2) = 6.82 h). The brain-to-plasma (B/P) ratios (B/P(AHN 1-055) = 4.8 vs B/P(with cocaine) = 4.4) and half-lives (t(1/2(AHN 1-055)) = 6.2 h vs t(1/2(cocaine) = )5.6 h for AHN 1-055 alone and with cocaine were comparable. AHN 1-055 DA profiles were significantly different after co-administration with cocaine. There were no differences in the IC(50) for AHN 1-055, with cocaine, however, the IC(50) for cocaine was significantly reduced with AHN 1-055. CONCLUSIONS The PK parameters of AHN 1-055 were not changed, however, the effect on DA levels was affected when cocaine was administered with AHNDA profile is affected when dosed with cocaine. This latter effect is a desirable attribute in the development of a medication as a potential substitute therapeutic medication for the treatment of cocaine abuse.
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Affiliation(s)
- Sangeeta Raje
- Pharmacokinetics Biopharmaceutics Laboratory, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, 21201-6808, USA
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Raje S, Cornish J, Newman AH, Cao J, Katz JL, Eddington ND. Pharmacodynamic assessment of the benztropine analogues AHN-1055 and AHN-2005 using intracerebral microdialysis to evaluate brain dopamine levels and pharmacokinetic/pharmacodynamic modeling. Pharm Res 2005; 22:603-12. [PMID: 15846468 DOI: 10.1007/s11095-005-2488-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Accepted: 01/12/2005] [Indexed: 11/30/2022]
Abstract
PURPOSE The benztropine (BZT) analogues bind with high affinity to the dopamine transporter (DAT) and demonstrate a behavioral and pharmacokinetic profile unlike that of cocaine. The development of a predictive pharmacokinetic/pharmacodynamic (PK/PD) model to characterize the concentration-effect relationship between the BZT analogues and brain dopamine (DA) levels is an important step in the evaluation of these compounds as potential cocaine abuse pharmacotherapies. Hence, the objective of this study was to mathematically characterize the PD of BZT analogues and cocaine, using appropriate PK/PD models. METHODS Dialysis probes were stereotaxically implanted into the nucleus accumbens of Sprague-Dawley rats (275-300 g). Extracellular fluid (ECF) DA levels were measured after intravenous administration of the BZT analogues AHN-1055 and AHN-2005, as well as cocaine using high performance liquid chromatography-electrochemical detection (HPLC-ECD). PD models were used to describe the relationship between the BZT analogues or cocaine and brain microdialysate DA, and suitability was based on standard goodness-of-fit criteria. RESULTS The BZT analogues produced a sustained increase in brain microdialysate DA levels in comparison to cocaine. The time of maximum concentration (T(max)) for brain microdialysate DA was 2 h for AHN-1055 and 1 h for AHN-2005 compared to a T(max) of 10 min for cocaine. The duration of brain microdialysate DA elevation was approximately 12-24 h for the BZTs in comparison to 1 h for cocaine. An indirect model with inhibition of loss of response and a sigmoid E(max) model best described the PK/PD for the BZT analogues and cocaine, respectively. The 50% of maximum inhibition (IC(50)) of the loss of DA was lower for AHN-2005 (226 +/- 27.5 ng/ml) compared to AHN-1055 (321 +/- 19.7 ng/ml). In addition, the EC(50) for cocaine was 215 +/- 11.2 ng/ml. CONCLUSIONS The slow onset and long duration of BZT analogue-induced DA elevation may avoid the reinforcing effects and craving of cocaine. Further, the developed models will be useful in characterizing the PK/PD of other analogues and aid in the assessment of the therapeutic efficacy of the BZT analogues as substitute medications for cocaine abuse.
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Affiliation(s)
- Sangeeta Raje
- Pharmacokinetics Biopharmaceutics Laboratory, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, USA
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Tanabe LM, Suto N, Creekmore E, Steinmiller CL, Vezina P. Blockade of D2 dopamine receptors in the VTA induces a long-lasting enhancement of the locomotor activating effects of amphetamine. Behav Pharmacol 2004; 15:387-95. [PMID: 15343065 DOI: 10.1097/00008877-200409000-00013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The present study examined the effects of pre-exposure to eticlopride, a D2 dopamine receptor antagonist, in the ventral tegmental area (VTA) on the subsequent locomotor activating effects of amphetamine (AMPH). Rats were pre-exposed to one of three doses of eticlopride (0.75, 3.0 or 12.0 microg/0.5 microl per side) or saline (0.5 microl/side) in the VTA, once every third day, for a total of three infusions. Locomotor activity was recorded for 2 h following each pre-exposure injection. The low and intermediate doses of eticlopride produced no effects, while the high dose decreased locomotor activity compared to saline controls. 10-14 days following the last pre-exposure injection, all rats were challenged with AMPH (1.0 mg/kg, ip) and locomotor activity was recorded. Rats pre-exposed to the low dose of eticlopride exhibited enhanced locomotor activity whereas those pre-exposed to the intermediate or high doses did not differ from saline pre-exposed controls, suggesting that blockade of D2 dopamine receptors in the VTA can lead to sensitized locomotor responding to AMPH. To investigate the possible mechanism by which the low dose of eticlopride induced sensitization, extracellular levels of dopamine were measured as increasing concentrations of eticlopride (0.1, 1.0, 10.0 and 100.0 micromol/l) were perfused through a microdialysis probe implanted in the VTA. Only the lowest eticlopride concentration elevated extracellular dopamine levels. Therefore, as in the case of AMPH-induced sensitization, the induction by eticlopride of sensitization to AMPH may be initiated by the ability of eticlopride to increase extracellular levels of dopamine in the VTA.
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Affiliation(s)
- L M Tanabe
- Department of Psychiatry, The University of Chicago, 5841 S. Maryland Avenue, Chicago, IL 60637, USA
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Licata SC, Pierce RC. Repeated cocaine injections have no influence on tyrosine hydroxylase activity in the rat nucleus accumbens core or shell. Brain Res 2004; 1012:119-26. [PMID: 15158168 DOI: 10.1016/j.brainres.2004.03.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2004] [Indexed: 11/30/2022]
Abstract
Numerous reports have demonstrated augmented cocaine-evoked release of dopamine in the nucleus accumbens of rats pre-treated with cocaine. However, the extent to which repeated cocaine injections affect basal levels of dopamine is unclear. There have been reports of increases, decreases, or no change in basal levels of extracellular accumbal dopamine resulting from repeated psychostimulant administration. The present study assessed the activity of tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis, in the nucleus accumbens following either acute or repeated cocaine administration. The in vivo microdialysis technique was used to measure accumulation of the dopamine precursor DOPA following intra-accumbal administration of the DOPA decarboxylase inhibitor NSD 1015 through the microdialysis probe. This method provides an estimate of tyrosine hydroxylase activity within the nucleus accumbens. Results indicate that neither acute nor repeated cocaine administration produced any change in DOPA accumulation in either the nucleus accumbens shell or core. These data indicate that dopamine synthesis is not altered by cocaine administration.
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Affiliation(s)
- Stephanie C Licata
- Laboratory of Neuropsychopharmacology, Department of Pharmacology, Boston University School of Medicine, Boston, MA 02118, USA.
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Koeltzow TE, Austin JD, Vezina P. Behavioral sensitization to quinpirole is not associated with increased nucleus accumbens dopamine overflow. Neuropharmacology 2003; 44:102-10. [PMID: 12559127 DOI: 10.1016/s0028-3908(02)00328-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study assessed the relationship between extracellular nucleus accumbens (NAc) dopamine (DA) concentrations and sensitized locomotor activation following repeated administration of the DA D2-like receptor agonist quinpirole. Locomotor activity measures and nucleus accumbens microdialysis samples were collected concurrently in response to the first (acute) and tenth (repeated) quinpirole injection (0.5 mg/kg s.c., every other day). Results indicate that acute quinpirole produced locomotor activation and that repeated quinpirole resulted in locomotor sensitization. Acute quinpirole significantly decreased the detection of extracellular concentrations of DA and the DA metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the NAc. Following repeated quinpirole, basal NAc DA levels were decreased, whereas basal DOPAC levels were increased. Nevertheless, quinpirole challenge elicited a significant decrease in DA, DOPAC and HVA following repeated treatment. In addition, although acute quinpirole did not affect NAc levels of the serotonin metabolite 5-hydroxyindolacetic acid (5-HIAA), quinpirole challenge produced a significant increase in 5-HIAA levels following repeated treatment. Taken together, these data indicate that functional DA autoreceptor subsensitivity is not a necessary condition for the expression of behavioral sensitization to quinpirole. Instead, it appears that behavioral sensitization to quinpirole occurs predominantly as a consequence of neuroadaptations that are post-synaptic to DA release.
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Affiliation(s)
- Timothy E Koeltzow
- Department of Psychiatry, University of Chicago, 5841 S. Maryland Ave. MC 3077, Chicago, IL 60637, USA
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Neubert JK, Matsuka Y, Maidment NT, Spigelman I. Microdialysis in trigeminal ganglia. BRAIN RESEARCH. BRAIN RESEARCH PROTOCOLS 2002; 10:102-8. [PMID: 12431709 DOI: 10.1016/s1385-299x(02)00188-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Recent evidence demonstrates that neurons in sensory ganglia contribute to sensory signaling in both physiological and pathological states. In vivo sampling from this site may provide important insights into which substances mediate or modulate sensory transmission. To address this possibility, we have applied the microdialysis technique to the guinea pig trigeminal ganglia (TG). The large size and easy access of the TG in the guinea pig make it an ideal sampling site, while the somatotopic organization allows for specific regions of innervation to be studied at the ganglionic level. This report describes the use of microdialysis probes within the TG and use recovery and analysis of substance P (SP) and adenosine triphosphate (ATP) as case in points. Various physiological and pharmacological manipulations can be made, for example release of peptides from ganglionic neurons can be monitored in the presence or absence of inflammation in the orofacial region. Microdialysis performed in the TG thus provides a valuable site for recovery and measurement of a variety of extracellular substances that may be integral in the processing of trigeminal sensory information.
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Affiliation(s)
- John K Neubert
- Pain Neurosensory Mechanisms Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.
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Hu XT, Koeltzow TE, Cooper DC, Robertson GS, White FJ, Vezina P. Repeated ventral tegmental area amphetamine administration alters dopamine D1 receptor signaling in the nucleus accumbens. Synapse 2002; 45:159-70. [PMID: 12112395 DOI: 10.1002/syn.10095] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neuroadaptations of the mesoaccumbens dopamine (DA) system likely underlie the emergence of locomotor sensitization following the repeated intermittent systemic administration of amphetamine (AMPH). In the nucleus accumbens (NAc), such neuroadaptations include enhanced DA overflow in response to a subsequent AMPH challenge as well as increased sensitivity to the inhibitory effects of D1 DA receptor (D1R) activation and an altered profile of D1R-dependent induction of immediate early genes (IEGs). Previous results indicate that AMPH acts in the ventral tegmental area (VTA) to initiate those changes leading to sensitization of the locomotor activity and NAc DA overflow produced by systemic administration of this drug. These observations are intriguing, given that acute infusion of AMPH into the VTA does not stimulate locomotor activity or, as we report presently, increase extracellular NAc DA concentrations. Two experiments, therefore, assessed the ability of repeated VTA AMPH to produce adaptations in D1R signaling in the NAc. Rats were administered three bilateral VTA infusions of saline or AMPH (2.5 microg/0.5 microl/side, one every third day). In the first experiment, in vivo extracellular electrophysiological recordings revealed that previous exposure to VTA AMPH enhanced the sensitivity of NAc neurons to the inhibitory effects of iontophoretic application of the D1R agonist SKF 38393. This effect was observed early (2-3 days) and at 1 month of withdrawal, but not after 2 months. Similarly, in the second experiment it was found that the D1R-dependent induction by AMPH of Fos, FosB, and JunB, but not NGFI-A, in the NAc was enhanced in rats exposed 1 week earlier to repeated VTA AMPH. These findings indicate that repeated VTA AMPH administration initiates relatively long-lasting adaptations in D1R signaling in the NAc that may, together with presynaptic adaptations affecting DA overflow, contribute to the expression of locomotor sensitization by this drug.
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Affiliation(s)
- Xiu-Ti Hu
- Department of Cellular and Molecular Pharmacology Finch University of Health Sciences/The Chicago Medical School, North Chicago, Illinois 60064, USA
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Abstract
Stimulant drugs such as amphetamine are readily self-administered by humans and laboratory animals by virtue of their actions on dopamine (DA) neurons of the midbrain. Repeated exposure to this drug systemically or exclusively in the cell body region of these neurons in the ventral tegmental area (VTA) leads to long-lasting changes in dopaminergic function that can be assessed by increased locomotor activity and enhanced DA overflow in the nucleus accumbens (NAcc) after re-exposure to the drug. Three experiments were conducted to evaluate the possibility that this enduring sensitized reactivity underlies compulsive drug self-administration. In all experiments, rats were pre-exposed to amphetamine and, starting 10 d later, their intravenous self-administration of the drug was assessed. In the first experiment, rats previously exposed to amphetamine systemically or exclusively in the VTA subsequently worked harder than untreated animals to obtain the drug when the work required to obtain successive infusions was increased progressively. In the second experiment, this progressively increasing workload was found to decrease the magnitude of amphetamine-induced DA overflow observed with successive infusions until responding ceased. Rats previously exposed to amphetamine were more resistant to this decline and more apt to maintain responding. Finally, in experiment three, a noncontingent priming injection of the drug produced a greater NAcc DA response and a greater parallel increase in lever pressing in drug compared with saline pre-exposed rats. Together, these results demonstrate a direct relation between drug-induced sensitization of midbrain dopamine neuron reactivity and the excessive pursuit and self-administration of an abused substance.
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Beinfeld MC, Connolly KJ, Pierce RC. Cocaine treatment increases extracellular cholecystokinin (CCK) in the nucleus accumbens shell of awake, freely moving rats, an effect that is enhanced in rats that are behaviorally sensitized to cocaine. J Neurochem 2002; 81:1021-7. [PMID: 12065614 DOI: 10.1046/j.1471-4159.2002.00894.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cholecystokinin (CCK) is co-localized with dopamine, is known to modulate dopamine neurotransmission and is involved in behavioral sensitization to psychostimulants. To better understand its role, CCK was measured by microdialysis in the nucleus accumbens (NAC) shell in response to cocaine in drug-naive rats and in rats that are behaviorally sensitized to cocaine. Basal extracellular levels of CCK in drug-naive rats were 0.17 pg/20 min fraction, while in cocaine-sensitized rats, they were significantly higher (0.56 pg). Treating drug-naive rats with cocaine caused a significant increase in CCK to 0.58 pg. Cocaine treatment of cocaine-sensitized rats increased CCK to 0.98. When analyzed as a function of time after cocaine treatment, these increases were sustained and were significantly different from CCK levels of saline-treated rats. In cocaine-sensitized rats, CCK levels following cocaine treatment were also significantly higher than levels in drug-naive animals receiving a single injection of cocaine. These results provide evidence for an activation of the mesolimbic and/or cerebral cortical CCK system in response to repeated cocaine administration. These results provide a neurochemical basis for an important role of CCK (via modulation of dopamine neurotransmission) in expression of cocaine sensitization.
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Affiliation(s)
- Margery C Beinfeld
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
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Abstract
Microdialysis is a sampling technique allowing measurement of endogenous and exogenous substances in the extracellular fluid surrounding the probe. In vivo microdialysis sampling offers several advantages over conventional methods of studying the pharmacokinetics and metabolism of xenobiotics, both in experimental animals and humans. In the first part of this review article various practical aspects related to blood microdialysis will be discussed, such as: probe design, surgical implantation techniques, methods to determine the in vivo relative recovery of the analyte of interest by the probe, special analytical considerations related to small volume microdialysate samples, and pharmacokinetic calculations based on microdialysis data. In the second part of this review a few selected applications of in vivo microdialysis sampling to investigate pharmacokinetic processes are briefly discussed: determination of in vivo plasma protein binding in small laboratory animals, distribution of drugs across the blood-brain barrier, the use of microdialysis sampling to study biliary excretion and enterohepatic cycling, blood microdialysis sampling in man and in the mouse, and in vivo drug metabolism studies.
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Affiliation(s)
- R K Verbeeck
- Pharmacokinetics and Drug Metabolism Laboratory, School of Pharmacy, PMNT 7369, Université Catholique de Louvain, Av. E. Mounier 73, 1200, Brussels, Belgium.
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Olive MF, Mehmert KK, Hodge CW. Microdialysis in the mouse nucleus accumbens: a method for detection of monoamine and amino acid neurotransmitters with simultaneous assessment of locomotor activity. BRAIN RESEARCH. BRAIN RESEARCH PROTOCOLS 2000; 5:16-24. [PMID: 10719261 DOI: 10.1016/s1385-299x(99)00054-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Microdialysis has been extensively used to characterize the effects of drugs of abuse on extracellular levels of various neurotransmitters in nucleus accumbens (NAc) of the rat brain. However, recent advances in mouse genetics have prompted the need for studying the in vivo neurochemical correlates of drug intake in genetically engineered mice. While an earlier study has shown the feasibility of measuring monoamines in the NAc of behaving transgenic mice [I. Sillaber, A. Montkowski, R. Landgraf, N. Barden, F. Holsboer, R. Spanagel, Enhanced morphine-induced behavioural effects and dopamine release in the nucleus accumbens in a transgenic mouse model of impaired glucocorticoid (type II) receptor function: influence of long-term treatment with the antidepressant moclobemide, Neuroscience, 85 (1998) 415-425 [16] ], in this protocol we demonstrate a method for measuring both monoamine and amino neurotransmitters from the NAc of freely moving mice combined with open field locomotor activity monitoring. Mice were implanted with guide cannulae aimed at the NAc and allowed 4 days of recovery before being implanted with microdialysis probes equipped with 1-mm cuprophane membranes. On the following day, mice were placed in plexiglass chambers equipped with infrared photobeams, where microdialysis samples and locomotor activity data were collected in 10-min intervals. Immediately after collection, microdialysis samples were split into two equal aliquots for separate analysis of monoamine and amino acid neurotransmitter content. High performance liquid chromatography (HPLC) analysis revealed that norepinephrine, dopamine, serotonin, aspartate, glutamate, glycine, taurine, and gamma-aminobutyric acid (GABA) could be detected in each microdialysis sample. Thus, we have shown it is feasible to monitor extracellular levels of multiple neurotransmitters with simultaneous measurement of locomotor behavior in the mouse, making this model suitable for studying differential neurochemical and behavioral responses to drugs of abuse in genetically engineered mice.
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Affiliation(s)
- M F Olive
- Ernest Gallo Clinic and Research Center, Department of Neurology, University of California at San Francisco, San Francisco, CA 94110, USA.
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Lorrain DS, Arnold GM, Vezina P. Previous exposure to amphetamine increases incentive to obtain the drug: long-lasting effects revealed by the progressive ratio schedule. Behav Brain Res 2000; 107:9-19. [PMID: 10628726 DOI: 10.1016/s0166-4328(99)00109-6] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The present experiment tested whether previous exposure to amphetamine would enhance rats' predisposition to self-administer a high dose of the drug under fixed (FR) and progressive ratio (PR) schedules of reinforcement. Rats in different groups were given five injections of either amphetamine (1.5 mg/kg, i.p.) or saline (1.0 ml/kg, i.p.), one injection administered every third day and, starting 10 days later, given the opportunity to lever press for amphetamine (200 microg/kg/infusion, i.v.) on each of several 4 h sessions. When allowed to self-administer up to 10 infusions under first an FR-1 and then an FR-2 schedule, amphetamine and saline pre-exposed rats were indistinguishable and readily acquired the lever press response. However, when tested under the PR schedule of reinforcement, rats previously exposed to amphetamine achieved higher break points than saline pre-exposed rats across six consecutive PR sessions. This difference between groups was long lasting and durable. When compared to saline pre-exposed rats on three separate tests conducted 10, 14 and 21 days following the last PR session, rats pre-exposed to amphetamine also showed (i) greater nucleus accumbens dopamine reactivity to amphetamine (1.0 mg/kg, i.p.), (ii) higher break points when retested on the PR schedule, and (iii) a greater locomotor response to amphetamine (1.0 mg/kg, i.p.). On the last test, both groups showed higher levels of locomotion than no drug control animals that received amphetamine for the first time on this test. These findings suggest that previous exposure to amphetamine produces a long lasting enhancement in the incentive motivation animals will exhibit in their effort to obtain the drug. This enhancement appears to parallel sensitization of the drug's locomotor and nucleus accumbens dopamine activating effects. It may very well be exacerbated by continued exposure to self-administered amphetamine.
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Affiliation(s)
- D S Lorrain
- Department of Psychiatry, The University of Chicago, IL 60637, USA
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