251
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Butt C, Alptekin A, Shippenberg T, Oz M. Endogenous cannabinoid anandamide inhibits nicotinic acetylcholine receptor function in mouse thalamic synaptosomes. J Neurochem 2008; 105:1235-43. [PMID: 18194436 DOI: 10.1111/j.1471-4159.2008.05225.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The effects of the endogenous cannabinoid anandamide [arachidonylethanolamide (AEA)] on the function of nicotinic acetylcholine receptor (nAChR) were investigated using the 86Rb+ efflux assay in thalamic synaptosomes. AEA reversibly inhibited 86Rb+ efflux induced by 300 microM ACh with an IC50 value of 0.9 +/- 2 microM. Pre-treatment with the cannabinoid (CB1) receptor antagonist SR141716A (1 microM), the CB2 receptor antagonist SR144528 (1 microM), or pertussis toxin (0.2 mg/mL) did not alter the inhibitory effects of AEA, suggesting that known CB receptors are not involved in AEA inhibition of nAChRs. AEA inhibition of 86Rb+ efflux was not reversed by increasing acetylcholine (ACh) concentrations. In radioligand binding studies, the specific binding of [3H]-nicotine was not altered in the presence of AEA, indicating that AEA inhibits the function of nAChR in a non-competitive manner. Neither the amidohydrolase inhibitor phenylmethylsulfonyl fluoride (0.2 mM) nor the cyclooxygenase inhibitor, indomethacin, (5 microM) affected AEA inhibition of nAChRs, suggesting that the effect of AEA is not mediated by its metabolic products. Importantly, the extent of AEA inhibition of 86Rb+ efflux was significantly attenuated by the absence of 1% fatty acid free bovine serum albumin pre-treatment, supporting previous findings that fatty acid-like compounds modulate the activity of nAChRs. Collectively, the results indicate that AEA inhibits the function of nAChRs in thalamic synaptosomes via a CB-independent mechanism and that the background activity of these receptors is affected by fatty acids and AEA.
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Affiliation(s)
- Christopher Butt
- Neuroscience Discovery, Martek Biosciences, Boulder, Colorado, USA
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252
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Wüllner U, Gündisch D, Herzog H, Minnerop M, Joe A, Warnecke M, Jessen F, Schütz C, Reinhardt M, Eschner W, Klockgether T, Schmaljohann J. Smoking upregulates α4β2* nicotinic acetylcholine receptors in the human brain. Neurosci Lett 2008; 430:34-7. [DOI: 10.1016/j.neulet.2007.10.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Revised: 08/03/2007] [Accepted: 10/11/2007] [Indexed: 11/26/2022]
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253
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Brunzell DH, Picciotto MR. Molecular mechanisms underlying the motivational effects of nicotine. NEBRASKA SYMPOSIUM ON MOTIVATION. NEBRASKA SYMPOSIUM ON MOTIVATION 2008; 55:17-30. [PMID: 19013937 DOI: 10.1007/978-0-387-78748-0_3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In addition to the primary rewarding properties of nicotine and the alleviation of withdrawal symptoms, cues associated with smoking are critical contributors to maintenance of smoking behavior. Nicotine-paired cues are also critical for precipitating relapse after smoking cessation. An accumulation of evidence suggests that repeated exposure to tobacco, including the primary psychoactive ingredient, nicotine, changes brain neurochemistry in a way that promotes the control that cues associated with smoking or other rewards have over behavior. This chapter will consider the neurochemical mechanisms underlying these neuroadaptations. Targeting these molecular alterations may provide novel treatments for smoking cessation.
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Affiliation(s)
- Darlene H Brunzell
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Richmond, Virginia 23298-0613, USA
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254
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Acosta MC, Eissenberg T, Nichter M, Nichter M, Balster RL. Characterizing early cigarette use episodes in novice smokers. Addict Behav 2008; 33:106-21. [PMID: 17913378 DOI: 10.1016/j.addbeh.2007.09.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Revised: 07/30/2007] [Accepted: 09/05/2007] [Indexed: 01/30/2023]
Abstract
Retrospective self-report data indicate that early cigarette use episodes may be important predictors of smoking. Unfortunately, recall of early experiences are confounded with current smoking. The current study is the first to examine early cigarette use episodes (EUEs) prospectively in novice smokers (less than 15 lifetime cigarettes). Smoking amount, context and subjective experiences for up to five of the first cigarette episodes during their first year of college were collected using weekly internet-based questionnaires and structured interviews. Data were obtained on 538 EUEs from 163 students. EUEs generally occurred within a social/party context; over 90% of EUEs occurred when participants were with other people who were smoking and over 65% occurred while participants were drinking alcohol. Subjective effects across episodes were reported as generally mild and factor analysis yielded Positive, Negative and Sensory/Peripheral effects scales. Subjective effects were related to the amount smoked and inhalation, whereas EUE context, including alcohol use and social context, was not. This study demonstrates that it is possible to study EUEs in college students within days or weeks of their occurrence and that most of these occur in social settings with the concurrent use of alcohol.
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Affiliation(s)
- Michelle C Acosta
- Department of Psychiatry, Columbia University, New York, NY 10025, USA
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255
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Mukhin AG, Mandelkern M, Costello M, Abrams A, Scheibal D, Farahi J, London E, Olmstead R, Rose J, Brody A. Brain nicotinic acetylcholine receptor occupancy: Effect of smoking a de-nicotinized cigarette. Neuroimage 2008. [DOI: 10.1016/j.neuroimage.2008.04.224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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256
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Picciotto MR, Addy NA, Mineur YS, Brunzell DH. It is not "either/or": activation and desensitization of nicotinic acetylcholine receptors both contribute to behaviors related to nicotine addiction and mood. Prog Neurobiol 2007; 84:329-42. [PMID: 18242816 DOI: 10.1016/j.pneurobio.2007.12.005] [Citation(s) in RCA: 303] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 11/19/2007] [Accepted: 12/18/2007] [Indexed: 10/22/2022]
Abstract
Nicotine can both activate and desensitize/inactivate nicotinic acetylcholine receptors (nAChRs). An ongoing controversy in the field is to what extent the behavioral effects of nicotine result from activation of nAChRs, and to what extent receptor desensitization is involved in these behavioral processes. Recent electrophysiological studies have shown that both nAChR activation and desensitization contribute to the effects of nicotine in the brain, and these experiments have provided cellular mechanisms that could underlie the contribution of both these processes to nicotine-mediated behaviors. For instance, desensitization of nAChRs may contribute to the salience of environmental cues associated with smoking behavior and activation and desensitization of nAChRs may contribute to both primary and conditioned drug reward. Similarly, studies of the antidepressant-like effects of nicotinic agents have revealed a balance between activation and desensitization of nAChRs. This review will examine the evidence for the contribution of these two very different consequences of nicotine administration to behaviors related to nicotine addiction, including processes related to drug reinforcement and affective modulation. We conclude that there are effects of nAChR activation and desensitization on drug reinforcement and affective behavior, and that both processes are important in the behavioral consequences of nicotine in tobacco smoking.
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Affiliation(s)
- Marina R Picciotto
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06508, USA.
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257
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Chefer SI, Pavlova OA, Zhang Y, Vaupel DB, Kimes AS, Horti AG, Stein E, Mukhin AG. NIDA522131, a new radioligand for imaging extrathalamic nicotinic acetylcholine receptors: in vitro and in vivo evaluation. J Neurochem 2007; 104:306-15. [PMID: 17986233 DOI: 10.1111/j.1471-4159.2007.05009.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel radioligand, 6-chloro-3-((2-(S)-azetidinyl)methoxy)-5-(2-fluoropyridin-4-yl)pyridine (NIDA522131), for imaging extrathalamic nicotinic acetylcholine receptors (nAChRs) was characterized in vitro and in vivo using positron emission tomography. The K(d) and T(1/2) of dissociation of NIDA522131 binding measured at 37 degrees C in vitro were 4.9 +/- 0.4 pmol/L and 81 +/- 5 min, respectively. The patterns of radioactivity distribution in monkey brain in vivo was similar to that of 2-[(18)F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (2FA), a radioligand that has been successfully used in humans, and matched the alpha(4)beta(2)* nAChRs distribution. Comparison between [(18)F]NIDA522131 and 2FA demonstrated better in vivo binding properties of the new radioligand and substantially greater radioactivity accumulation in brain. Consistent with [(18)F]NIDA522131 elevated affinity for nAChRs and its increased lipophilicity, both, the total and non-displaceable distribution volumes were substantially higher than those of 2FA. Estimated binding potential values in different brain regions, characterizing the specificity of receptor binding, were 3-4 fold higher for [(18)F]NIDA522131 than those of 2FA. Pharmacological evaluation in mice demonstrated a toxicity that was comparable to 2FA and is in agreement with a 2300 fold higher affinity at alpha(4)beta(2)* versus alpha(3)beta(4)* nAChRs. These results suggest that [(18)F]NIDA522131 is a promising positron emission tomography radioligand for studying extrathalamic nAChR in humans.
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Affiliation(s)
- Svetlana I Chefer
- Neuroimaging Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institute of Health, Department of Health and Human Services, Baltimore, Maryland, USA
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258
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Domier CP, Monterosso JR, Brody AL, Simon SL, Mendrek A, Olmstead R, Jarvik ME, Cohen MS, London ED. Effects of cigarette smoking and abstinence on Stroop task performance. Psychopharmacology (Berl) 2007; 195:1-9. [PMID: 17634928 PMCID: PMC2796691 DOI: 10.1007/s00213-007-0869-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Accepted: 06/21/2007] [Indexed: 11/25/2022]
Abstract
RATIONALE Smokers report enhanced concentration after cigarette smoking and difficulty concentrating when abstinent from smoking. These perceived effects may contribute to smoking cessation failures, and if so, clarification of their cognitive bases could inform treatment strategies. Selective attention may be important in this regard, but earlier literature presents inconsistent findings on how smoking abstinence and resumption of smoking influence this cognitive function. OBJECTIVES We aimed to compare smokers and nonsmokers on selective attention, and in smokers, to test the effects of overnight abstinence from smoking and of acute smoking on selective attention. MATERIALS AND METHODS Smokers and nonsmokers (n = 43) performed a Stroop test (two test days, two test blocks per day). Smokers participated after overnight abstinence and also within 1-h of ad libitum smoking. Smokers each smoked a cigarette between test blocks on each day; nonsmokers did not. RESULTS Smokers demonstrated longer response latencies for both congruent and incongruent stimuli after overnight than brief abstinence, but no deficit specifically related to selective attention. Whereas nonsmokers showed no changes in performance in the second test block, smoking between blocks reduced the Stroop effect when smokers were abstinent overnight. CONCLUSIONS These data are consistent with the hypothesis that abstinence from smoking among nicotine-dependent individuals has deleterious effects on cognitive performance, but do not indicate that selective attention is adversely effected. Improvement in selective attention after terminating abstinence with one cigarette may also contribute to smokers' perceived enhanced ability to concentrate after smoking.
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Affiliation(s)
- Catherine P Domier
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, Los Angeles, CA, USA
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259
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Kimes AS, Chefer SI, Matochik JA, Contoreggi CS, Vaupel DB, Stein EA, Mukhin AG. Quantification of nicotinic acetylcholine receptors in the human brain with PET: bolus plus infusion administration of 2-[18F]F-A85380. Neuroimage 2007; 39:717-27. [PMID: 17962044 DOI: 10.1016/j.neuroimage.2007.09.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 08/16/2007] [Accepted: 09/03/2007] [Indexed: 12/01/2022] Open
Abstract
Quantitative analysis of most positron emission tomography (PET) data requires arterial blood sampling and dynamic scanning when the radioligand is administered as a bolus injection. Less invasive studies can be accomplished if the radioligand is administered as a bolus plus constant infusion (B/I). The purpose of the current study was to evaluate a B/I paradigm for quantifying high affinity nicotinic acetylcholine receptors (nAChRs) with PET and 2-[(18)F]F-A85380 (2FA). Seven volunteers underwent a study in which 2FA was administered as a bolus injection and another study in which the 2FA was administered by B/I (Kbolus=500 min). We evaluated the feasibility of using scans of a 2 h duration starting 6 h after the start of the 2FA administration and data from venous blood. Radioactivity in the brain and in arterial and venous plasma reached steady state by 6 h. Volumes of distribution (V(T)) calculated from the ratio of radioactivity in the brain areas of interest to the radioactivity corresponding to unbound, unmetabolized 2FA in venous plasma at steady state in the B/I studies were very similar to those calculated from time activity curves of unbound, unmetabolized 2FA in arterial plasma and regional brain radioactivity from 8-h dynamic scans after bolus administration of 2FA. The results of repeated PET studies with 2FA showed a high reproducibility of V(T) measurements. We conclude that B/I methodology will be useful for clinical and research studies of brain nAChRs.
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Affiliation(s)
- Alane S Kimes
- Neuroimaging Research Branch, NIDA IRP/NIH/DHHS, Baltimore, MD 21224, USA
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260
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Rose JE. Multiple brain pathways and receptors underlying tobacco addiction. Biochem Pharmacol 2007; 74:1263-70. [PMID: 17826746 DOI: 10.1016/j.bcp.2007.07.039] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 07/26/2007] [Accepted: 07/26/2007] [Indexed: 01/16/2023]
Abstract
Over the last 20 years much progress has been made in understanding the pharmacologic basis of tobacco addiction. In particular, the role of nicotine in reinforcing smoking behavior has been studied from a variety of perspectives. This article discusses two important aspects of this topic: (1) brain pathways underlying tobacco addiction; and (2) the actions of nicotine at nicotinic cholinergic receptors. Recent evidence will be reviewed indicating that nicotine reinforces smoking behavior by acting on more than one subtype of nicotinic receptor. Similarly, the role of several brain pathways in tobacco addiction will be considered. Tobacco addiction may thus be seen as a complex neuropsychopharmacological disorder; further progress in smoking cessation treatment may require that we address the multiple molecular and brain components of this addiction.
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Affiliation(s)
- Jed E Rose
- Center for Nicotine and Smoking Cessation Research, Duke University Medical Center, Durham, NC 27705, USA.
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261
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Severance EG, Yolken RH. Lack of RIC-3 congruence with β2 subunit-containing nicotinic acetylcholine receptors in bipolar disorder. Neuroscience 2007; 148:454-60. [PMID: 17640815 DOI: 10.1016/j.neuroscience.2007.06.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 06/07/2007] [Accepted: 06/11/2007] [Indexed: 11/29/2022]
Abstract
Nicotinic acetylcholine receptor (nAChR) dysfunction occurs in individuals with schizophrenia (SZ) and may also affect individuals with bipolar disorder (BP). The molecular mechanisms for these disease-associated cholinergic deficits are not known. In vitro, the protein RIC-3 (resistance to inhibitors of cholinesterase-3) aids the assembly and trafficking of alpha7-nAChRs but has unclear action on the biogenesis of alpha4/beta2-nAChRs. To evaluate RIC-3/nAChR dynamics in diseased and normal human brain tissue, we measured RIC-3, alpha7-, alpha4- and beta2-nAChRs transcript levels in postmortem prefrontal cortex of individuals with SZ (n=31), BP (n=28) and unaffected controls (NC, n=33). Of the 28 individuals with BP, 20 had a history of psychotic symptoms. We compared relative message abundances between diagnostic groups and tested correlations of RIC-3 with each nAChR message subtype. RIC-3 and alpha4 messages were significantly increased in BP compared with NC (RIC-3, P< or =0.002; alpha4, P< or =0.04). RIC-3 message was also upregulated in SZ (P< or =0.04). In BP with psychoses, RIC-3 and alpha4 levels were increased compared with BP without psychoses (both P< or =0.02) and compared with NC (RIC-3, P< or =0.0003; alpha4, P< or =0.004). In correlation regression analyses, RIC-3 expression was very highly correlated to alpha7, alpha4 and beta2 in NC (alpha7, P< or =2.5e-05; alpha4, P< or =2.5e-09; beta2, P< or =0.003) and in SZ (alpha7, P< or =1e-07; alpha4, P< or =7e-07; beta2, P< or =3e-09). RIC-3 also strongly correlated with alpha7 and alpha4 in BP (alpha7, P< or =0.003; alpha4, P< or =3.5e-07). RIC-3 was modestly correlated with beta2 in BP overall (P< or =0.04), but showed no significant correlation in BP with psychoses (P< or =0.31) compared with a significant correlation in BP without psychoses (P< or =0.007). In conclusion, coordinated RIC-3/alpha4 upregulation and discordant RIC-3/beta2 levels suggest that alpha4/beta2 nAChR deficits in BP may occur from dysregulated RIC-3 chaperoning of the beta2 nAChR subunit in a subset of patients affected by psychotic features.
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Affiliation(s)
- E G Severance
- Stanley Division of Developmental Neurovirology, Department of Pediatrics, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Blalock 1105, Baltimore, MD 21287-4933, USA.
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262
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Shumway DA, Pavlova OA, Mukhin AG. A simplified method for the measurement of nonmetabolized 2-[18F]F-A-85380 in blood plasma using solid-phase extraction. Nucl Med Biol 2007; 34:221-8. [PMID: 17307130 DOI: 10.1016/j.nucmedbio.2006.12.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2006] [Revised: 11/02/2006] [Accepted: 12/05/2006] [Indexed: 11/29/2022]
Abstract
Quantification of alpha(4)beta(2)* nicotinic acetylcholine receptors using 2-[(18)F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (2-[(18)F]FA) and positron emission tomography (PET) imaging requires measurement of nonmetabolized radioligand in blood plasma, which was previously accomplished using high-performance liquid chromatography (HPLC). Here, we introduce a one-step solid-phase extraction (SPE) method for measuring the concentration of nonmetabolized 2-[(18)F]FA. This method allows many samples to be processed in a short period of time. SPE effectively separated 2-[(18)F]FA from radioactive metabolites typically observed in blood plasma after administration of radioligand in humans. Measurements of the 2-[(18)F]FA parent fraction in healthy human volunteers obtained using the SPE method were nearly identical to those obtained using HPLC (1.3+/-5% average underestimation of SPE), and reproducibility was good within and between runs (2% and 6% coefficient of variation, respectively). SPE recovery of 2-[(18)F]FA from blood plasma was not appreciably diminished (3+/-0.6%) by a larger volume of blood plasma loaded onto the cartridge, suggesting the possibility of increasing the plasma sample volume at later times in a PET study to improve measurement sensitivity. 2-[(18)F]FA was stable in blood stored on ice over 8 h and in saline at low concentrations (<2 MBq/ml) but not at high concentrations (ca. 130 MBq/ml). Using SPE, the elimination half-life and full body distribution volume of 2-[(18)F]FA in healthy human volunteers were estimated as 4.2+/-0.8 h and 220+/-70 L, respectively. These results suggest that SPE is the method of choice for the determination of the plasma 2-[(18)F]FA concentration when measurement of individual metabolites is not required.
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Affiliation(s)
- Dean A Shumway
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, NIH, DHHS, Baltimore, MD 21224, USA
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263
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Spivak CE, Lupica CR, Oz M. The Endocannabinoid Anandamide Inhibits the Function of α4β2 Nicotinic Acetylcholine Receptors. Mol Pharmacol 2007; 72:1024-32. [PMID: 17628012 DOI: 10.1124/mol.107.036939] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The effects of the endocannabinoid anandamide (arachidonylethanolamide, AEA) on the function of alpha4beta2 nicotinic acetylcholine receptors (nAChR) stably expressed in SH-EP1 cells were investigated using the whole-cell patch-clamp technique. In the concentration range of 200 nM to 2 microM, AEA significantly reduced the maximal amplitudes and increased the desensitization of acetylcholine (ACh)-induced currents. The effects of AEA could be neither replicated by the exogenous cannabinoid Delta(9)-tetrahydrocannabinol (1 microM) nor reversed by the selective CB1 receptor antagonist 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide (SR-141716A) (1 microM). The actions of AEA were apparent when applied extracellularly but not during intracellular dialysis. Furthermore, the effects of AEA ACh currents were not altered by the calcium chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. The onset and washout of the AEA effects required several minutes (10-30 min), but the latter was significantly decreased in the presence of lipid-free bovine serum albumin (BSA). Moreover, BSA alone increased peak ACh current amplitudes and diminished desensitization rates in naive cells, suggesting a tonic modulation of alpha4beta2 nAChR function by an endogenous AEA-like lipid. Further analysis of AEA effects on alpha4beta2 nAChR-mediated currents, using a two-stage desensitization model, indicated that the first forward rate constant leading to desensitization, k(1), increased nearly 30-fold as a linear function of the AEA concentration. In contrast, the observation that the other three rate constants were unaltered by AEA suggested that AEA raised the energy of the activated state. These results indicate that AEA directly inhibits the function of alpha4beta2 nAChRs in a CB1 receptor-independent manner.
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Affiliation(s)
- Charles E Spivak
- National Institute on Drug Abuse, Intramural Research Program, Cellular Neurobiology Branch, Electrophysiology Unit, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA.
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264
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Xu J, Mendrek A, Cohen MS, Monterosso J, Simon S, Jarvik M, Olmstead R, Brody AL, Ernst M, London ED. Effect of cigarette smoking on prefrontal cortical function in nondeprived smokers performing the Stroop Task. Neuropsychopharmacology 2007; 32:1421-8. [PMID: 17164821 PMCID: PMC2876092 DOI: 10.1038/sj.npp.1301272] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Some reports indicate that cigarette smoking can help smokers focus attention, even when they have not abstained from smoking for a substantial period of time (eg, >1 h). Understanding the mechanisms by which smoking affects attention may help in designing smoking cessation treatments. Thirteen nonsmokers and nine smokers participated in two tests of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). During fMRI, the participants performed the Stroop Task. There was a 15-min break between the two tests. During the break, each smoker smoked one cigarette. For smokers, the first test began 45-60 min after the last cigarette of ad libitum smoking. The differences in BOLD signal changes between Stroop conditions (ie, incongruent minus congruent) showed a group x test interaction in the right precentral sulcus, including the putative human frontal eye field (FEF). Smokers, but not nonsmokers, showed greater changes (relative to rest) in BOLD signal in the incongruent than in the congruent condition in the first fMRI test but not in the second. Even after brief abstinence from smoking, therefore, smokers exhibit compromised functional efficiency in the right FEF and adjacent precentral sulcus in a test of selective attention; and smoking ameliorates this condition.
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Affiliation(s)
- Jiansong Xu
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Adrianna Mendrek
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Mark S Cohen
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Neurology, Radiological Sciences, and Biomedical Physics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - John Monterosso
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Sara Simon
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Murray Jarvik
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Richard Olmstead
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Arthur L Brody
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Monique Ernst
- Mood and Anxiety Disorders Program, National Institute of Mental Health, Bethesda, MD, USA
| | - Edythe D London
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Correspondence: Dr ED London, NPI-Semel Institute for Neuroscience, University of California Los Angeles, 760 Westwood Plaza, C8-528, Los Angeles, CA 90024, USA, Tel: + 1 310 825 0606, Fax: + 1 310 825 0812,
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265
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Vaupel DB, Stein EA, Mukhin AG. Quantification of alpha4beta2* nicotinic receptors in the rat brain with microPET and 2-[18F]F-A-85380. Neuroimage 2007; 34:1352-62. [PMID: 17187994 PMCID: PMC2023973 DOI: 10.1016/j.neuroimage.2006.10.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 09/27/2006] [Accepted: 10/13/2006] [Indexed: 11/17/2022] Open
Abstract
The radioligand 2-[(18)F]F-A-85380 has been used for PET studies of the alpha4beta2* subtype of nicotinic acetylcholine receptors (nAChRs) in the living brain of humans and nonhuman primates. In order to extend the capacity of microPET to quantify neuroreceptors in rat brain, we carried out studies of 2-[(18)F]F-A-85380 to measure the apparent binding potential BP* in individual rats, which were studied repeatedly over several months. Using a bolus-plus-infusion paradigm, 2-[(18)F]F-A-85380 (specific activity 20-1300 GBq/micromol) was administered intravenously over 8 to 9 h with K(bol) values of 350 to 440 min and a mean infusion rate of 0.03+/-0.01 nmol/kg/h. Studies included a 2-h nicotine infusion initiated 2 h before the end of scanning to displace specifically bound radioactivity. Steady state binding in brain was obtained within 5 h as defined by the occurrence of constant radioactivity concentrations in brain regions and constant, free arterial plasma levels of nonmetabolized radioligand. BP* averages (+/-SEM) for thalamus, forebrain, and cerebellum were 5.9+/-0.7, 2.6+/-0.4, and 1.0+/-0.1, respectively, which are consistent with the alpha4beta2* nAChR distribution in rat brain measured in vitro. Studies of receptor occupancy determined the ED(50) to be 0.29 nmol/kg/h. The demonstration that alpha4beta2* nAChRs are quantifiable in the rat brain using PET measurements, coupled with the ability to conduct longitudinal studies over several months in the same rats, suggests potential applications to studies of chronic nicotine use, its treatment, and abnormal functioning of alpha4beta2* receptors in a rat model.
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Affiliation(s)
- D Bruce Vaupel
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA.
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Pimlott SL, Piggott M, Patterson J, Cavanagh J, Wyper DJ. SPECT imaging of the α4β2 nicotinic receptor using [5-123I]A85380. J Labelled Comp Radiopharm 2007. [DOI: 10.1002/jlcr.1192] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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268
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Esposito G, Giovacchini G, Der M, Liow JS, Bhattacharjee AK, Ma K, Herscovitch P, Channing M, Eckelman WC, Hallett M, Carson RE, Rapoport SI. Imaging signal transduction via arachidonic acid in the human brain during visual stimulation, by means of positron emission tomography. Neuroimage 2006; 34:1342-51. [PMID: 17196833 PMCID: PMC2040045 DOI: 10.1016/j.neuroimage.2006.11.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 10/20/2006] [Accepted: 11/01/2006] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Arachidonic acid (AA, 20:4n-6), an important second messenger, is released from membrane phospholipid following receptor mediated activation of phospholipase A(2) (PLA(2)). This signaling process can be imaged in brain as a regional brain AA incorporation coefficient K*. HYPOTHESIS K* will be increased in brain visual areas of subjects submitted to visual stimulation. SUBJECTS AND METHODS Regional values of K* were measured with positron emission tomography (PET), following the intravenous injection of [1-(11)C]AA, in 16 healthy volunteers subjected to visual stimulation at flash frequencies 2.9 Hz (8 subjects) or 7.8 Hz (8 subjects), compared with the dark (0 Hz) condition. Regional cerebral blood flow (rCBF) was measured with intravenous [(15)O]water under comparable conditions. RESULTS During flash stimulation at 2.9 Hz or 7.8 Hz vs. 0 Hz, K* was increased significantly by 2.3-8.9% in Brodmann areas 17, 18 and 19, and in additional frontal, parietal and temporal cortical regions. rCBF was increased significantly by 3.1-22%, often in comparable regions. Increments at 7.8 Hz often exceeded those at 2.9 Hz for both K* and rCBF. Decrements in both parameters also were produced, particularly in frontal brain regions. CONCLUSIONS AA plays a role in signaling processes provoked by visual stimulation, since visual stimulation at flash frequencies of 2.9 and 7.8 Hz compared to 0 Hz modifies both K* for AA and rCBF in visual and related areas of the human brain. The two-stimulus condition paradigm of this study might be used with PET to image effects of other functional activations and of drugs on brain signaling via AA.
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Affiliation(s)
- Giuseppe Esposito
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
| | - Giampiero Giovacchini
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
- Department of Radiology, University of Pisa, Pisa, Italy
| | - Margaret Der
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
| | - Jeih-San Liow
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
| | - Abesh K. Bhattacharjee
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
| | - Kaizong Ma
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
| | - Peter Herscovitch
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
| | - Michael Channing
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
| | - William C. Eckelman
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
- Molecular Tracer, LLC, Snow Point Drive, Bethesda MD
| | - Mark Hallett
- Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disease and Stroke; National Institutes of Health, Bethesda, MD
| | - Richard E. Carson
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
- Department of Diagnostic Radiology and Biomedical Engineering, Yale University, New Haven, CT
| | - Stanley I. Rapoport
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
- *Corresponding Author: Brain Physiology and Metabolism Section, Bldg. 9, Rm. 1S128, National Institute on Aging, National Institutes of Health, 9 Memorial Drive, Bethesda, MD 20892, Tel: 301 496 1765, Fax: 301 402 0074, E-mail:
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Xiao Y, Fan H, Musachio JL, Wei ZL, Chellappan SK, Kozikowski AP, Kellar KJ. Sazetidine-A, a novel ligand that desensitizes alpha4beta2 nicotinic acetylcholine receptors without activating them. Mol Pharmacol 2006; 70:1454-60. [PMID: 16857741 DOI: 10.1124/mol.106.027318] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels found throughout the central and peripheral nervous systems. They are crucial to normal physiology and have been clearly implicated in nicotine addiction. In addition, they are possible therapeutic targets in a wide range of pathological conditions, including cognitive disorders, Parkinson's disease, and neuropathic pain. Nicotinic ligands are usually classified as agonists (or partial agonists), competitive antagonists, or noncompetitive antagonists. Sazetidine-A is a new nicotinic ligand that shows a different pharmacological profile from any of these known classes of ligands. Sazetidine-A competes with very high binding affinity (Ki approximately 0.5 nM) and selectivity for the alpha4beta2 nAChR subtype (Ki ratio alpha3beta4/alpha4beta2 approximately 24,000). Despite its high affinity, sazetidine-A neither activates nAChR channel function nor prevents channel activation when it is applied simultaneously with nicotine. However, when it is pre-incubated for 10 min with the receptors, it potently blocks nicotine-stimulated alpha4beta2 nAChR function (IC50 approximately 30 nM). The action of sazetidine-A may be explained by its very low affinity for the resting conformation of the alpha4beta2 nAChRs, and its very high affinity for the desensitized state of the receptor. We propose that sazetidine-A is a "silent desensitizer" of nAChRs, meaning that it desensitizes the receptor without first activating it. Furthermore, comparison of the effects of sazetidine-A and nicotine at alpha4beta2 nAChRs suggests that the predominant effects of nicotine and other nicotinic agonists are related to desensitization of the receptors and that sazetidine-A potently mimics these effects.
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Affiliation(s)
- Yingxian Xiao
- Department of Pharmacology, Georgetown University School of Medicine, Washington, DC 20057, USA
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Davis TJ, de Fiebre CM. Alcohol's actions on neuronal nicotinic acetylcholine receptors. ALCOHOL RESEARCH & HEALTH : THE JOURNAL OF THE NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM 2006; 29:179-85. [PMID: 17373406 PMCID: PMC6527039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Although it has been known for many years that alcoholism and tobacco addiction often co-occur, relatively little information is available on the biological factors that regulate the co-use and abuse of nicotine and alcohol. In the brain, nicotine acts at several different types of receptors collectively known as nicotinic acetylcholine receptors (nAChRs). Alcohol also acts on at least some of these receptors, enhancing the function of some nAChR subtypes and inhibiting the activity of others. Chronic alcohol and nicotine administration also lead to changes in the numbers of nAChRs. Natural variations (i.e., polymorphisms) in the genes encoding different nAChR subunits may be associated with individual differences in the sensitivity to some of alcohol's and nicotine's effects. Finally, at least one subtype of nAChR may help protect cells against alcohol-induced neurotoxicity.
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Affiliation(s)
- Tiffany J Davis
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
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