Skip to content
naulon

No retraction, correction or concern found when last checked on Nov 1, 2026.

Clozapine N-Oxide Administration Produces Behavioral Effects in Long–Evans Rats: Implications for Designing DREADD Experiments

Duncan A. A. MacLaren, Richard W. Browne, Jessica K. Shaw and 4 more

eneuro · 2016 · CC BY-NC-SA

doi:10.1523/eneuro.0219-16.2016

Abstract

Clozapine N-oxide (CNO) is a ligand for a powerful chemogenetic system that can selectively inhibit or activate neurons; the so-called Designer Receptors Exclusively Activated by Designer Drugs (DREADD) system. This system consists of synthetic G-protein-coupled receptors, which are not believed to be activated by any endogenous ligand, but are activated by the otherwise inert CNO. However, it has previously been shown that the administration of CNO in humans and rats leads to detectable levels of the bioactive compounds clozapine and N -desmethylclozapine ( N -Des). As a follow-up, experiments were conducted to investigate the effects of CNO in male Long–Evans rats. It was found that 1 mg/kg CNO reduced the acoustic startle reflex but had no effect on prepulse inhibition (PPI; a measure of sensorimotor gating). CNO (2 and 5 mg/kg) had no effect on the disruption to PPI induced by the NMDA antagonist phencyclidine or the muscarinic antagonist scopolamine. In locomotor studies, CNO alone (at 1, 2, and 5 mg/kg) had no effect on spontaneous locomotion, but 5 mg/kg CNO pretreatment significantly attenuated d -amphetamine-induced hyperlocomotion. In line with the behavioral results, fast-scan cyclic voltammetry found that 5 mg/kg CNO significantly attenuated the d -amphetamine-induced increase in evoked dopamine. However, the effects seen after CNO administration cannot be definitively ascribed to CNO because biologically relevant levels of clozapine and N -Des were found in plasma after CNO injection. Our results show that CNO has multiple dose-dependent effects in vivo and is converted to clozapine and N -Des emphasizing the need for a CNO-only DREADD-free control group when designing DREADD-based experiments.

Shown for reading. Its publisher allows quoting it, not republishing it.

References 63

  1. 1.

    Agulhon C, Boyt KM, Xie AX, Friocourt F, Roth BL, McCarthy KD (2013 ) Modulation of the autonomic nervous system and behaviour by acute glial cell Gq protein-coupled receptor activation in vivo. J Physiol 591:5599–5609.

    Not in our library10.1113/jphysiol.2013.261289

  2. 2.

    Alexander GM, Rogan SC, Abbas AI, Armbruster BN, Pei Y, Allen JA, Nonneman RJ, Hartmann J, Moy SS, Nicolelis MA, McNamara JO, Roth BL (2009 ) Remote control of neuronal activity in transgenic mice expressing evolved G protein-coupled receptors. Neuron 63:27–39.

    Not in our library10.1016/j.neuron.2009.06.014

  3. 3.

    Alves-Rodrigues A, Leurs R, Willems E, Timmerman H (1996 ) Binding of clozapine metabolites and analogues to the histamine H3 receptor in rat brain cortex. Arch Pharm (Weinheim) 329:413–416.

    Not in our library10.1002/ardp.19963290808

  4. 4.

    Anderson SA, Michaelides M, Zarnegar P, Ren Y, Fagergren P, Thanos PK, Wang GJ, Bannon M, Neumaier JF, Keller E, Volkow ND, Hurd YL (2013 ) Impaired periamygdaloid-cortex prodynorphin is characteristic of opiate addiction and depression. J Clin Invest 123:5334–5341.

    Not in our library10.1172/jci70395

  5. 5.

    Armbruster BN, Li X, Pausch MH, Herlitze S, Roth BL (2007 ) Evolving the lock to fit the key to create a family of G protein-coupled receptors potently activated by an inert ligand. Proc Natl Acad Sci U S A 104:5163–5168.

    Not in our library10.1073/pnas.0700293104

  6. 6.

    Baldessarini RJ, Centorrino F, Flood JG, Volpicelli SA, Huston-Lyons D, Cohen BM (1993 ) Tissue concentrations of clozapine and its metabolites in the rat. Neuropsychopharmacology 9:117–124.

    Not in our library10.1038/npp.1993.50

  7. 7.

    Boender AJ, de Jong JW, Boekhoudt L, Luijendijk MC, van der Plasse G, Adan RA (2014 ) Combined use of the canine adenovirus-2 and DREADD-technology to activate specific neural pathways in vivo. PLoS One 9:e95392.

    Not in our library10.1371/journal.pone.0095392

  8. 8.

    Bull C, Freitas KC, Zou S, Poland RS, Syed WA, Urban DJ, Minter SC, Shelton KL, Hauser KF, Negus SS, Knapp PE, Bowers MS (2014 ) Rat nucleus accumbens core astrocytes modulate reward and the motivation to self-administer ethanol after abstinence. Neuropsychopharmacology 39:2835–2845.

    Not in our library10.1038/npp.2014.135

  9. 9.

    Bun H, Disdier B, Aubert C, Catalin J (1999 ) Interspecies variability and drug interactions of clozapine metabolism by microsomes. Fundam Clin Pharmacol 13:577–581.

    Not in our library10.1111/j.1472-8206.1999.tb00364.x

  10. 10.

    Chang SE, Todd TP, Bucci DJ, Smith KS (2015 ) Chemogenetic manipulation of ventral pallidal neurons impairs acquisition of sign-tracking in rats. Eur J Neurosci 42:3105–3116.

    Not in our library10.1111/ejn.13103

  11. 11.

    Chang WH, Lin SK, Lane HY, Wei FC, Hu WH, Lam YW, Jann MW (1998 ) Reversible metabolism of clozapine and clozapine N-oxide in schizophrenic patients. Prog Neuropsychopharmacol Biol Psychiatry 22:723–739.

    Not in our library10.1016/s0278-5846(98)00035-9

  12. 12.

    Chen X, Choo H, Huang XP, Yang X, Stone O, Roth BL, Jin J (2015 ) The first structure-activity relationship studies for designer receptors exclusively activated by designer drugs. ACS Chem Neurosci 6:476–484.

    Not in our library10.1021/cn500325v

  13. 13.

    Conti LH, Costill JE, Flynn S, Tayler JE (2005 ) Effects of a typical and an atypical antipsychotic on the disruption of prepulse inhibition caused by corticotropin-releasing factor and by rat strain. Behav Neurosci 119:1052–1060.

    Not in our library10.1037/0735-7044.119.4.1052

  14. 14.

    Coward DM (1992 ) General pharmacology of clozapine. Br J Psychiatry Suppl (17):5–11.

    Not in our library

  15. 15.

    Coward P, Wada HG, Falk MS, Chan SD, Meng F, Akil H, Conklin BR (1998 ) Controlling signaling with a specifically designed Gi-coupled receptor. Proc Natl Acad Sci U S A 95:352–357.

    Not in our library10.1073/pnas.95.1.352

  16. 16.

    Cremers TI, Flik G, Hofland C, Stratford RE Jr. (2012 ) Microdialysis evaluation of clozapine and N-desmethylclozapine pharmacokinetics in rat brain. Drug Metab Dispos 40:1909–1916.

    Not in our library10.1124/dmd.112.045682

  17. 17.

    Davies MA, Compton-Toth BA, Hufeisen SJ, Meltzer HY, Roth BL (2005 ) The highly efficacious actions of N-desmethylclozapine at muscarinic receptors are unique and not a common property of either typical or atypical antipsychotic drugs: is M1 agonism a pre-requisite for mimicking clozapine's actions?. Psychopharmacology (Berl) 178:451–460.

    Not in our library10.1007/s00213-004-2017-1

  18. 18.

    Dell’Anno MT, Caiazzo M, Leo D, Dvoretskova E, Medrihan L, Colasante G, Giannelli S, Theka I, Russo G, Mus L, Pezzoli G, Gainetdinov RR, Benfenati F, Taverna S, Dityatev A, Broccoli V (2014 ) Remote control of induced dopaminergic neurons in parkinsonian rats. J Clin Invest 124:3215–3229.

    Not in our library10.1172/jci74664

  19. 19.

    España RA, Oleson EB, Locke JL, Brookshire BR, Roberts DC, Jones SR (2010 ) The hypocretin-orexin system regulates cocaine self-administration via actions on the mesolimbic dopamine system. Eur J Neurosci 31:336–348.

    Not in our library10.1111/j.1460-9568.2009.07065.x

  20. 20.

    España RA, Melchior JR, Roberts DC, Jones SR (2011 ) Hypocretin 1/orexin A in the ventral tegmental area enhances dopamine responses to cocaine and promotes cocaine self-administration. Psychopharmacology 214:415–426.

    Not in our library10.1007/s00213-010-2048-8

  21. 21.

    Farrell MS, Pei Y, Wan Y, Yadav PN, Daigle TL, Urban DJ, Lee HM, Sciaky N, Simmons A, Nonneman RJ, Huang XP, Hufeisen SJ, Guettier JM, Moy SS, Wess J, Caron MG, Calakos N, Roth BL (2013 ) A Gαs DREADD mouse for selective modulation of cAMP production in striatopallidal neurons. Neuropsychopharmacology 38:854–862.

    Not in our library10.1038/npp.2012.251

  22. 22.

    Feifel D, Shilling PD, Melendez G (2011 ) Clozapine and PD149163 elevate prepulse inhibition in Brown Norway rats. Behav Neurosci 125:268–272.

    Not in our library10.1037/a0022691

  23. 23.

    Ferguson SM, Eskenazi D, Ishikawa M, Wanat MJ, Phillips PE, Dong Y, Roth BL, Neumaier JF (2011 ) Transient neuronal inhibition reveals opposing roles of indirect and direct pathways in sensitization. Nat Neurosci 14:22–24.

    Not in our library10.1038/nn.2703

  24. 24.

    Ferguson SM, Phillips PE, Roth BL, Wess J, Neumaier JF (2013 ) Direct-pathway striatal neurons regulate the retention of decision-making strategies. J Neurosci 33:11668–11676.

    Not in our library10.1523/jneurosci.4783-12.2013

  25. 25.
  26. 26.

    Grace PM, Strand KA, Galer EL, Urban DJ, Wang X, Baratta MV, Fabisiak TJ, Anderson ND, Cheng K, Greene LI, Berkelhammer D, Zhang Y, Ellis AL, Yin HH, Campeau S, Rice KC, Roth BL, Maier SF, Watkins LR (2016 ) Morphine paradoxically prolongs neuropathic pain in rats by amplifying spinal NLRP3 inflammasome activation. Proc Natl Acad Sci U S A 113:E3441–E3450.

    Not in our library10.1073/pnas.1602070113

  27. 27.

    Guettier JM, Gautam D, Scarselli M, Ruiz de Azua I, Li JH, Rosemond E, Ma X, Gonzalez FJ, Armbruster BN, Lu H, Roth BL, Wess J (2009 ) A chemical-genetic approach to study G protein regulation of beta cell function in vivo. Proc Natl Acad Sci U S A 106:19197–19202.

    Not in our library10.1073/pnas.0906593106

  28. 28.

    Huang XF, Tan YY, Huang X, Wang Q (2007 ) Effect of chronic treatment with clozapine and haloperidol on 5-HT(2A and 2C) receptor mRNA expression in the rat brain. Neurosci Res 59:314–321.

    Not in our library10.1016/j.neures.2007.08.001

  29. 29.

    Jann MW, Grimsley SR, Gray EC, Chang WH (1993 ) Pharmacokinetics and pharmacodynamics of clozapine. Clin Pharmacokinet 24:161–176.

    Not in our library10.2165/00003088-199324020-00005

  30. 30.

    Jann MW, Lam YW, Chang WH (1994 ) Rapid formation of clozapine in guinea-pigs and man following clozapine-N-oxide administration. Arch Int Pharmacodyn Ther 328:243–250.

    Not in our library

  31. 31.
  32. 32.

    Keith VA, Mansbach RS, Geyer MA (1991 ) Failure of haloperidol to block the effects of phencyclidine and dizocilpine on prepulse inhibition of startle. Biol Psychiatry 30:557–566.

    Not in our library10.1016/0006-3223(91)90025-h

  33. 33.

    Lin G, McKay G, Hubbard JW, Midha KK (1994 ) Decomposition of clozapine N-oxide in the qualitative and quantitative analysis of clozapine and its metabolites. J Pharm Sci 83:1412–1417.

    Not in our library10.1002/jps.2600831010

  34. 34.

    Lin G, McKay G, Midha KK (1996 ) Characterization of metabolites of clozapine N-oxide in the rat by micro-column high performance liquid chromatography/mass spectrometry with electrospray interface. J Pharm Biomed Anal 14:1561–1577.

    Not in our library10.1016/0731-7085(96)01738-4

  35. 35.

    Ma S, Allocca G, Ong-Palsson EK, Singleton CE, Hawkes D, McDougall SJ, Williams SJ, Bathgate RA, Gundlach AL (2016 ) Nucleus incertus promotes cortical desynchronization and behavioral arousal. Brain Struct Funct. Advance online publication. Retrieved October 13, 2016. doi:10.1007/s00429-016-1230-0.

    Not in our library10.1007/s00429-016-1230-0

  36. 36.

    Marchant NJ, Whitaker LR, Bossert JM, Harvey BK, Hope BT, Kaganoversusky K, Adhikary S, Prisinzano TE, Vardy E, Roth BL, Shaham Y (2016 ) Behavioral and physiological effects of a novel kappa-opioid receptor-based DREADD in rats. Neuropsychopharmacology 41:402–409.

    Not in our library10.1038/npp.2015.149

  37. 37.

    Michaelides M, Anderson SA, Ananth M, Smirnov D, Thanos PK, Neumaier JF, Wang GJ, Volkow ND, Hurd YL (2013 ) Whole-brain circuit dissection in free-moving animals reveals cell-specific mesocorticolimbic networks. J Clin Invest 123:5342–5350.

    Not in our library10.1172/jci72117

  38. 38.

    Mizoguchi H, Katahira K, Inutsuka A, Fukumoto K, Nakamura A, Wang T, Nagai T, Sato J, Sawada M, Ohira H, Yamanaka A, Yamada K (2015 ) Insular neural system controls decision-making in healthy and methamphetamine-treated rats. Proc Natl Acad Sci U S A 112:E3930–E3939.

    Not in our library10.1073/pnas.1418014112

  39. 39.

    Mosier KE, Song J, McKay G, Hubbard JW, Fang J (2003 ) Determination of clozapine, and its metabolites, N-desmethylclozapine and clozapine N-oxide in dog plasma using high-performance liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 783:377–382.

    Not in our library10.1016/s1570-0232(02)00655-4

  40. 40.

    Natesan S, Reckless GE, Barlow KB, Nobrega JN, Kapur S (2007 ) Evaluation of N-desmethylclozapine as a potential antipsychotic–preclinical studies. Neuropsychopharmacology 32:1540–1549.

    Not in our library10.1038/sj.npp.1301279

All 63 references

Cited by papers we hold 7

Reads

Read by people on this page

None yet.

Checked or read by AI through naulon

None yet.

A person counts once a day per paper. We keep no cookie and no address: a reader is a hash that changes every day. Any month under five reads shows no number.

Are you an author?

Is this your paper?

Claim it to add your note and be paid when agents cite it. Free.