Mice overexpressing CB2r (CB2xP) were exposed to open field (OF), light–dark box (LDB) and elevated plus maze (EPM) tests. Corticotropin-releasing factor (CRF) and pro-opiomelanocortin (POMC) mRNA were measured in paraventricular (PVN) and arcuate (ARC) nuclei of the hypothalamus after 30 minutes of restraint stress (RS). Anxiolytic effects of alprazolam (45 or 70 µg/kg, ip) were evaluated. GABAAα2 and GABAAγ2 mRNA were measured in the hippocampus (HIPP) and amygdala (AMY) of CB2xP and wild type (WT) mice. No differences were observed in the total distance travelled by CB2xP and WT mice in OF. Central and peripheral distances travelled significantly increased and decreased in CB2xP mice. Overexpression of CB2r reduced anxiety-like behaviours in LDB and EPM. In WT mice, RS increased CRF (82%) and POMC (42%) mRNA in the PVN and ARC nuclei, respectively. In CB2xP mice, RS also increased POMC (22%) mRNA in the ARC nucleus, but had no effect on CRF mRNA in the PVN nucleus. Administration of alprazolam was without effect in CB2xP mice. An increase of GABAAα2 and GABAAγ2 mRNA in the hippocampus and amygdala of CB2xP mice was observed. Our findings revealed that increased expression of CB2r significantly reduced anxiogenic-related behaviours, modified the response to stress and impaired the action of anxiolytic drugs.
AltemusMPigottTKalogerasKTDemitrackMDubbertBMurphyDL. (1992) Abnormalities in the regulation of vasopressin and corticotropin releasing factor secretion in obsessive-compulsive disorder. Arch Gen Psychiatry49: 9–20.
2.
ArboreliusLOwensMJPlotskyPMNemeroffCB. (1999) The role of corticotropin-releasing factor in depression and anxiety disorders. J Endocrinol160: 1–12.
3.
AsoEOzaitaAValdizánEMLedentCPazosAMaldonadoR. (2008) BDNF impairment in the hippocampus is related to enhanced despair behavior in CB1 knockout mice. J Neurochem105: 565–572.
4.
BankiCMKarmacsiLBissetteGNemeroffCB. (1992) Cerebrospinal fluid neuropeptides in dementia. Biol Psychiatry32: 452–456.
5.
BenitoCNúñezETolónRMCarrierEJRábanoAHillardCJ. (2003) Cannabinoid CB2 receptors and fatty acid amide hydrolase are selectively overexpressed in neuritic plaque-associated glia in Alzheimer's disease brains. J Neurosci23: 11136–11141.
6.
BenitoCRomeroJPTolónRMClementeDDocagneFHillardCJ. (2007) Cannabinoid CB1 and CB2 receptors and fatty acid amide hydrolase are specific markers of plaque cell subtypes in human multiple sclerosis. J Neurosci27: 2396–2402.
7.
BremnerJDLicinioJDarnellAKrystalJHOwensMJSouthwickSM. (1997) Elevated CSF corticotropin-releasing factor concentrations in posttraumatic stress disorder. Am J Psychiatry154: 624–629.
8.
ChappellPLeckmanJGoodmanWBissetteGPaulsDAndersonG. (1996) Elevated cerebrospinal fluid corticotropin-releasing factor in Tourette's syndrome: Comparison to obsessive compulsive disorder and normal controls. Biol Psychiatry39: 776–783.
9.
ConnollyCNKrishekBJMcDonaldBJSmartTGMossSJ. (1996) Assembly and cell surface expression of heteromeric and homomeric γ-aminobutyric acid type A receptors. J Biol Chem271: 89–96.
10.
CorcheroJFuentesJAManzanaresJ. (1999) Chronic treatment with CP-55,940 regulates corticotropin releasing factor and proopiomelanocortin gene expression in the hypothalamus and pituitary gland of the rat. Life Sci64: 905–911.
11.
CotaDSteinerMAMarsicanoGCervinoCHermanJPGrüblerY. (2007) Requirement of cannabinoid receptor type 1 for the basal modulation of hypothalamic-pituitary-adrenal axis function. Endocrinology148: 1574–1581.
12.
CrawleyJGoodwinFK. (1980) Preliminary report of a simple animal behavior model for the anxiolytic effects of benzodiazepines. Pharmacol Biochem Behav13: 167–170.
13.
Da SettimoFTalianiSTrincavelliMLMontaliMMartiniC. (2007) GABA A/Bz receptor subtypes as targets for selective drugs. Curr Med Chem14: 2680–2701.
14.
DevaneWADysarzFAIIIJohnsonMRMelvinLSHowlettAC. (1988) Determination and characterization of a cannabinoid receptor in rat brain. Mol Pharmacol34: 605–613.
15.
DunnAJBerridgeCW. (1990) Physiological and behavioral responses to corticotropin-releasing factor administration: Is CRF a mediator of anxiety or stress responses?Brain Res Brain Res Rev15: 71–100.
FosseyMDLydiardRBBallengerJCLaraiaMTBissetteGNemeroffCB. (1996) Cerebrospinal fluid corticotropin-releasing factor concentrations in patients with anxiety disorders and normal comparison subjects. Biol Psychiatry39: 703–707.
18.
GaliègueSMarySMarchandJDussossoyDCarrièreDCarayonP. (1995) Expression of central and peripheral cannabinoid receptors in human immune tissues and leukocyte subpopulations. Eur J Biochem232: 54–61.
19.
García-Gutiérrez MS and Manzanares J. (2009) Resistant depressive-like behaviours in transgenic mice overexpressing cannabinoid CB2 receptors. 39th Annual Meeting of the Society for Neuroscience, Society for Neuroscience, Poster Session, 342.15/P14.
20.
García-Gutiérrez MS, Pérez-Ortiz JM, Gutiérrez-Adán A. and Manzanares J (2010) Depression-resistant endophenotype in mice overexpressing cannabinoid CB2 receptors. Br J Pharmacol 160 (7): 1773–1784.
21.
GongJ-POnaiviESIshiguroHLiuQ-RTagliaferroPABruscoA. (2006) Cannabinoid CB2 receptors: immunohistochemical localization in rat brain. Brain Res1071: 10–23.
22.
GorrieGHVallisYStephensonAWhitfieldJBrowningBSmartTG. (1997) Assembly of GABAA receptors composed of α1 and β2 subunits in both cultured neurons and fibroblasts. J Neurosci17: 6587–6596.
23.
GuzmánMSánchezCGalve-RoperhI. (2001) Control of the cell survival/death decision by cannabinoids. J Mol Med78: 613–625.
24.
HallerJBakosNSzirmayMLedentCFreundTF. (2002) The effects of genetic and pharmacological blockade of the CB1 cannabinoid receptor on anxiety. Eur J Neurosci16: 1395–1398.
25.
HallerJVargaBLedentCBarnaIFreundTF. (2004) Context-dependent effects of CB1 cannabinoid gene disruption on anxiety-like and social behaviour in mice. Eur J Neurosci19: 1906–1912.
26.
HeimCEhlertUHellhammerDH. (2000) The potential role of hypocortisolism in the pathophysiology of stress-related bodily disorders. Psychoneuroendocrinology25: 1–35.
27.
HeimCOwensMJPlotskyPMNemeroffCB. (1997) The role of early adverse life events in the etiology of depression and posttraumatic stress disorder. Focus on corticotropin-releasing factor. Ann N Y Acad Sci821: 194–207.
28.
HerkenhamMLynnABJohnsonMRMelvinLSde CostaBRRiceKC. (1991) Characterization and localization of cannabinoid receptors in rat brain: A quantitative in vitro autoradiographic study. J Neurosci11: 563–583.
29.
JolkkonenJLepolaUBissetteGNemeroffCRiekkinenP. (1993) CSF corticotropin-releasing factor is not affected in panic disorder. Biol Psychiatry33: 136–138.
30.
JoostenMValkPJJordàMAVankan-BerkhoudtYVerbakelSvan den BroekM. (2002) Leukemic predisposition of pSca-1/Cb2 transgenic mice. Exp hematol30: 142–149.
31.
KittlerJTWangJConnollyCNViciniSSmartTGMossSJ. (2000) Analysis of GABAA receptor assembly in mammalian cell lines and hippocampal neurons using γ2 subunit green fluorescent protein chimeras. Mol Cell Neurosci16: 440–452.
32.
KvetnanskyRMitroAMikulajLHocmanG. (1966) [Catecholamines in the adrenal medulla and morphological changes of the adrenal medulla in the course of adaptation to repeated immobilization stress]. Bratisl Lek Listy46: 35–41.
33.
ListerRG. (1987) The use of a plus-maze to measure anxiety in the mouse. Psychopharmacology92: 180–185.
34.
LivakKJSchmittgenTD. (2001) Analysis of relative gene expression data using real-time quantitative PCR and the 2(-ΔΔCT) Method. Methods25: 402–408.
35.
LöwKCrestaniFKeistRBenkeDBrünigIBensonJA. (2000) Molecular and neuronal substrate for the selective attenuation of anxiety. Science290: 131–134.
36.
MackieK. (2005) Cannabinoid receptors as therapeutic targets. Annu Rev Pharmacol Toxicol46: 101–122.
37.
ManzanaresJCorcheroJFuentesJA. (1999) Opioid and cannabinoid receptor-mediated regulation of the increase in adrenocorticotropin hormone and corticosterone plasma concentrations induced by central administration of Δ9-tetrahydrocannabinol in rats. Brain Res839: 173–179.
38.
MatsudaLALolaitSJBrownsteinMJYoungACBonnerTI. (1990) Structure of a cannabinoid receptor and functional expression of the cloned cDNA. Nature346: 561–564.
39.
MorganNHStanfordIMWoodhallGL. (2009) Functional CB2 type cannabinoid receptors at CNS synapses. Neuropharmacology57: 356–368.
40.
MunroSThomasKLAbu-ShaarM. (1993) Molecular characterization of a peripheral receptor for cannabinoids. Nature365: 61–65.
41.
OnaiviES. (2006) Neuropsychobiological evidence for the functional presence and expression of cannabinoid CB2 receptors in the brain. Neuropsychobiology54: 231–246.
42.
OnaiviESIshiguroHGongJPPatelSMeozziPAMyersL. (2008a) Brain neuronal CB2 cannabinoid receptors in drug abuse and depression: from mice to human subjects. PLoS ONE3: e1640–e1640.
43.
OnaiviESIshiguroHGongJ-PPatelSMeozziPAMyersL. (2008b) Functional expression of brain neuronal CB2 cannabinoid receptors are involved in the effects of drugs of abuse and in depression. Ann N Y Acad Sci1139: 434–449.
PatelSRoelkeCTRademacherDJCullinanWEHillardCJ. (2004) Endocannabinoid signaling negatively modulates stress-induced activation of the hypothalamic-pituitary-adrenal axis. Endocrinology145: 5431–5438.
46.
PaxinosGFranklinKBJ. (2001) The mouse brain in stereotaxic coordinates. New York: Academic Press. Harcourt Science and Technology Company.
47.
PritchettDBLüddensHSeeburgPH. (1989) Type I and type II GABAA-benzodiazepine receptors produced in transfected cells. Science245: 1389–1392.
48.
RaczINadalXAlferinkJBañosJERehneltJMartínM. (2008a) Interferon-γ is a critical modulator of CB2 cannabinoid receptor signaling during neuropathic pain. J Neurosci28: 12136–12145.
49.
RaczINadalXAlferinkJBañosJERehneltJMartínM. (2008b) Crucial role of CB2 cannabinoid receptor in the regulation of central immune responses during neuropathic pain. J Neurosci28: 12125–12135.
50.
Roy-ByrnePPUhdeTWPostRMGallucciWChrousosGPGoldPW. (1986) The corticotropin-releasing hormone stimulation test in patients with panic disorder. Am J Psychiatry143: 896–899.
SteinerMAMarsicanoGNestlerEJHolsboerFLutzBWotjakCT. (2008) Antidepressant-like behavioral effects of impaired cannabinoid receptor type 1 signaling coincide with exaggerated corticosterone secretion in mice. Psychoneuroendocrinology33: 54–67.
53.
SteinerMAWotjakCT. (2008) Role of the endocannabinoid system in regulation of the hypothalamic-pituitary-adrenocortical axis. Prog Brain Res170: 397–432.
54.
Stenzel-PooreMPHeinrichsSCRivestSKoobGFValeWW. (1994) Overproduction of corticotropin-releasing factor in transgenic mice: A genetic model of anxiogenic behavior. J Neurosci14: 2579–2584.
55.
TimplPSpanagelRSillaberIKresseAReulJMStallaGK. (1998) Impaired stress response and reduced anxiety in mice lacking a functional corticotropin-releasing hormone receptor 1. Nat Genet19: 162–166.
56.
TsouKBrownSSañudo-PeñaMCMackieKWalkerJM. (1998) Immunohistochemical distribution of cannabinoid CB1 receptors in the rat central nervous system. Neuroscience83: 393–411.
57.
UrigüenLPérez-RialSLedentCPalomoTManzanaresJ. (2004) Impaired action of anxiolytic drugs in mice deficient in cannabinoid CB1 receptors. Neuropharmacology46: 966–973.
58.
WhitingPJ. (2003) The GABAA receptor gene family: New opportunities for drug development. Curr Opin Drug Discov Devel6: 648–657.
59.
YehudaR. (1997) Sensitization of the hypothalamic–pituitary–adrenal axis in posttraumatic stress disorder. Ann N Y Acad Sci821: 57–75.
60.
YiangouYFacerPDurrenbergerPChessellIPNaylorABountraC. (2006) COX-2, CB2 and P2X7-immunoreactivities are increased in activated microglial cells/macrophages of multiple sclerosis and amyotrophic lateral sclerosis spinal cord. BMC neurology6: 12–12.
61.
YoungWSIIIMezeyESiegelRE. (1986) Vasopressin and oxytocin mRNAs in adrenalectomized and Brattleboro rats: analysis by quantitative in situ hybridization histochemistry. Brain Res387: 231–241.
