Liste des publications

Team publications

IF du Neurocentre

154 publications

* equal contribution
The indicated IF have been collected by the Web of Sciences in June 2019

10/2007 | PLoS Biol   IF 8.4
Genetic dissection of behavioural and autonomic effects of Delta(9)-tetrahydrocannabinol in mice
Monory K, Blaudzun H, Massa F, Kaiser N, Lemberger T, Schutz G, Wotjak C T, Lutz B, Marsicano G

Marijuana and its main psychotropic ingredient Delta(9)-tetrahydrocannabinol (THC) exert a plethora of psychoactive effects through the activation of the neuronal cannabinoid receptor type 1 (CB1), which is expressed by different neuronal subpopulations in the central nervous system. The exact neuroanatomical substrates underlying each effect of THC are, however, not known. We tested locomotor, hypothermic, analgesic, and cataleptic effects of THC in conditional knockout mouse lines, which lack the expression of CB1 in different neuronal subpopulations, including principal brain neurons, GABAergic neurons (those that release gamma aminobutyric acid), cortical glutamatergic neurons, and neurons expressing the dopamine receptor D1, respectively. Surprisingly, mice lacking CB1 in GABAergic neurons responded to THC similarly as wild-type littermates did, whereas deletion of the receptor in all principal neurons abolished or strongly reduced the behavioural and autonomic responses to the drug. Moreover, locomotor and hypothermic effects of THC depend on cortical glutamatergic neurons, whereas the deletion of CB1 from the majority of striatal neurons and a subpopulation of cortical glutamatergic neurons blocked the cataleptic effect of the drug. These data show that several important pharmacological actions of THC do not depend on functional expression of CB1 on GABAergic interneurons, but on other neuronal populations, and pave the way to a refined interpretation of the pharmacological effects of cannabinoids on neuronal functions.

09/2007 | Neurogastroenterol Motil   IF 3.8
Cannabinoid type 1 receptor modulates intestinal propulsion by an attenuation of intestinal motor responses within the myenteric part of the peristaltic reflex
Yuece B, Sibaev A, Broedl U C, Marsicano G, Goke B, Lutz B, Allescher H D, Storr M

Cannabinoid-1 (CB1) receptor activation affects gastrointestinal propulsion in vivo. It was our aim to further characterize the involved myenteric mechanisms in vivo and in vitro. In CB1(-/-) mice and wild-type littermates we performed in vivo transit experiments by charcoal feeding and in vitro electrophysiological recordings in mouse small intestinal smooth muscle. Ascending neuronal contraction (ANC) following electrical field stimulation was studied in rat ileum in a partitioned organ bath separating the aboral stimulation site from the oral recording site. The knockout animals displayed an accelerated upper gastrointestinal transit compared to control animals. The CB1 receptor antagonist AM251 stimulated the force of the ANC in a concentration dependent manner when added in the oral chamber. Anandamide significantly inhibited the ANC when added in the oral chamber. Neither AM251 nor anandamide had an influence on the contraction latency. No effects were observed when drugs were added in the aboral chamber, proving a CB1 mediated action on the neuromuscular junction. Resting membrane potentials and neuronal induced inhibitory junction potentials in CB1(-/-) mice were unchanged as compared to wild type. However, the electrophysiological slow waves were more sensitive to blockade of Ca(2+) channels in CB1(-/-) mice. Our data strongly suggest a physiological involvement of the CB-1 receptor in the regulation of small intestinal motility. Therefore, CB1 receptors are a promising target for the treatment of motility disorders.

17/08/2007 | J Biol Chem   IF 4.1
The CB1 cannabinoid receptor mediates excitotoxicity-induced neural progenitor proliferation and neurogenesis
Aguado T, Romero E, Monory K, Palazuelos J, Sendtner M, Marsicano G, Lutz B, Guzman M, Galve-Roperh I

Endocannabinoids are lipid signaling mediators that exert an important neuromodulatory role and confer neuroprotection in several types of brain injury. Excitotoxicity and stroke can induce neural progenitor (NP) proliferation and differentiation as an attempt of neuroregeneration after damage. Here we investigated the mechanism of hippocampal progenitor cell engagement upon excitotoxicity induced by kainic acid administration and the putative involvement of the CB1 cannabinoid receptor in this process. Adult NPs express kainate receptors that mediate proliferation and neurosphere generation in vitro via CB1 cannabinoid receptors. Similarly, in vivo studies showed that excitotoxicity-induced hippocampal NPs proliferation and neurogenesis are abrogated in CB1-deficient mice and in wild-type mice administered with the selective CB1 antagonist rimonabant (N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyrazol ecarboxamide; SR141716). Kainate stimulation increased basic fibroblast growth factor (bFGF) expression in cultured NPs in a CB1-dependent manner as this response was prevented by rimonabant and mimicked by endocannabinoids. Likewise, in vivo analyses showed that increased hippocampal expression of bFGF, as well as of brain-derived neurotrophic factor and epidermal growth factor, occurs upon excitotoxicity and that CB1 receptor ablation prevents this induction. Moreover, excitotoxicity increased the number of CB1+ bFGF+ cells, and this up-regulation preceded NP proliferation. In summary, our results show the involvement of the CB1 cannabinoid receptor in NP proliferation and neurogenesis induced by excitotoxic injury and support a role for bFGF signaling in this process.

07/2007 | Nat Neurosci   IF 21.1
Cannabinoids mediate analgesia largely via peripheral type 1 cannabinoid receptors in nociceptors
Agarwal N, Pacher P, Tegeder I, Amaya F, Constantin C E, Brenner G J, Rubino T, Michalski C W, Marsicano G, Monory K, Mackie K, Marian C, Batkai S, Parolaro D, Fischer M J, Reeh P, Kunos G, Kress M, Lutz B, Woolf C J, Kuner R

Although endocannabinoids constitute one of the first lines of defense against pain, the anatomical locus and the precise receptor mechanisms underlying cannabinergic modulation of pain are uncertain. Clinical exploitation of the system is severely hindered by the cognitive deficits, memory impairment, motor disturbances and psychotropic effects resulting from the central actions of cannabinoids. We deleted the type 1 cannabinoid receptor (CB1) specifically in nociceptive neurons localized in the peripheral nervous system of mice, preserving its expression in the CNS, and analyzed these genetically modified mice in preclinical models of inflammatory and neuropathic pain. The nociceptor-specific loss of CB1 substantially reduced the analgesia produced by local and systemic, but not intrathecal, delivery of cannabinoids. We conclude that the contribution of CB1-type receptors expressed on the peripheral terminals of nociceptors to cannabinoid-induced analgesia is paramount, which should enable the development of peripherally acting CB1 analgesic agonists without any central side effects.

27/06/2007 | J Neurosci   IF 6.1
Role of cannabinoid type 1 receptors in locomotor activity and striatal signaling in response to psychostimulants
Corbille A G, Valjent E, Marsicano G, Ledent C, Lutz B, Herve D, Girault J A

A single administration of cocaine or D-amphetamine produces acute hyperlocomotion and long-lasting increased sensitivity to subsequent injections. This locomotor sensitization reveals the powerful ability of psychostimulants to induce brain plasticity and may participate in the alterations that underlie addiction. We investigated the role of cannabinoid receptor type 1 (CB1-R) in the effects of a single injection of psychostimulants. The acute locomotor response to cocaine was normal in mice pretreated with the CB1-R inverse agonist N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyr azole-3-carboxamide (AM251), whereas no sensitization was observed in response to a second administration a week later. Locomotor responses to cocaine and D-amphetamine were decreased in CB1-R-deficient mice, and sensitization was impaired. To determine how CB1-R controls long-lasting effects of psychostimulants, we studied cocaine-activated signaling pathways. Cocaine-induced cAMP-dependent phosphorylation of glutamate receptor 1 was altered in the striatum of CB1-R mutant mice but not of AM251-treated mice. In contrast, cocaine-induced phosphorylation of extracellular signal-regulated kinase (ERK) was blocked in both CB1-R mutant and antagonist-pretreated mice. Conditional deletion of CB1-R in forebrain principal neurons or GABAergic neurons prevented cocaine-induced ERK activation in dorsal striatum and nucleus accumbens. Our results provide strong evidence for the role of the endocannabinoid system in regulating neuronal circuits critical for long-lasting effects of cocaine, presumably by acting on CB1-R located on terminals of striatal medium spiny neurons.

25/05/2007 | Neuroscience   IF 3.2
Identification of the cannabinoid receptor type 1 in serotonergic cells of raphe nuclei in mice
Haring M, Marsicano G, Lutz B, Monory K

The endocannabinoid system (ECS) possesses neuromodulatory functions by influencing the release of various neurotransmitters, including GABA, noradrenaline, dopamine, glutamate and acetylcholine. Even though there are studies indicating similar interactions between the ECS and the serotonergic system, there are no results showing clear evidence for type 1 cannabinoid receptor (CB1) location on serotonergic neurons. In this study, we show by in situ hybridization that a low but significant fraction of serotonergic neurons in the raphe nuclei of mice contains CB1 mRNA as illustrated by the coexpression with the serotonergic marker gene tryptophane hydroxylase 2, the rate limiting enzyme for the serotonin synthesis. Furthermore, by double immunohistochemistry and confocal microscopy, we were able to detect CB1 protein on serotonergic fibers and synapses expressing the serotonin uptake transporter in the hippocampus and the amygdala. Our findings indicate that the CB1-mediated regulation of serotonin release can depend in part on a direct cross-talk between the two systems at single cell level, which might lead to functional implications in the modulation of emotional states.

25/05/2007 | Science   IF 41
Hardwiring the brain: endocannabinoids shape neuronal connectivity
Berghuis P, Rajnicek A M, Morozov Y M, Ross R A, Mulder J, Urban G M, Monory K, Marsicano G, Matteoli M, Canty A, Irving A J, Katona I, Yanagawa Y, Rakic P, Lutz B, Mackie K, Harkany T

The roles of endocannabinoid signaling during central nervous system development are unknown. We report that CB(1) cannabinoid receptors (CB(1)Rs) are enriched in the axonal growth cones of gamma-aminobutyric acid-containing (GABAergic) interneurons in the rodent cortex during late gestation. Endocannabinoids trigger CB(1)R internalization and elimination from filopodia and induce chemorepulsion and collapse of axonal growth cones of these GABAergic interneurons by activating RhoA. Similarly, endocannabinoids diminish the galvanotropism of Xenopus laevis spinal neurons. These findings, together with the impaired target selection of cortical GABAergic interneurons lacking CB(1)Rs, identify endocannabinoids as axon guidance cues and demonstrate that endocannabinoid signaling regulates synaptogenesis and target selection in vivo.

04/2007 | Endocrinology   IF 3.8
Requirement of cannabinoid receptor type 1 for the basal modulation of hypothalamic-pituitary-adrenal axis function
Cota D, Steiner M A, Marsicano G, Cervino C, Herman J P, Grubler Y, Stalla J, Pasquali R, Lutz B, Stalla G K, Pagotto U

The endocannabinoid system affects the neuroendocrine regulation of hormone secretion, including the activity of the hypothalamus-pituitary-adrenal (HPA) axis. However, the mechanisms by which endocannabinoids regulate HPA axis function have remained unclear. Here we demonstrate that mice lacking cannabinoid receptor type 1 (CB1-/-) display a significant dysregulation of the HPA axis. Although circadian HPA axis responsiveness is preserved, CB1-/- mice are characterized by an enhanced circadian drive on the HPA axis, resulting in elevated plasma corticosterone concentrations at the onset of the dark as compared with wild-type (CB1+/+) littermates. Moreover, CB1-/--derived pituitary cells respond with a significantly higher ACTH secretion to CRH and forskolin challenges as compared with pituitary cells derived from CB1+/+ mice. Both CBL-/- and CB1+/+ mice properly respond to a high-dose dexamethasone test, but response to low-dose dexamethasone is influenced by genotype. In addition, CB1-/- mice show increased CRH mRNA levels in the paraventricular nucleus of the hypothalamus but not in other extrahypothalamic areas, such as the amygdala and piriform cortex, in which CB1 and CRH mRNA have been colocalized. Finally, CB1-/- mice have selective glucocorticoid receptor mRNA down-regulation in the CA1 region of the hippocampus but not in the dentate gyrus or paraventricular nucleus. Conversely, mineralocorticoid receptor mRNA expression levels were found unchanged in these brain areas. In conclusion, our findings indicate that CB1 deficiency enhances the circadian HPA axis activity peak and leads to central impairment of glucocorticoid feedback, thus further outlining the essential role of the endocannabinoid system in the modulation of neuroendocrine functions.

04/2007 | Nat Med   IF 30.6
Direct suppression of CNS autoimmune inflammation via the cannabinoid receptor CB1 on neurons and CB2 on autoreactive T cells
Maresz K, Pryce G, Ponomarev E D, Marsicano G, Croxford J L, Shriver L P, Ledent C, Cheng X, Carrier E J, Mann M K, Giovannoni G, Pertwee R G, Yamamura T, Buckley N E, Hillard C J, Lutz B, Baker D, Dittel B N

The cannabinoid system is immunomodulatory and has been targeted as a treatment for the central nervous system (CNS) autoimmune disease multiple sclerosis. Using an animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), we investigated the role of the CB(1) and CB(2) cannabinoid receptors in regulating CNS autoimmunity. We found that CB(1) receptor expression by neurons, but not T cells, was required for cannabinoid-mediated EAE suppression. In contrast, CB(2) receptor expression by encephalitogenic T cells was critical for controlling inflammation associated with EAE. CB(2)-deficient T cells in the CNS during EAE exhibited reduced levels of apoptosis, a higher rate of proliferation and increased production of inflammatory cytokines, resulting in severe clinical disease. Together, our results demonstrate that the cannabinoid system within the CNS plays a critical role in regulating autoimmune inflammation, with the CNS directly suppressing T-cell effector function via the CB(2) receptor.

10/2006 | Neurobiol Dis   IF 5.2
Protective activation of the endocannabinoid system during ischemia in dopamine neurons
Melis M, Pillolla G, Bisogno T, Minassi A, Petrosino S, Perra S, Muntoni A L, Lutz B, Gessa G L, Marsicano G, Di Marzo V, Pistis M

Endocannabinoids act as neuroprotective molecules promptly released in response to pathological stimuli. Hence, they may represent one component of protection and/or repair mechanisms mobilized by dopamine (DA) neurons under ischemia. Here, we show that the endocannabinoid 2-arachidonoyl-glycerol (2-AG) plays a key role in protecting DA neurons from ischemia-induced altered spontaneous activity both in vitro and in vivo. Accordingly, neuroprotection can be elicited through moderate cannabinoid receptor type-1 (CB1) activation. Conversely, blockade of endocannabinoid actions through CB1 receptor antagonism worsens the outcome of transient ischemia on DA neuronal activity. These findings indicate that 2-AG mediates neuroprotective actions by delaying damage and/or restoring function of DA cells through activation of presynaptic CB1 receptors. Lastly, they point to CB1 receptors as valuable targets in protection of DA neurons against ischemic injury and emphasize the need for a better understanding of endocannabinoid actions in the fine control of DA transmission.