title: The endocannabinoid N-arachidonoyldopamine (NADA) exerts neuroprotective effects after excitotoxic neuronal damage via cannabinoid receptor 1 (CB(1)).
abstract: Endocannabinoids exert numerous effects in the CNS under physiological and pathological conditions. The aim of the present study was to examine whether the endocannabinoid N-arachidonoyldopamine (NADA) may protect neurons in excitotoxically lesioned organotypic hippocampal slice cultures (OHSC). OHSC were excitotoxically lesioned by application of N-methyl-d-aspartate (NMDA, 50 μM) for 4 h and subsequently treated with different NADA concentrations (0.1 pM-50 μM) alone or in combination with cannabinoid receptor antagonists. NADA protected dentate gyrus granule cells and caused a slight reduction in the number of microglial cells. The number of degenerated neurons significantly decreased between 100 pM and 10 μM NADA (p < 0.05). To identify the responsive receptor type of NADA mediated neuroprotection, we applied the cannabinoid (CB) receptor 1 (CB(1)) inverse agonist/antagonist AM251, CB(2) inverse agonist/antagonist AM630, abnormal-cannabidiol (abn-CBD)-sensitive receptor antagonist O-1918, transient receptor potential channel V1 (TRPV1) antagonist 6-iodonordihydrocapsaicin and A1 (TRPA1) antagonist HC-030031. Neuroprotective properties of low (1 nM) but not high (10 μM) NADA concentrations were solely blocked by AM251 and were absent in CB(1)(-/-) mice. AM630, O-1918, 6-iodonordihydrocapsaicin and HC-030031 showed no effects at all NADA concentrations applied. Our findings demonstrate that NADA protects dentate gyrus granule cells by acting via CB(1). NADA reduced the number of microglial cells at distinct concentrations. TRPV1 and TRPA1 were not involved in NADA mediated neuroprotection. Thus, our data implicate that NADA mediated activation of neuronal CB(1) may serve as a novel pharmacological target to mitigate symptoms of neuronal damage.
authors.affiliation: Institute of Anatomy, Leipzig University, Liebigstr. 13, 04103 Leipzig, Germany.
authors.forename: Urszula
authors.initials: U
authors.lastname: Grabiec
authors.forename: Marco
authors.initials: M
authors.lastname: Koch
authors.forename: Sonja
authors.initials: S
authors.lastname: Kallendrusch
authors.forename: Robert
authors.initials: R
authors.lastname: Kraft
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hill
authors.forename: Claudia
authors.initials: C
authors.lastname: Merkwitz
authors.forename: Chalid
authors.initials: C
authors.lastname: Ghadban
authors.forename: Beat
authors.initials: B
authors.lastname: Lutz
authors.forename: Alex
authors.initials: A
authors.lastname: Straiker
authors.forename: Faramarz
authors.initials: F
authors.lastname: Dehghani
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology*; D002478:Cells, Cultured; D004298:Dopamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D009410:Nerve Degeneration / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism*
chemical_list: D001095:Arachidonic Acids; D018696:Neuroprotective Agents; D010880:Piperidines; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; C474941:arachidonyl dopamine; C103505:AM 251; D004298:Dopamine