title: Modulation of endocannabinoid-mediated long-lasting disinhibition of striatal output by cholinergic interneurons.
abstract: The frequency and duration of glutamatergic inputs to the striatum are strong determinants of the net effect of retrograde endocannabinoid (eCB) signaling, and key factors in determining if long-term depression (LTD) has a net disinhibitory or inhibitory action in striatum. Low to moderate frequency stimulation in the dorsolateral striatum elevates eCB levels to an extent that primarily depresses transmitter release at inhibitory synapses, leading to a long-lasting disinhibition (DLL) of synaptic output. The aim of this study was to further characterize the basic features of endocannabinoid-mediated DLL of striatal output induced by moderate frequency stimulation (5 Hz, 60 s). DLL was inhibited in slices treated with the group 1 metabotropic glutamate receptor (mGluR) antagonists MPEP (40 μM) and CPCCOEt (40 μM), the dopamine D2 receptor antagonist sulpiride (5 μM), the L-type calcium channel blocker nifedipine (20 μM), the nicotinic receptor antagonist mecamylamine (10 μM), the muscarinic agonist oxotremorine sesquifumarate (10 μM), and strychnine (0.1 μM). Strychnine did not block DLL induced by WIN55,212-2 (250 nM), showing that glycine receptor-mediated modulation of eCB signaling occurs upstream from CB(1)R activation. Scopolamine (10 μM) restored DLL in strychnine-treated slices, suggesting that inhibition of glycine receptors on cholinergic interneurons could modulate eCB signaling by enhancing muscarinic receptor activation and reducing the opening of L-type calcium channels in response to depolarization. These data suggests that similar activation points are required for stimulation-induced DLL as for LTD at excitatory striatal synapses, and that cholinergic interneurons are key modulators of stimulation-induced eCB signaling in the striatum.
authors.affiliation: Addiction Biology Unit, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Gothenburg, Box 410, 405 30 Gothenburg, Sweden. louise.adermark@neuro.gu.se
authors.forename: Louise
authors.initials: L
authors.lastname: Adermark
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001552:Benzazepines / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D001703:Biophysics; D063385:Cannabinoid Receptor Modulators / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018678:Cholinergic Agents / Q000494:pharmacology; D002867:Chromones / Q000494:pharmacology; D003342:Corpus Striatum / Q000166:cytology*; D018492:Dopamine Antagonists / Q000494:pharmacology; D004558:Electric Stimulation; D063388:Endocannabinoids; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D007395:Interneurons / Q000187:drug effects / Q000378:metabolism*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology; D008959:Models, Neurological; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D010880:Piperidines / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013469:Sulpiride / Q000494:pharmacology; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: C117789:7-(hydroxyimino)cyclopropan(b)chromen-1a-carbxoylic acid ethyl ester; D001552:Benzazepines; D063385:Cannabinoid Receptor Modulators; D018678:Cholinergic Agents; D002867:Chromones; D018492:Dopamine Antagonists; D063388:Endocannabinoids; D018691:Excitatory Amino Acid Antagonists; D058787:GABA-A Receptor Antagonists; D010880:Piperidines; D011720:Pyrazoles; D011725:Pyridines; C534628:SCH 23390; C103505:AM 251; C056639:2-amino-5-phosphopentanoic acid; D013469:Sulpiride; C121465:6-methyl-2-(phenylethynyl)pyridine; D014633:Valine; D001640:Bicuculline