Enhanced acetylcholine release in the hippocampus of cannabinoid CB(1) receptor-deficient mice.
We examined whether acetylcholine release in the hippocampus and striatum and noradrenaline release in the hippocampus is altered in CB(1) receptor-deficient mice. The electrically evoked tritium overflow from hippocampal slices preincubated with [(3)H]-choline was increased by about 100% in CB(1)(-/-) compared to CB(1)(+/+) mice whereas the electrically evoked tritium overflow from striatal slices preincubated with [(3)H]-choline and from hippocampal slices preincubated with [(3)H]-noradrenaline did not differ. The cannabinoid receptor agonist, WIN 55,212-2, inhibited, and the CB(1) receptor antagonist, SR 141716, facilitated, the evoked tritium overflow from hippocampal slices (preincubated with [(3)H]-choline) from CB(1)(+/+) as opposed to CB(1)(-/-) mice. Both drugs did not affect the evoked tritium overflow from striatal slices (preincubated with [(3)H]-choline) and from hippocampal slices (preincubated with [(3)H]-noradrenaline) from CB(1)(+/+) and CB(1)(-/-) mice. The selective increase in acetylcholine release in CB(1)(-/-) mice may indicate that the presynaptic CB(1) receptors on the cholinergic neurones of the mouse hippocampus are tonically activated and/or constitutively active in vivo.
Kathmann
M
M
Institut für Pharmakologie und Toxikologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Reuterstr. 2b, 53113 Bonn, Germany.
Weber
B
B
Zimmer
A
A
Schlicker
E
E
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D048588:Benzoxazines; D002121:Calcium Channel Blockers / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D004558:Electric Stimulation; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009025:Morpholines / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug / Q000172:deficiency / Q000378:metabolism*; D000077285:Rimonabant; D014316:Tritium
D048588:Benzoxazines; D002121:Calcium Channel Blockers; D009025:Morpholines; D009281:Naphthalenes; D010880:Piperidines; D011720:Pyrazoles; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug; D014316:Tritium; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D000109:Acetylcholine; D000077285:Rimonabant; D009638:Norepinephrine