Cholinergic agonists increase intracellular Ca2+ in cultured human microglia.
Microglia are resident phagocytic cells in the central nervous system (CNS), and can be activated in response to various stimuli including neurotransmitters. Using fura-2 imaging, we investigated the effects of carbachol (CCh), a cholinergic agonist, on [Ca2+]i in cultured human microglia. Treatment of microglia with CCh (100 microM) produced a transient increase in [Ca2+]i, which was atropine-sensitive and was associated with release from intracellular Ca2+ stores. Successive applications of CCh showed a change in the amplitude of the [Ca2+]i signal consistent with desensitization. These results show that human microglia express functional muscarinic receptors and respond to cholinergic agonists. The rapid change of [Ca2+]i in microglia may serve as a second messenger to trigger downstream cascades which contribute to signalling pathways in CNS pathology.
Zhang
L
L
Department of Medicine, Faculty of Medicine, The University of British Columbia, Vancouver, Canada.
McLarnon
J G
JG
Goghari
V
V
Lee
Y B
YB
Kim
S U
SU
Krieger
C
C
D001285:Atropine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002217:Carbachol / Q000008:administration & dosage / Q000494:pharmacology*; D002478:Cells, Cultured; D018679:Cholinergic Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005333:Fetus; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism*; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009994:Osmolar Concentration
D018679:Cholinergic Agonists; D004338:Drug Combinations; D018727:Muscarinic Antagonists; D001285:Atropine; D002217:Carbachol; D002118:Calcium