Transmitter- and hormone-activated Ca(2+) responses in adult microglia/brain macrophages in situ recorded after viral transduction of a recombinant Ca(2+) sensor

Tools

Item Type:	Article
Title:	Transmitter- and hormone-activated Ca(2+) responses in adult microglia/brain macrophages in situ recorded after viral transduction of a recombinant Ca(2+) sensor
Creators Name:	Seifert, S., Pannell, M., Uckert, W., Faerber, K. and Kettenmann, H.
Abstract:	In vitro studies show that microglia, the resident immune cells of the brain, express neurotransmitter and neuropeptide receptors which are linked to Ca(2+) signaling. Here we describe an approach to obtain Ca(2+) recordings from microglia in situ. We injected a retrovirus encoding a calcium sensor into the cortex of mice 2 days after stimulation of microglial proliferation by a stab wound injury. Microglial cells were identified with tomato lectin in acute slices prepared 3, 6, 21 and 42 days after the injury. The membrane current profile and the ameboid morphology indicated that microglial cells were activated at day 6 while at day 42 they resembled resting microglia. We recorded transient Ca(2+) responses to application of ATP, endothelin-1, substance P, histamine and serotonin. The fluorescence amplitude of ATP was increased only at day 6 compared to other time points, while responses to all other ligands did not vary. Only half of the microglial cells that responded to ATP also responded to endothelin-1, serotonin and histamine. Substance P, in contrast, showed a complete overlap with the ATP responding microglial population at day 6, at day 42 this population was reduced to 55%. Cultured cells were less responsive to these ligands. This study shows that in situ microglia consist of heterogeneous populations with respect to their sensitivity to neuropeptides and -transmitters.
Keywords:	Microglia, Calcium, ATP, Endothelin-1, Serotonin, Substance P, Histamine, Neuropeptides, Neurotransmitter, Stab Wound, Animals, Mice
Source:	Cell Calcium
ISSN:	0143-4160
Publisher:	Elsevier
Volume:	49
Number:	6
Page Range:	365-375
Date:	June 2011
Official Publication:	https://doi.org/10.1016/j.ceca.2011.03.005
PubMed:	View item in PubMed

Repository Staff Only: item control page