RT Journal Article SR Electronic T1 Synaptic transmission onto hippocampal glial cells with hGFAP promoter activity JF Journal of Cell Science JO J. Cell Sci. FD The Company of Biologists Ltd SP 3791 OP 3803 DO 10.1242/jcs.02515 VO 118 IS 16 A1 Jabs, Ronald A1 Pivneva, Tatjana A1 Hüttmann, Kerstin A1 Wyczynski, Alexandra A1 Nolte, Christiane A1 Kettenmann, Helmut A1 Steinhäuser, Christian YR 2005 UL http://jcs.biologists.org/content/118/16/3791.abstract AB Glial cells increasingly gain importance as part of the brain's communication network. Using transgenic mice expressing green fluorescent protein (EGFP) under the control of the human GFAP promoter, we tested for synaptic input to identified glial cells in the hippocampus. Electron microscopic inspection identified synapse-like structures with EGFP-positive postsynaptic compartments. Sub-threshold stimulation to Schaffer collaterals resulted in stimulus-correlated, postsynaptic responses in a subpopulation of EGFP-positive cells studied with the patch-clamp technique in acute slices. This cell population can be recognized by its distinct morphology and has been termed GluR cells in a preceding study. These cells are distinct from the classical astrocytes due to their antigen profile and functional properties, but also lack characteristic features of oligodendrocytes or neurons. GluR cells also received spontaneous synaptic input. Stimulus-correlated and spontaneous responses were quantitatively analysed by ascertaining amplitude distributions, failure rates, kinetics as well as pharmacological properties. The data demonstrate that GABAergic and glutamatergic neurons directly synapse onto GluR cells and suggest a low number of neuronal release sites. These data demonstrate that a distinct type of glial cells is integrated into the synaptic circuit of the hippocampus, extending the finding that synapse-based brain information processing is not a property exclusive to neurons.