Figure 1.

Dominant-negative SNARE transgenes are expressed in hippocampal and cortical astrocytes. A, Schematic of the generation of the bitransgenic mice expressing dnSNARE in glia. Two different lines of transgenic mice have been previously described by Pascual et al. (2005). One is a line of mice in which the human GFAP promoter drives the expression of tTA. The second, tetO.dnSNARE contains a tet operator (tetO)-regulated dnSNARE domain and EGFP reporter gene. By crossing these two lines, the dnSNARE domain is expressed only in astrocytes. All mice were maintained on +Dox until the beginning of the experiments. Three to 4 weeks before experiments, mice were put off doxycycline food (−Dox) to induce dnSNARE expression. B, Confocal images showing expression of the reporter transgene EGFP (green) throughout the different hippocampal subfields [dentate gyrus (DG), CA3, and CA1] and cortex after 4–5 weeks off doxycycline food (−Dox). Propidium iodide (red) was used as a neuronal marker. Magnification ×20.