Fig. 5. Regional distribution and time course of cell-cell coupling. (A) Schematic representation of endogenous and incorporated ESGP-derived astrocytes used for analysis of network integration. (B-D) Examples of host-cell clusters coupled to individual GFP+ donor cells as seen by confocal analysis (each shown as overlay of 32 individual scans). After engraftment for 22-25 days, donor-derived astrocytes integrated equally well in glial networks of different anatomical regions of the recipient slice [molecular layer of the DG in B, EC/subiculum in C (as in Fig. 4B), TC region in D]. Both LY and GFP signals are recorded in the FITC channel. (E) Cell coupling of endogenous and engrafted ESGPs in three hippocampal subregions at different times in culture. Endogenous astrocytes reveal an increasing complexity of gap junction coupling during the culture period. After transplantation for 2-3 weeks, coupling ratios between donor and host cells in DG and EC equal those observed between endogenous astrocytes (engrafted slices were analyzed 12-25 days after donor cell deposition described in A). DG, dentate gyrus; dic, days in culture; dTx, days after deposition; EC, entorhinal cortex; TC, temporal cortex. Scale bars: 50 µm.