Figure 4. Astrocytes form an electrically uniform syncytium in somatosensory barrel cortex.

V_M recordings with [Na⁺]_P from an astrocyte inside the barrel (A), and an astrocyte in the septum (B). Astrocytes were identified by positive SR101 staining (insets in A and B). (C) [Na⁺]_P V_M recording from astrocyte inside the barrel and within the septum as indicated. (D) Astrocytes inside the barrel and in septum show comparable V_M,_I, but significantly different V_M,_SS. Dual patch recording from a pair of neighboring astrocytes inside the barrel (E), and another pair with one astrocyte inside the barrel and another in the adjacent septum (F). (G) The command voltages (V_com), ±100 mV/50 ms, were alternately delivered to Cell1 and Cell2 as indicated below the recording traces, and the induced transjunctional current in the adjacent astrocyte is also indicated. Note that the transjunctional current is bidirectional.