Fig. 6

Discrete electrical coupling among neonatal astrocytes. a Dual patch recording from a pair of neonatal astrocytes in CA1 stratum radiatum. The recorded cells (DIC, left) were selected based on SR101 staining (right). B1, B2. A pair of electrically coupled (top), and uncoupled astrocytes (bottom), respectively. The current steps, shown in inset, were alternately delivered to the stimulated cell (C _stim.) that induced transjunctional voltage (V _{transjunction}) only in the recipient cell (C _reci.) of the coupled pair (top). c The coupling occurred in either VRA-VRA, PA-PA homotypic or VRA-PA heterotypic pairs. Likewise, the uncoupled pairs were not associated with either VRA or PA phenotypes. d Nearly all the PAs were coupled compared to 40 % of uncoupled VRAs. e The cell-to-cell pair distance was not associated the occurrence of cell coupling. f The recording configuration for coupling coefficient (CC) measurement, the V _COM voltages, ranging from −220 to +60 mV, were delivered to the C _stim. in voltage clamp mode, whereas the V _{transjunction} was recorded in the C _reci. in current clamp mode. g The CC values varied insignificantly throughout the test V _COM voltages (n = 9, P > 0.05). h The variation of CC values was independent of cell-to-cell pair distances. i The CC varied substantially among all the recorded pairs (n = 13)