Figure 7. Muscimol-induced current response from an astrocyte in the corpus callosum and a neuron at the border of cortex to corpus callosum.

A, an astrocyte with passive membrane current was identified by its strong EGFP fluorescence (top left) in a GFAP-EGFP transgenic animal. B, a cortical neuron close to the corpus callosum was also identified by large Na⁺ currents in NMRI mice. Images of cells filled with Alexa Fluor 594 (10 μg ml⁻¹) via patch pipette are shown (top left). Membrane currents (top middle and bottom left) were recorded as described in Fig. 1 in response to muscimol (100 μm; 30 s). Voltage steps before (1), during (2) and after (3) muscimol-induced response are shown at a higher time resolution (bottom middle). Current–voltage plots were obtained by subtracting current responses at various time points as indicated (right).