Figure 1.
Identification of astrocytes after mechanical isolation and the effect of glutamate on an individual astroglial cell. A, Epifluorescence image of an isolated astrocyte. B, Representative currents recorded from the astrocyte shown in A in response to hyperpolarizing and depolarizing steps from −120 to +40 mV (step interval, 20 mV), from the holding potential of −80 mV. C, Current–voltage relationship from isolated cortical astrocytes. Amplitudes of currents were normalized to the value measured at 0 mV (Inorm); points are mean ± SD for 20 cells. D, Voltage dependence of the current evoked by glutamate in an isolated astrocyte. The left panel shows currents induced by rapid application of glutamate (10 μm, 2 s) recorded at the different holding potentials as indicated. The right panel shows an I–V curve constructed from 11 independent experiments. The amplitudes of currents were normalized to the value measured at −40 mV (Inorm).