Fig. 4.

a Functional expression of AMPA/kainate glutamate receptors in Nestin-GFP-expressing cells in the amygdala. I During recording of membrane currents from a Nestin-GFP-expressing cell, kainate (KA, 0.5 mM, 30 s) was applied as indicated. The membrane was clamped from a holding potential of -70 mV to a series of de- and hyperpolarizing potentials ranging between -130 mV to +90 mV with 20-mV increments. At this time resolution, the single voltage steps cannot be resolved. II Four series of voltage steps from the recording shown in I taken before (1) and at the peak (2) of the kainate response and revealing the developed outward rectifying current (3) and the long-term blockage of the resting K⁺ conductance (4), but shown with higher time resolution (these traces were used to construct a current voltage curve, as shown in III, left). III, left Current voltage curves of long-term blockage of the resting K⁺ conductance were obtained by subtracting current amplitudes at the corresponding membrane potentials before and about 12 min after the kainate application (4-1). The reversal potential was close to -80 mV. The current voltage curves of the outward rectifying current were obtained by subtracting current amplitudes at the corresponding membrane potentials at the peak of the outward rectifying current and about 12 min after the kainate application (3-4). The reversal potential was close to -70 mV. III, right Current voltage curves of kainate-triggered responses were obtained by current amplitudes at the corresponding membrane potentials at the peak response during the kainate application (2). The reversal potential was at 0 mV. b Another profile of the kainate-evoked response current in Nestin-GFP-expressing cells in the amygdala. I As in a, kainate (0.5 mM, 30 s) was applied while recording membrane currents from a GFP-expressing cell that displayed a different kainate-triggered response profile over time (10 out of 21). II Three series of voltage steps from the recording shown in I taken before (1) and at the peak (2) of the kainate response and during long-term blockage of the resting K⁺ conductance (3), but shown with higher time resolution (these traces were used to construct a current voltage curve as shown in III). III, left Current voltage curves of long-term blockage of the resting K⁺ conductance were obtained by subtracting current amplitudes at the corresponding membrane potentials before and about 12 min after the kainate application (3-1). The reversal potential was close to -80 mV. III, right Current voltage curves of kainate-triggered responses were obtained by current amplitudes at the corresponding membrane potentials at the peak response during the kainate application (2). The reversal potential was at 0 mV. c Nestin-GFP-expressing cells in the amygdala lacked glutamate transporter currents. I No current response to D-aspartate (D-Asp) application (0.5 mM, 30 s) to nestin-GFP-expressing cells (n=10 out of 10). II, left Two series of voltage steps from the recording shown in I taken before (1) and during the D-aspartate application (2). II, right Current voltage curve; no current was induced by the D-aspartate application