Figure 3.

NST astrocytes are directly activated by calcium influx through AMPA receptors. A, Under time control conditions, similar increases in astrocytic [Ca²⁺]_i are seen in response to repetitive bath application of the AMPAR agonist AMPA (n = 53 cells). B, Although treatment with TTX caused a reduction in the response to the second application of AMPA, the resulting response remained essentially intact (n = 31 cells). However, the response to the second application of AMPA was blocked by intervening treatment with either 30 μm NBQX, an AMPAR antagonist (C; n = 28 cells), or Ca²⁺-free Krebs' media (D; n = 60 cells). Raw traces on the right of each panel represent the average response of five cells before and after experimental manipulation. *p < 0.05, paired t test.