Fig. 7. The [Ca²⁺]_c increases by the activation of metabotropic glutamate receptors. (A) 100 µM glutamate-mediated [Ca²⁺]_c rises in the absence/presence of ionotropic glutamate receptor antagonists (30 µM CNQX + 50 µM AP-5, n=6). (B) 100 µM glutamate-mediated [Ca²⁺]_c rises with and without calcium in the bath solution (n=5). (C) 100 µM glutamate- and DHPG (mGluR agonist)-mediated [Ca²⁺]_c increases (n=10). (D) Summary of the above data. 100% (control) means the peak values of [Ca²⁺]_c increases to 100 µM glutamate. CNQX and AP-5, 31.5±3.5% of control, n=6; glutamate in Ca²⁺-free solution, 23.7 ± 3.5%, n=5; DHPG in Ca²⁺-free solution, 19.3±4.2%, n=5; DHPG (31.3±1.9%, n=10. All the solutions contain 1 µM glycine.