Fig. 8. Two phases of the [Ca²⁺]_c rise by activation of the metabotropic glutamate receptors. (A) Application of 10 µM DHPG (a) elicited characteristic [Ca²⁺]_c rises: the initial transient Ca²⁺ rise and long-sustained [Ca²⁺]_c elevation (n=7). Disappearance of the later persistent [Ca²⁺]_c elevation (b) under the Ca²⁺-free solution (n=7). (B) Effects of glutamate receptor antagonists on the late phase of glutamate-induced [Ca²⁺]_c increases. All the solutions contain 1 µM glycine. Note the glutamate concentration.