Fig. 7. (A) Effects of glutamate (Glu) on the membrane potential of valve muscle cells in the anterior median artery (AMA). All data were obtained from the same muscle cell. Bars on each trace indicate the period of Glu application. Concentrations of Glu are indicated under the bars. Numerals at the beginning of traces represent membrane potential (mV) in this and following figures. (B) The dose—response relationship between Glu concentrations and depolarization of valve muscle cells of AMA (filled circle). Membrane potentials were obtained from four animals. Resting membrane potentials (r.m.p.; open circle) were measured before doses. Values represent mean ± S.D. (N=4-6). (C) Effects of glutamatergic agonists kainate and quisqualate on the membrane potential of valve muscle cells in AMA. Bars indicate the periods of agonist perfusion.