Effects of on quisqualate-stimulated phosphoinositide hydrolysis in slices of kitten striate cortex

Stimulation of phosphoinositide (PI) hydrolysis by excitatory amino acids (EAAs) was studied in coronal slices of kitten visual cortex. Coincubation with (NMDA) markedly reduced the stimulation by quisqualate, however, this inhibition developed with a latency of > 10 min and occurred even when the NMDA exposure preceded, but did not overlap with,incubation in quisqualate. This time-course of NMDA inhibition of EAA-stimulated P1 turnover places new constraints on its possible mechanism of inhibition.