Effects of N- 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 N- methyl- d -aspartate (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.