Table 1.

Effect of valproate on glutamate release and [³H]Ins(1,4,5)P₃ levels

	Glutamate	[3H]Ins(1,4,5)P3
Control	139  ± 5 nM	1,340  ± 62 dpm
Valproate (2 mM)	183  ± 11 nM	1,640  ± 28 dpm
Increase	31.4%	22%
P value for increase	0.008	0.003

Mouse cerebral cortex slices were prepared, prelabeled, and incubated as described in Experimental Procedures and in Fig. 1 with these modifications. myo-[³H]inositol was 0.1 mCi/ml during prelabeling. After aliquots of medium were taken for enzymatic determination of glutamate, the reaction was stopped with 3% perchloric acid, and the acid soluble extract was treated as described in Experimental Procedures.