Effects of various classic antidepressants on [3H]phosphatidylinositide synthesis. Tissue slices prepared from indicated brain regions and prelabeled with [3H]inositol were incubated with various concentrations of either imipramine (IMI), desipramine (DES), fluoxetine (FLU), paroxetine (PAR), or maprotiline (MAP). After 90 min, [3H]inositol phospholipids were extracted and assayed as a total pool of extractable phosphatidylinositides. Each bar is the mean ± SEM (N = 9). Each drug stimulated significant and concentration-dependent increases in [3H]inositol phospholipid synthesis (ANOVA, p < 0.001 for each drug). From the subsequent posthoc Dunnett tests, all agents induced statistically significant CDP-diacylglycerol responses at the 3 or 10 μM and higher concentrations.