Figure 1. Time course of sodium nitroprusside (SNP)-stimulated cGMP production in cultured neurons and glia from fetal rat brain. Primary cultures were prepared from the cerebral hemispheres of 16-day gestational Sprague-Dawley rats and experiments were carried out on day 12–16 in cultures. Cyclic GMP production was measured in mixed cultures of neurons and glia or glia alone at various time points after the addition of 100 micro Meter SNP. IBMX (100 micro Meter) was included in all reactions. Data represent the mean plus/minus SEM for n = 2 experiments, each performed in triplicate.