Fig. 1. Neuronal pathways involving PDEs.

Schematic of the regulation of cAMP synthesis by Adenylate Cyclases (AC) or s(soluble)AC and of cGMP synthesis by guanylate cyclases (GC) or s(soluble)GC. Specific degradation of cAMP and cGMP is catalyzed by various PDEs whose specificity is shown. Targets of cAMP and cGMP are shown, as well as well-known neuronal pathways involved in neurodevelopment. Red arrows indicate inhibition while green arrows indicate activation. PKA cAMP-dependent Protein Kinase, Ca²⁺CaM Ca²⁺/calmodulin-dependent protein kinase II, EPAC Exchange Protein directly Activated by cAMP, Rap Ras-related protein, ERK Extracellular signal-Regulated Kinase, Raf rapidly accelerated fibrosarcoma, DARP32 dopamine- and cAMP-regulated neuronal phosphoprotein, PP1 protein phosphatase-1, MEK MitogEn-activated protein kinase Kinase, PKG cGMP-dependent protein kinase, PrKG protein kinase, cGMP-dependent, GSK3 glycogen synthase kinase 3, iNOS inducible nitric oxide synthase; NO nitric oxide, CREB cAMP response element-binding protein, CNP C-type natriuretic peptide.