Phosphodiesterase type 5 inhibition improves early memory consolidation of object information

The nitric oxide (NO)-cyclic GMP (cGMP) signaling pathway is assumed to play an important role in processes underlying learning and memory. We used phosphodiesterase type 5 (PDE5) inhibitors to study the role of cGMP in object- and spatial memory. Our results and those reported in other studies indicate that elevated hippocampal cGMP levels are required to improve the memory performance of rodents in object recognition and passive avoidance learning, but not in spatial learning. The timing of treatment modulates the effects on memory and strongly supports a role for cGMP in early stages of memory formation. Alternative explanations for the improved memory performance of PDE5 inhibitors are also discussed. Immunocytochemical studies showed that in vitro slice incubations with PDE5 inhibitors increase NO-stimulated cGMP levels mainly in hippocampal varicose fibers. Reviewing the available data on the localization of the different components of the NO-cGMP signaling pathway, indicates a complex interaction between NO and cGMP, which may be independent of each other. It is discussed that further studies are needed, immunocytochemical and behavioral, to better understand the cGMP-mediated molecular mechanisms underlying memory formation

Phosphodiesterase type 5 inhibition improves early memory consolidation of object information

The nitric oxide (NO)-cyclic GMP (cGMP) signaling pathway is assumed to play an important role in processes underlying learning and memory. We used phosphodiesterase type 5 (PDE5) inhibitors to study the role of cGMP in object- and spatial memory. Our results and those reported in other studies indicate that elevated hippocampal cGMP levels are required to improve the memory performance of rodents in object recognition and passive avoidance learning, but not in spatial learning. The timing of treatment modulates the effects on memory and strongly supports a role for cGMP in early stages of memory formation. Alternative explanations for the improved memory performance of PDE5 inhibitors are also discussed. Immunocytochemical studies showed that in vitro slice incubations with PDE5 inhibitors increase NO-stimulated cGMP levels mainly in hippocampal varicose fibers. Reviewing the available data on the localization of the different components of the NO-cGMP signaling pathway, indicates a complex interaction between NO and cGMP, which may be independent of each other. It is discussed that further studies are needed, immunocytochemical and behavioral, to better understand the cGMP-mediated molecular mechanisms underlying memory formation

Germline mutations in the PTEN/MMAC1 gene in patients with Cowden disease

Contains fulltext : 25911___.PDF (publisher's version ) (Open Access

Inhibition of phosphodiesterase 2 increases nuronal cGMP, synaptic plasticity and memory performance

An essential element of the signalling cascade leading to synaptic plasticity is the intracellular second messenger molecule guanosine 3',5'-cyclic monophosphate (cGMP). Using the novel, potent, and selective inhibitor Bay 60-7550, we show that the enzyme 3',5'-cyclic nucleotide phosphodiesterase type 2 (PDE2) is responsible for the degradation of newly synthesized cGMP in cultured neurons and hippocampal slices. Inhibition of PDE2 enhanced long-term potentiation of synaptic transmission without altering basal synaptic transmission. Inhibition of PDE2 also improved the performance of rats in social and object recognition memory tasks, and reversed MK801-induced deficits in spontaneous alternation in mice in a T-maze. Our data provide strong evidence that inhibition of PDE2 can improve memory functions by enhancing neuronal plasticity

Inhibition of phosphodiesterase 2 increases neuronal cGMP, synaptic plasticity and memory performance

An essential element of the signalling cascade leading to synaptic plasticity is the intracellular second messenger molecule guanosine 3¿,5¿-cyclic monophosphate (cGMP). Using the novel, potent, and selective inhibitor Bay 60-7550, we show that the enzyme 3¿,5¿-cyclic nucleotide phosphodiesterase type 2 (PDE2) is responsible for the degradation of newly synthesized cGMP in cultured neurons and hippocampal slices. Inhibition of PDE2 enhanced long-term potentiation of synaptic transmission without altering basal synaptic transmission. Inhibition of PDE2 also improved the performance of rats in social and object recognition memory tasks, and reversed MK801-induced deficits in spontaneous alternation in mice in a T-maze. Our data provide strong evidence that inhibition of PDE2 can improve memory functions by enhancing neuronal plasticit