INTEQUI   20941
INSTITUTO DE INVESTIGACIONES EN TECNOLOGIA QUIMICA
Unidad Ejecutora - UE
artículos
Título:
"A new semisynthetic derivative of sauroine induces LTP in hippocampal slices and improves learning perfomance in the Morris Water Maze"
Autor/es:
VALLEJO, M.G.; LOYOLA, S.; CONTRERAS, D.; UGARTE, G.; CIFUENTE, D.A.; ORTEGA, M.G.; CABRERA, J.L; ZEISE, M. ; TONN, C.E.; CARREÑO, M. ; DELGADO, D.; MORALES, B.; AGNESE, M.
Revista:
JOURNAL OF NEUROCHEMISTRY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2014 vol. 129 p. 864 - 876
ISSN:
0022-3042
Resumen:
Abstract Two semisynthetic acetyl derivatives of the alkaloid sauroine from Huperzia saururus, monoacetyl sauroine, and diacetyl sauroine (DAS) were obtained and their chemical structures were analyzed by NMR. While monoacetyl sauroine is the typical product of acetylation, DAS is an unexpected derivative related to the keto-enol formation of sauroine. Recordings of field excitatory post-synaptic potentials from the CA1 region of rat hippocampal slices showed that only DAS acutely applied induced chemical long-term potentiation (LTP) in a dose-dependent manner with an EC50 of 1.15 _ 0.09 lM. This effectwasblockedby10 lMD(-)-2-amino-5-phosphonopentanoic acid (AP5), suggesting dependence on the NMDA receptor. DAS significantly increased NMDA receptor-dependent excitatory post-synaptic currents without affecting a-amino- 3-hydroxy-5-methylisoxazole-4-propionate receptor-dependent currents. Repetitive administration of DAS improved visuospatial learning in the Morris Water Maze. In slices from rats tested in the Morris Water Maze, LTP resulting from electrical synaptic stimulation was 2.5 times larger than in controls. Concentration of DAS measured in the brain after repetitive administration was 29.5 lM. We conclude that slices perfused with DAS display a robust NMDA receptor-dependent chemical LTP. During chronic treatment, DAS enhances learning abilities through a metaplastic mechanism as revealed by the augmentation of LTP in slices. DAS, therefore, may be a promising compound as a nootropic therapeutic drug. Keywords: learning and memory, long-term potentiation, lycopodium alkaloids, metaplasticity, sauroine acetylation, synaptic plasticity.