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Abstract

The goldfish retina has been used extensively for the study of nerve regeneration. A role for phosphatidylinositol 3-kinase (PI3K) in neurite outgrowth from goldfish retinal explants has been examined by means of wortmannin (WT), a selective inhibitor of the enzyme. The presence of PI3K in retinal extracts was determined by means of immunoprecipitation as well as by an in vitro assay system for catalytic activity. The relative amount of the p85 subunit of PI3K detected by western blot in the retina following optic nerve crush was unchanged. WT inhibited goldfish brain PI3K activity at concentrations as low as 10(-9) M, approximating that reported for inhibition of mammalian PI3K's. Daily addition of 10(-8) M WT to retinal explants, activated by prior crush of the optic nerve, significantly inhibited neurite outgrowth during a 7 day in vitro culture period, while a single addition of WT to freshly explanted retina had no effect on neurite outgrowth. These results suggest that a PI3K-mediated process may be critical for nerve regrowth.

La luz en la Arquitectura. Su influencia sobre la salud de las personas. Estudio sobre la variabilidad del alumbrado artificial en oficinas

“…Ahora se sabe que nuestro periodo de sueño no se compone de un único y prolongado estadio, sino de 4 diferentes estadios (además del denominado REM), cuya aparición durante la noche no es un proceso aleatorio, sino un proceso organizado y definido. Bajo los diferentes estadios, nuestro cerebro registra ondas cerebrales de diversa actividad eléctrica [12].…”