The cellular prion protein (PrP C ) is a membrane-bound glycoprotein especially abundant in the central nervous system (CNS). The scrapie prion protein (PrP Sc, also termed prions) is responsible of transmissible spongiform encephalopathies (TSE), a group of neurodegenerative diseases which affect humans and other mammal species, although the presence of PrP C is needed for the establishment and further evolution of prions.The present work compares the expression and localization of PrP C between healthy human brains and those suffering from Alzheimer disease (AD).In both situations we have observed a rostrocaudal decrease in the amount of PrP C within the CNS, both by immunoblotting and immunohistochemistry techniques. PrP C is higher expressed in our control brains than in AD cases. There was a neuronal loss and astogliosis in our AD cases. There was a tendency of a lesser expression of PrP C in AD cases than in healthy ones. And in AD cases, the intensity of the expression of the unglycosylated band is higher than the di-and monoglycosylated bands.With regards to amyloid plaques, those present in AD cases were positively labeled for PrP C , a result which is further supported by the presence of PrP C in the amyloid plaques of a transgenic line of mice mimicking AD.The work was done according to Helsinki Declaration of 1975, and approved by the Ethics Committee

El sueño es un estado biológico activo, periódico, en el que se distinguen las etapas NREM y REM, que se alternan sucesivamente durante la noche. Intervienen los relojes biológicos en la modulación del sistema, así como neurotransmisores específicos. Se trata de una red neuronal compleja, en la que intervienen diversas zonas del sistema nervioso central. Los procesos oníricos están controlados además de forma neural. Se resume la historia de las investigaciones sobre el tema, desde el siglo XIX hasta nuestra época. Hay que destacar los recientes descubrimientos de Lugaresi y su equipo, que, al describir el insomnio familiar grave, dieron importancia al núcleo dorsomedial del tálamo en la instauración de la fase de sueño profundo. Al grupo de Reinoso se debe el hallazgo de que el "director de orquesta" en la instauración del sueño REM es la zona ventral paramediana del núcleo reticular pontino oral Palabras clave. Sueño. Vigilia. Centros neurales. REM. NREM.

Our findings support the hypothesis of a retrograde transport of PrPsc in the SNC. PrPc could be related to the pathophysiology of EA.

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The cellular prion protein (PrPC) expression was analyzed by western-blot