Tissue-nonspecific alkaline phosphatase promotes axonal growth of hippocampal neurons

Axonal growth is essential for establishing neuronal circuits during brain development and for regenerative processes in the adult brain. Unfortunately, the extracellular signals controlling axonal growth are poorly understood. Here we report that a reduction in extracellular ATP levels by tissue-nonspecific alkaline phosphatase (TNAP) is essential for the development of neuritic processes by cultured hippocampal neurons. Selective blockade of TNAP activity with levamisole or specific TNAP knockdown with short hairpin RNA interference inhibited the growth and branching of principal axons, whereas addition of alkaline phosphatase (ALP) promoted axonal growth. Neither activation nor inhibition of adenosine receptors affected the axonal growth, excluding the contribution of extracellular adenosine as a potential hydrolysis product of extracellular ATP to the TNAP-mediated effects. TNAP was colocalized at axonal growth cones with ionotropic ATP receptors (P2X7 receptor), whose activation inhibited axonal growth. Additional analyses suggested a close functional interrelation of TNAP and P2X7 receptors whereby TNAP prevents P2X7 receptor activation by hydrolyzing ATP in the immediate environment of the receptor. Furthermore inhibition of P2X7 receptor reduced TNAP expression, whereas addition of ALP enhanced P2X7 receptor expression. Our results demonstrate that TNAP, regulating both ligand availability and protein expression of P2X7 receptor, is essential for axonal development

Quadratic Maps in Two Variables on Arbitrary Fields

Let $\mathbb{F}$ be a field of characteristic different from $2$ and $3$, and let $V$ be a vector space of dimension $2$ over $\mathbb{F}$. The generic classification of homogeneous quadratic maps $f\colon V\to V$ under the action of the linear group of $V$, is given and efficient computational criteria to recognize equivalence are provided.Comment: 12 pages, no figure

Asistencia espiritual en las Flotas de Indias

Págs. 271-282. Imágene

HENRY, Michel: Philosophie et phénoménologie du corps.

Sin resume

Las revistas culturales en la España de la posguerra (1939-1951): una aproximación

Este trabajo analiza el trasfondo ideológico de la posguerra española a través de las revistas culturales, deteniéndose en algunas publicaciones de cierta entidad, que se han mantenido a lo largo del tiempo y siguen editándose actualmente (Revista de Estudios Políticos, Arbor, Ínsula y Cuadernos Hispanoamericanos). Entre las aportaciones de este estudio cabe destacar la elaboración de un elenco de publicaciones periódicas con sus características principales hasta 1951. En suma, con esta investigación se ha pretendido profundizar en el marco cultural y social de los primeros años del franquismo.The Scientific Journals in Spain during the Postwar Period (1939-1951): a First Approach. This work studies the ideological background prevalent during the Spanish postwar through a review of the Spanish academicjournals, particularly of those with a more relevant significance and that have endure the pass of time, being now still printed, such as Revista de Estudios Políticos, Arbor, Ínsula y Cuadernos Hispanoamericanos. A special contribution of this work is the preparation of a catalogue of academic journals until 1951, describing in it their main features. The intention of the author is to study the academic and social context of Francos Regime during its early years

MILLÁN PUELLES, Antonio: La estructura de la subjetividad.

Sin resume

Avatares de las flotas de las Indias por las costas onubenses

Tomo I ; págs. 263-27