The autophagic machinery is necessary for removal of cell corpses from the developing retinal neuroepithelium

12 páginas, 8 figuras -- PAGS nros. 1279-1290Autophagy is a homoeostatic process necessary for the clearance of damaged or superfluous proteins and organelles. The recycling of intracellular constituents also provides energy during periods of metabolic stress, thereby contributing to cell viability. In addition, disruption of autophagic machinery interferes with embryonic development in several species, although the underlying cellular processes affected remain unclear. Here, we investigate the role of autophagy during the early stages of chick retina development, when the retinal neuroepithelium proliferates and starts to generate the first neurons, the retinal ganglion cells. These two developmental processes are accompanied by programmed cell death. Upon treatment with the autophagic inhibitor 3-methyladenine, retinas accumulated numerous TdT-mediated dUTP nick-end labelling-positive cells that correlated with a lack of the ‘eat-me’ signal phosphatidylserine (PS). In consequence, neighbouring cells did not engulf apoptotic bodies and they persisted as individual cell corpses, a phenotype that was also observed after blockade of phagocytosis with phospho-L-Serine. Supplying the retinas with methylpyruvate, a cell-permeable substrate for ATP production, restored ATP levels and the presentation of PS at the cell surface. Hence, engulfment and lysosomal degradation of apoptotic bodies were also re-established. Together, these data point to a novel role for the autophagic machinery during the development of the central nervous systemThis research was supported by grants from the Spanish Ministerio de Educación y Ciencia (BFU2006-00508 to PB and SAF2007-66175 to EJdlR) and Comunidad de Madrid (CCG06-CSIC/SAL-0821 to PB). MAM is a FPU Fellow and PB is a Ramón y Cajal Fellow (both Ministerio de Educación y Ciencia programs)Peer reviewe

Effect of benzoic acid in the feed on Salmonella typhimurium in weaned pigs

The effect of benzoic acid on Salmonella Typhimurium was compared to formic acid + lactic acid in naturally infected weaners. Addition of 1% benzoic acid or 0.5% lactic acid + 0.5% formic acid did not result in a significant reduction of Salmonella prevalence, neither bacteriological nor serological, after 5 weeks of administration, compared to a control diet consisting of pelleted feed without organic acid

Traces of the last earthquake sequence (1939-1944) along NAF from lacustrine sediments

Understanding the irregularity of seismic cycles: A case study in Turke

Development of paleoseismic trench logging and dating techniques: a case study on the Central North Anatolian Fault

Understanding the irregularity of seismic cycles: A case study in Turke

Stochastic properties of water storage

August 1980.Includes bibliographical references (pages 46-48)

Lubricant study in ultrahigh vacuum and in various gas environments Final report, 26 Jan. 1965 - 15 Mar. 1966

Wear and friction of lubricated and unlubricated stainless steel bearings in sliding and rolling contact in ultrahigh vacuum and various gas environment

A Century Searching for the Neurons Necessary for Wakefulness

Wakefulness is necessary for consciousness, and impaired wakefulness is a symptom of many diseases. The neural circuits that maintain wakefulness remain incompletely understood, as do the mechanisms of impaired consciousness in many patients. In contrast to the influential concept of a diffuse “reticular activating system,” the past century of neuroscience research has identified a focal region of the upper brainstem that, when damaged, causes coma. This region contains diverse neuronal populations with different axonal projections, neurotransmitters, and genetic identities. Activating some of these populations promotes wakefulness, but it remains unclear which specific neurons are necessary for sustaining consciousness. In parallel, pharmacological evidence has indicated a role for special neurotransmitters, including hypocretin/orexin, histamine, norepinephrine, serotonin, dopamine, adenosine and acetylcholine. However, genetically targeted experiments have indicated that none of these neurotransmitters or the neurons producing them are individually necessary for maintaining wakefulness. In this review, we emphasize the need to determine the specific subset of brainstem neurons necessary for maintaining arousal. Accomplishing this will enable more precise mapping of wakefulness circuitry, which will be useful in developing therapies for patients with coma and other disorders of arousal