Ciencia actual

Aquí les dejo dos enlaces muy interesantes. El primero, los llevara a  "Genome Biology", y nos descubre el funcionamiento de un reloj biológico dentro del material genético. Se trata de un trabajo fundamental por sus aplicaciones en el conocimiento del desarrollo de patologías de la vejez y también de los mecanismos del envejecimiento.

El otro trabajo aparece en "Science" y tiene que ver con la importancia del sueño en la fisiología del sistema nervioso central. Todos los animales duermen, de una u otra forma, así que el valor homeostático del sueño no es exclusivo del ser humano. Para decirlo en palabras sencillas, durante el sueño se produce un proceso de limpieza de toxinas. Ya se sabía que dormir bien era sano, necesario y que algunas enfermedades graves cursan con alteraciones del sueño. Ahora un modelo experimental ha descubierto parte de los efectos moleculares del sueño en mamíferos.

"Writing in the journal Genome Biology, Horvath showed that the biological clock was reset to zero when cells plucked from an adult were reprogrammed back to a stem-cell-like state. The process for converting adult cells into stem cells, which can grow into any tissue in the body, won the Nobel prize in 2012 for Sir John Gurdon at Cambridge University and Shinya Yamanaka at Kyoto University.

"It provides a proof of concept that one can reset the clock," said Horvath. The scientist now wants to run tests to see how neurodegenerative and infectious diseases affect, or are affected by, the biological clock.

"These data could prove valuable in furthering our knowledge of the biological changes that are linked to the ageing process," said Veryan Codd, who works on the effects of biological ageing in cardiovascular disease at Leicester University. "It will be important to determine whether the accelerated ageing, as described here, is associated with other age-related diseases and if it is a causal factor in, or a consequence of, disease development".

Sleep Drives Metabolite Clearance from the Adult Brain

1. Lulu Xie1,*, 
2. Hongyi Kang1,*, 
3. Qiwu Xu1, 
4. Michael J. Chen1, 
5. Yonghong Liao1, 
6. Meenakshisundaram Thiyagarajan1,
7. John O’Donnell1, 
8. Daniel J. Christensen1, 
9. Charles Nicholson2, 
10. Jeffrey J. Iliff1, 
11. Takahiro Takano1, 
12. Rashid Deane1,
13. Maiken Nedergaard1,†

+Author Affiliations

1. ¹Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY 14642, USA.
2. ²Department of Neuroscience and Physiology, Langone Medical Center, New York University, New York, NY 10016, USA.

1. ↵†Corresponding author. E-mail: nedergaard@urmc.rochester.edu

The conservation of sleep across all animal species suggests that sleep serves a vital function. We here report that sleep has a critical function in ensuring metabolic homeostasis. Using real-time assessments of tetramethylammonium diffusion and two-photon imaging in live mice, we show that natural sleep or anesthesia are associated with a 60% increase in the interstitial space, resulting in a striking increase in convective exchange of cerebrospinal fluid with interstitial fluid. In turn, convective fluxes of interstitial fluid increased the rate of β-amyloid clearance during sleep. Thus, the restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.