Prion diseases are a group of severe conditions that affect the nervous system of many animals, including humans. Although their causes were highly controversial, there is a widespread agreement nowadays that they are originated and transmitted by prions, infectious agents with a normal and an abnormal structure. The abnormal prion protein infects the host animal […]
Humans are naturally social. Yet, the modern way of life in developed countries is greatly reducing the quality and quantity of social relationships despite the use of modern technologies that provide an illusory richness of interpersonal contacts. Many people in industrialized nations live far from their relatives, delay getting married, and more and more people […]
Stammering, stuttering or alalia literalis is a speech disorder characterized by involuntary repetition and prolongations of sounds, syllables, words or phrases and involuntary silent pauses or blocks where the affected person is unable to produce sounds. Around 1-in-20 children aged 2 to 5 years old will stammer at some moment, but most grow out of […]
Anthropology • Biology • Evolution • Genetics
Neanderthals ( Homo neanderthalensis ) were a species –some say a subspecies although most authors consider there is enough evidence to consider them as a separate species– of human closely related to us. They were firstly discovered in a cave in the Neander Valley («Tal» in German), about 12 km east of Düsseldorf. There is […]
Neurogenesis is the process by which neurons are generated from neural stem cells and progenitor cells. It is a crucial part of neural development and is most active during pre-natal life, being responsible for populating the growing brain with neurons. Zika virus is an emerging mosquito-borne and sexually-transmitted flavivirus that was first identified in Uganda […]
Hibernation is a state of inactivity and metabolic depression used by some mammals to survive a cold winter. It may last several days, weeks, or months depending on the species, environment temperature, season, and individual’s body condition. Usually, hibernating animals survive the energetic bottleneck of the winter by building stores of body fat in late […]
The blood-brain barrier is one of the defenses of the central nervous system. It is made of a thin layer of endothelial cells closely fitted together by tight junctions, being a mandatory pass between the blood and the neural cells. Thus, this barrier, considered the last great biochemical barricade in the organism, separates the blood […]
Suicide is one of the worst health and social problems in the modern world. Hundreds of millions of persons experience suicidal thoughts every year and between 10 and 20 millions went on to attempt suicide. In Spain, although the average risk is lower than in Northern countries, almost 4.000 persons die every year by their […]
Chimera was a monster from the Greek mythology, a hybrid creature usually depicted as a lion, with the head of a goat arising from its back and a tail ending in a snake. In biology, the term «chimera» is used for a single organism with genetically distinct cells from two different zygotes, also a hybrid […]
In multicellular organisms, embryonic stem cells develop into any of the different cell types that will form the adult, and along the development, they silence or activate different parts of the genome, giving rise to distinct cell identities, which are maintained throughout adult life by epigenetic mechanisms. A similar procedure may be at work at […]