For many years, medical doctors and research scientists believed the human brain had a limited capacity to undergo self-renewal as it aged, where unlike other organs of the body, loss of a cell to death or damage is not followed by growth of replacements. But according to a recently-released study, the neurons making up the bulk of the brain might actually be replenished well into adulthood. As such, perhaps the public service messages advising people that you only get a fixed amount of brain cells and therefore should not use illicit drugs and alcohol because they kill neurons may be in error.
To better understand the research and its significance, here is some background information on the architecture of the human brain.
What's Left Behind By the Melting Permafrost Could Be More Dangerous Than Rising Tides, Droughts or Floods
As bad as this year’s flu epidemic has been, at least in the United States, most of us rest easy knowing that deadlier and nastier mass-murdering pathogens such as bubonic plague and smallpox live mostly in our collective memory. Or do they? As climate change melts longstanding permafrost, some scientists fear that “zombie pathogens,” which have been slumbering for centuries, might be waking up, threatening to overtake humanity again.
Permafrost refers to a layer of permanently frozen earth—it has to be frozen for a minimum of two years to qualify—found primarily in most continually frosty parts of the world such as the Arctic Circle, Greenland, Alaska and Siberia. According to National Geographic, there are some 22.8 million square miles of permafrost in the world. Research has shown that Earth's permafrost heated up by 6 degrees Celsius during the 20th century and scientists predict even more dramatic melting by 2100. Not only will this raise ocean levels and exacerbate erosion, it may also mean a release of pathogens better left frozen.
Deep in the forests of Brazil, a fungus known as Ophiocordyceps unilateralis is taking over the brains of carpenter ants and directing them to other parts of the forest that the fungus finds more hospitable.
"This so-called zombie or brain-manipulating fungus alters the behavior of the ant host, causing it to die in an exposed position, typically clinging onto and biting into the adaxial surface of shrub leaves," said the authors of a study published in the journal Plos ONE in 2011, which introduced the world to the concept of zombie ants.
Can there be life after death? Biosciences company ReAnima thinks so, and they’ve just been granted permission to find out.
An institutional review board has granted Bioquark, a life sciences company taking part in the ReAnima project, ethical permission to recruit 20 brain-dead patients for a study that will test whether stem cells can bring them back to life.