Lifeboat Foundation

The neocortex is the part of the brain that enables us to speak, dream, or think. The underlying mechanism that led to the expansion of this brain region during evolution, however, is not yet understood. A research team headed by Wieland Huttner, director at the Max Planck Institute of Molecular Cell Biology and Genetics, now reports an important finding that paves the way for further research on brain evolution: The researchers analyzed the gyrencephaly index, indicating the degree of cortical folding, of 100 mammalian brains and identified a threshold value that separates mammalian species into two distinct groups: Those above the threshold have highly folded brains, whereas those below it have only slightly folded or unfolded brains. The research team also found that differences in cortical folding did not evolve linearly across species.

The Dresden researchers examined brain sections from more than 100 different mammalian species with regard to the gyrencephaly index, which indicates the degree of folding of the neocortex. The data indicate that a highly folded neocortex is ancestral – the first mammals that appeared more than 200 million years ago had folded brains. Like brain size, the folding of the brain, too, has increased and decreased along the various mammalian lineages. Life-history traits seem to influence this: For instance, mammals with slightly folded or unfolded brains live in rather small social groups in narrow habitats, whereas those with highly folded brains form rather large social groups spreading across wide habitats.

A threshold value of the folding index at 1.5 separates mammalian species into two distinct groups: Dolphins and foxes, for example, are above this threshold value – their brains are highly folded and consist of several billion neurons. This is so because basal progenitors capable of symmetric proliferative divisions are present in the neurogenic program of these animals. In contrast, basal progenitors in mice and manatees lack this proliferative capacity and thus produce less neurons and less folded or unfolded brains.

To an untrained observer, the electrical storm that takes place over the brain’s neural network seems a chaotic flurry of activity. But as neuroscientists understand it, the millions of neurons are actually engaged in a sort of tightly choreographed dance, a tango of excitatory and inhibitory neurons. How is this precise balance that makes normal function possible achieved during development? And how does it go wrong in diseases like epilepsy when brain activity goes out of control?

Focusing on the cerebral cortex, the part of the brain controlling thought, sensory awareness, and motor function, a group of Harvard Stem Cell Institute (HSCI) researchers in the Department of Stem Cell and Regenerative Biology (SCRB), led by Assistant Professor Paola Arlotta, has discovered that excitatory neurons control the positioning of inhibitory neurons in a process that is critically important for generating balanced circuitry and proper cortical response.

Professor Takao Hensch, a collaborator on the study in the Harvard Center for Brain Science, Department of Molecular & Cellular Biology (MCB), had previously shown that the maturation of this circuit balance triggers critical periods of brain development. Certain inhibitory cells appear particularly vulnerable to genetic or environmental factors in early life, contributing to mental illness, such as schizophrenia or autism spectrum disorders.

A brain-building genetic mutation might have helped give us an intellectual leg up on other hominins. Plus, why NASA’s Artemis Moon launch is delayed and all about an affirmative-action strategy to boost female faculty numbers.

According to a new meta-analysis, gene variants associated with a person’s blood type may be linked to their risk of early stroke.

“Non-O blood types have previously been linked to a risk of early stroke, but the findings of our meta-analysis showed a stronger link between these blood types with early stroke compared to late stroke, and in linking risk mostly to blood type A,” said study author Braxton D. Mitchell, PhD, MPH, of University of Maryland School of Medicine in Baltimore. “Specifically, our meta-analysis suggests that gene variants tied to blood types A and O represent nearly all of those genetically linked with early stroke. People with these gene variants may be more likely to develop blood clots, which can lead to stroke.”

48 studies on genetics and ischemic stroke from North America, Europe, and Asia were reviewed in the meta-analysis. 16,927 people with stroke and 576,353 people who did not have a stroke were included in the studies. Of those with stroke, 5,825 people had early onset stroke and 9,269 people had late onset stroke. Early onset stroke was defined as an ischemic stroke occurring before age 60 and late-onset stroke was older than 60 years old.

An alzheimer’s-proof brain: a groundbreaking case.

In a groundbreaking case researchers from the Massachusetts General Hospital have discovered a gene variant that seems to have disrupted the pathology of Tau Protein. The case of Aliria Rosa Piedrahita de Villegas.

Continue reading “Groundbreaking Alzheimer’s Case: Gene APOE3” »

Researchers have created a way for artificial neuronal networks to communicate with biological neuronal networks. The new system converts artificial electrical spiking signals to a visual pattern than is then used to entrain the real neurons via optogenetic stimulation of the network. This advance will be important for future neuroprosthetic devices that replace damages neurons with artificial neuronal circuitry.

A prosthesis is an artificial device that replaces an injured or missing part of the body. You can easily imagine a stereotypical pirate with a wooden leg or Luke Skywalker’s famous robotic hand. Less dramatically, think of old-school prosthetics like glasses and contact lenses that replace the natural lenses in our eyes. Now try to imagine a prosthesis that replaces part of a damaged brain. What could artificial brain matter be like? How would it even work?

Creating neuroprosthetic technology is the goal of an international team led by by the Ikerbasque Researcher Paolo Bonifazi from Biocruces Health Research Institute (Bilbao, Spain), and Timothée Levi from Institute of Industrial Science, The University of Tokyo and from IMS lab, University of Bordeaux. Although several types of artificial neurons have been developed, none have been truly practical for neuroprostheses. One of the biggest problems is that neurons in the brain communicate very precisely, but electrical output from the typical electrical neural network is unable to target specific neurons. To overcome this problem, the team converted the electrical signals to light. As Levi explains, “advances in optogenetic technology allowed us to precisely target neurons in a very small area of our biological neuronal network.”

Circa 2015 face_with_colon_three

The disease is linked to genetic changes on the evolutionary road from ape to human.

Circa 2005 Bacteria that is resistant to radiation could lead to better radiation resistance in humans.

Relatively little is known about the biochemical basis of the capacity of Deinococcus radiodurans to endure the genetic insult that results from exposure to ionizing radiation and can include hundreds of DNA double-strand breaks. However, recent reports indicate that this species compensates for extensive DNA damage through adaptations that allow cells to avoid the potentially detrimental effects of DNA strand breaks. It seems that D. radiodurans uses mechanisms that limit DNA degradation and that restrict the diffusion of DNA fragments that are produced following irradiation, to preserve genetic integrity. These mechanisms also increase the efficiency of the DNA-repair proteins.

Using gene modification techniques, a team of researchers have come up with a new treatment for balding, Wired reports — a condition experienced to varying degrees by two-thirds of American men by age 35.

The team, associated with the University of California, Irvine and a biotech company called Amplifica, believes they’ve identified the signaling pathway that drive hair growth to find new ways to stop stem cells from giving up on producing hair follicles.

Experiments with mice, as detailed in a new paper published in the journal Developmental Cell last month, have been promising. The mice were genetically modified to have the hair growth signaling pathway turned on permanently.