Brain Linked to Immune System

A physical link has been discovered between the human brain and a lymphatic system through a series of vessels previously thought not to exist, raising new questions about the connection to and causes of many neurological diseases and their dysfunction.

Bacteria in Healthy Placentas

Long thought to be sterile, a new study has found that the placenta is home to a non-pathogenic bacterial community that is similar to that found in the mother's mouth and that may be linked to poorly understood pregnancy disorders.

New Layer of Cornea Discovered

Researchers have found a previously unknown and distinct tough sixth layer (named the Dua's layer after its discoverer) in the cornea of the human eye, located at the back of the cornea with a thickness of only about 15 microns.

New "Glymphatic System" in Brain

Neuroscientists have discovered a previously unknown system that rapidly drains waste away from the brain, a waste clearance network named the "glymphatic system" that shadows the blood vessels and operates much the same way as the lymphatic system in the rest of the body.

Motion Cameras Detect Autism

Researchers are using the motion-detection camera from Microsoft's commercial gaming system Kinect to observe young children at play and detect early signs of autism spectrum disorder, tracking each child's motion and activity level as an aid to professional diagnosis.

Human Urine Not Sterile

Researchers have identified live bacteria in the urine of a sample of healthy women, challenging the long-held notion that human urine is a sterile substance.

Nose Reveals Time of Death

Researchers have discovered the tiny cilia inside the human nose continue to pulse in a predictable rate up to 20 hours after death and are relatively unaffected by environmental factors, providing an additional tool for forensic investigators.

Stronger Immunity in Women

A new study of the X chromosome shows it contains up to 10% of all microRNA yet known of the human genome, which have important functions in immunity and cancer and may explain why women (XX) generally have stronger immunity and disease resistance than men (XY).

Yawning Cools the Brain

A new study shows that yawning varies with season and ambient temperature, suggesting that regulating brain temperature may be one of the purposes of this poorly understood phenomenon.

Three Gut Ecosystems

Researchers have found only three broad enterotypes of bacteria (dubbed bacteriode, prevotella and ruminococcus after the dominant species) exist in the human gut worldwide regardless of physical variations in race, age, geography or diet.

2500-Year-Old Brain

A 2500-year-old human brain found in York in 2008 has been dated to a hanged and decapitated individual between 673 and 482 B.C., the soft tissue remarkably preserved by being "pickled" due to a quick burial separate from the body in low-oxygen mud.

Gut Bacteria and Human Brain

Researchers have uncovered a bidirectional "cross-talk" communication between the flora living in the human gut and the way the brain is wired that influences anxiety-related behaviors and may relate to psychiatric illness, intestinal diseases and metabolic disorders such as obesity.

Artificial Ovary Developed

Researchers have developed the first functional artificial human ovary composed of a three-dimensional model from donated tissue containing all three ovarian cell lines, with the prototype able to mature human oocytes from early antral follicle to full maturity.

Mammals Make Morphine

New research shows that mammals, including humans, are capable of naturally producing trace amounts of the narcotic morphine in their bodies, leading to questions of how and why such a complicated and costly chemical process evolved.

Women Smell Better

Women's sense of smell is significantly better than men's with regard to body odor, which may indicate their ability to collect biologically relevant health information from potential mates.

Global Survey of Oral Microbes Completed

Researchers at the National Institutes of Health have completed the first in-depth study of the global diversity of the human oral microbiome.

More than 600 different species of bacteria were found to live in human saliva, with the composition of each person's oral microbiome as unique as a fingerprint. Samples were studied from six geographic areas around the globe and the microbiome of each was found not to vary significantly, regardless of location, ethnicity or diet. This research is part of a recent initiative to study the microbiomes of several areas of the human body, with previous work focusing on the intestines and skin.

The human body harbors ten times more foreign microorganisms than body cells. As the mouth is the ideal gateway for foreign entry into the body, an easily obtained saliva sample is valuable for the study of the health effects disease, diet or cultural factors. It could also lead to the analysis of human migrations and populations around the world.

These results were published in the February 27th edition of Genome Research.

Source: ScienceDaily

Earliest Human Footprints Found in Kenya

Scientists from Bournemouth University have discovered fossil evidence of the oldest "modern" human footprints near Ileret in northern Kenya.

Estimated to be 1.5 million years old, these Homo erectus footprints are not the oldest found belonging to the human lineage. However, these Kenyan footprints are the oldest to display the shape and gait of modern humans, having a pronounced arch and short, aligned toes. Older footprints display relatively flat feet and a gap between the big toe and the others, a foot more designed for grasping instead of walking.

The footprints also reveal clues as to how Homo erectus walked, with a heavy landing on the heel, transferring weight to the outer edge of the foot and then pushing off with the toes. This method is very much like our modern gait and very different from older Australopithecus footprint records. The fossil record is distinctly lacking in feet and hands, as the smaller bones are easily eaten or destroyed by carnivores and scavengers.

These results were published in a recent edition of Science.

Source: BBC News

Research Reveals Why Hair Turns Gray

Researchers at the Federation of American Societies for Experimental Biology (FASEB) have discovered the reason that hair turns gray as we age.

Gray hair results from a natural build-up over time of hydrogen peroxide (H₂O₂) in hair follicles, essentially bleaching the hair from within. This accumulation is cause by a reduction of a certain enzyme called catalase that breaks down hydrogen peroxide into water and oxygen. Hair follicles cannot repair the damage caused by hydrogen peroxide because of low levels of other enzymes methionine sulfoxide reductase (MSR) A and B that normally serve this function.

At the same time, the high levels of hydrogen peroxide and low levels of MSR A and B also disrupt the formation of the enzyme tyrosinase, which is responsible for the production of the natural pigment melanin. Researchers also speculate that a similar process is responsible for loss of pigment in certain skin conditions such as leukoderma.

These results were published in a recent edition of the FASEB Journal.

Source: ScienceDaily

New Brain Area Developed in Primates for Small Motor Skills

Scientists at the University of Pittsburgh School of Medicine and Pittsburgh's Veterans Affairs Medical Center have identified a new area of the primate brain that evolved to enable the use of tools and other small, fine motor skills.

Most animals' primary motor cortex of the brain controls all movements indirectly via the pathways through the spinal cord. However, in human and higher primate brains researchers discovered another area located just outside the motor cortex that consists of specialized corticomotoneuronal cells. These cells control spinal cord motor neurons directly, specifically the neurons responsible for muscle movement in the shoulder, arm and hand.

The spinal neural structure is much the same in most vertebrates, but these corticomotoneuronal cells permit human and other primates brains to bypass the limitations imposed by greater spinal cord pathways and control these muscles directly. This allows the development of fine motor control necessary for the use of tools, throwing a ball or playing musical instruments.

Also discovered in this study is that these corticomotoneuronal cells are not present at birth but instead develop during the first months of life and become mature at about two years of age. The growth and progress of an infant's early motor skills is due to the establishment of these connections.

These results were published recently in an online edition of the Proceedings of the National Academy of Sciences.

Photo: LiveScience