Test subjects taking part in an 8-week program of mindfulness meditation showed results that astonished even the most experienced neuroscientists at Harvard University. The study was led by a Harvard-affiliated team of researchers based at Massachusetts General Hospital, and the team’s MRI scans documented for the very first time in medical history how meditation produced massive changes inside the brain’s gray matter. “Although the practice of meditation is associated with a sense of peacefulness and physical relaxation, practitioners have long claimed that meditation also provides cognitive and psychological benefits that persist throughout the day,” says study senior author Sara Lazar of the MGH Psychiatric Neuroimaging Research Program and a Harvard Medical School instructor in psychology. “This study demonstrates that changes in brain structure may underlie some of these reported improvements and that people are not just feeling better because they are spending time relaxing.”
Sue McGreevey of MGH writes: “Previous studies from Lazar’s group and others found structural differences between the brains of experienced meditation practitioners and individuals with no history of meditation, observing thickening of the cerebral cortex in areas associated with attention and emotional integration. But those investigations could not document that those differences were actually produced by meditation.” Until now, that is. The participants spent an average of 27 minutes per day practicing mindfulness exercises, and this is all it took to stimulate a major increase in gray matter density in the hippocampus, the part of the brain associated with self-awareness, compassion, and introspection. McGreevey adds: “Participant-reported reductions in stress also were correlated with decreased gray-matter density in the amygdala, which is known to play an important role in anxiety and stress. None of these changes were seen in the control group, indicating that they had not resulted merely from the passage of time.”
“It is fascinating to see the brain’s plasticity and that, by practicing meditation, we can play an active role in changing the brain and can increase our well-being and quality of life,” says Britta Hölzel, first author of the paper and a research fellow at MGH and Giessen University in Germany
The trend of growing organs and tissues in a lab is picking up speed. The newest lab-grown breakthrough is Harvard’s “bone-marrow-on-a-chip.” The Wyss Institute for Biologically Inspired Engineering at Harvard recently published their experiment news in the journal Nature Methods.
The researchers said the invention will enable scientists to analyze the effects of drugs and certain agents on whole bone marrow without animal testing. It also allows scientists to determine how radiation hurts bone marrow and other alternatives that could help. Initial testing showed bone marrow withers under radiation unless a drug that specifically fights off radiation poisoning is involved. The chip could also serve as a temporary “home” for a cancer patient’s bone marrow while they undergo radiation treatment. Bone marrow produces all blood cell types, and the Harvard chips allow the bone marrow to perform these essential functions while “in vitro.”
This chip is one of many that the Wyss Institute team has developed, alongside lung, heart, kidney, and gut chips. To build it, the team put dried bone powder into an open circular mold the size of a coin battery. This mold was then implanted under the skin on the back of a mouse. Eight weeks later, scientists removed the mold and examined it under a microscope to find a honeycomb structure filled in the middle of the mold, looking just like natural trabecular bone. The marrow of this looked identical to normal marrow as well. It was filled with red blood cells, mimicking the marrow of the mouse. When sorting and organizing the different bone marrow blood cells, the team found the types and numbers were the same as that in a mouse thighbone. The engineered bone marrow was then placed in a microfluidic device and received a steady supply of nutrients and waste removal to imitate circulation the tissue would normally be exposed to in the body. The marrow-on-a-chip lasted in the lab for one week, long enough to test it with radiation.
Researchers are hoping this will eventually lead to growing human bone marrow in mice, as well as using the blood cells produced on these chips to help other organs grown on chips in the lab.