Shocked snails and the wonders of RNA

Researchers at UCLA say they transferred memories between marine snails through injections of RNA.

RNA is a messenger substance that takes genetic instructions from DNA and delivers them to the protein-making machinery in cells. God designed RNA with a multitude of functions, and scientists continue to marvel at new discoveries that shed light on its varied purposes. Recent discoveries show RNA helps some species adapt to their environments more efficiently than the random DNA mutations Darwinian evolution predicts. In the current study, published in the online journal eNeuro, marine biologists demonstrated that RNA may play an integral role in memories.

The biologists gave electrical shocks to the tails of a group of snails. The snails responded with the self-protective reflex of contracting their gills and siphons (appendages that draw water over the gill for respiration). Another group of snails did not receive any shocks.

Later, the researchers tapped the snails and discovered the previously shocked snails displayed gill and siphon contractions for an average of 50 seconds, compared to only about one second for those who received no shocks. The snails’ reactions suggested the shocked group remembered the trauma and tried to protect themselves.

Next, the biologists extracted RNA from the nervous systems of the shocked snails and injected it into seven non-shocked snails. Those snails displayed an average 40-second contraction when tapped, behaving as though they remembered receiving shocks when in reality they had not. “It’s as though we transferred the memory,” David Glanzman, senior author of the study, said in a statement.

Finally, the researchers removed sensory nerve cells from the snails that did not receive shocks. When the researchers added the cells to petri dishes containing RNA from shocked snails, the nerve cells showed increased excitability. But when they placed neurons in dishes containing RNA from the non-shocked group, they noted no such increase. The discovery suggests RNA somehow stores at least some memories in chemical form.

The researchers believe this finding will aid scientists in developing ways to treat disorders involving memory. “I think in the not-too-distant future, we could potentially use RNA to ameliorate the effects of Alzheimer’s disease or post-traumatic stress disorder,” Glanzman said.

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Unintended consequences of DDT ban

U.S. media quickly blamed global warming for the significant increase in insect-borne illnesses that the Centers for Disease Control and Prevention recently reported. But according to a recent review by Just Facts, a nonprofit research institute, the 1972 federal ban on the insecticide DDT bears most of the responsibility for the alarming statistics.

News outlets such as Scientific American, Politico, and Think Progress attributed the increasing rate of insect or vector-borne illnesses such as Lyme disease and West Nile virus to global warming, and a 2016 CDC report clearly laid the blame on climate change, too. But the tide may be turning. The latest CDC report made no mention of climate change. During a conference call, Lyle Peterson, director of the CDC’s vector-borne diseases division, noted that although warmer temperatures may play a role, many different factors such as travel and trade contribute to the problem.

Just Facts highlighted several scientific studies that demonstrated the rate of vector-borne illnesses increased in conjunction with the federal ban on DDT. A 2016 study published in Nature indicated that growth in mosquito populations over the past 50 years does not correspond with rising global temperature but does correlate with decreased DDT use.

A paper appearing in the journal Lancet in 2012 noted that scientific data do not show a connection between global temperature and vector-borne illness. And another article, in the British Medical Journal in 2000, described how DDT eradicated malaria from the United States and Europe and reduced rates by more than 99 percent in other countries. Its effects continued for decades even after the ban. In New York state it took 40 years, but eventually mosquito populations returned to pre-DDT levels. —J.B.

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A CFC mystery

Emissions of the ozone-depleting chemical CFC11 have risen in the past five years despite an international ban, according to a recent research study published in Nature. Although the source of the emissions remains a mystery, scientists believe the measurements may reflect illegal production.

Manufacturers began to use chlorofluorocarbons (CFCs) in the 1930s as aerosol spray propellants, solvents, and refrigerants. These chemicals can remain in the atmosphere for up to 50 years. In the early 1970s, scientists began to understand that CFCs can destroy the ozone layer that protects the Earth from harmful radiation.

When scientists discovered an ozone hole over Antarctica in 1987, countries around the world agreed to ban the use of these chemicals. As emissions fell, the hole in the ozone began to shrink. But, much to the bewilderment of scientists, in 2013 emissions of CFC11, the second most common CFC, started to rise and now measure at the same level they did 20 years ago. Since 2006 most countries reported close to zero production of CFC11, but the study found a release of about 14,300 tons annually over the past five years.

“It’s the most surprising and unexpected observation I’ve made in my 27 years of measurements,” Stephen Montzka, lead author of the study, said in a statement.

Measurements indicate the emissions appear to come from East Asia, Nature reported. Ross Salawitch, an atmospheric scientist at the University of Maryland, blamed the emissions on “rogue production” and noted that if it continued, “the recovery of the ozone layer would be threatened.”

Because nature removes 2 percent of the total amount of CFC11 from the air each year, atmospheric concentrations of the chemical continue to fall despite the increase of emissions, Montzka said, but the decrease is much slower than scientists expected. —J.B.

Plastic surgeons grow ear in an arm

Plastic surgeons at William Beaumont Army Medical Center in El Paso, Texas, grew an ear in the arm of a 19-year-old soldier who completely lost hers in a car accident. It is the first time the Army has performed this type of total ear reconstruction.

The surgeons harvested cartilage from the soldier’s ribs and formed it into a new ear. Then they placed the cartilage under the skin of the patient's forearm to allow it to grow and form blood vessels and nerves. When the process is complete, they will remove it from the patient’s arm and transplant it. After rehabilitation, the patient’s ear should possess feeling and look close to normal.

“The whole goal is by the time she’s done with all this, it looks good, it’s sensate, and in five years if somebody doesn’t know her they won't notice,” chief surgeon Lt. Col. Owen Johnson III said in a statement. —J.B.

Millions of babies saved

James Harrison, an Australian man affectionately known as the “Man with the Golden Arm,” regularly made blood donations over the past half-century that helped save the lives of an estimated 2.4 million babies, The New York Times reported.

At age 14, Harrison required surgery and life-saving blood transfusions. When he became an adult he decided to become a blood donor out of gratitude and despite a fear of needles. Then medical professionals discovered his blood contained a rare antibody required to make a medication to save the lives of babies in danger of developing hemolytic disease, a potentially fatal condition. Only about 160 donors with the rare antibody exist in Australia.

Now after 1,173 blood donations in the past six decades, doctors say the 81-year-old needs to stop donating for the sake of his own health. —J.B.