Dr. Bortrum
10/01/2013
Off With Their Heads
CHAPTER 38 Let Them Eat Liver
Over the years, I've written about many subjects in the scientific realm, some of which have been recognized by prestigious awards such as the Nobel Prize. I probably have also written about research that was honored with an Ig Nobel Prize. For those of you unfamiliar with the Ig Nobel, the prizes are given for "achievements that first make people laugh and then make them think." However, I can't recall writing about research that I considered serious, high quality stuff that later would be recognized by an Ig Nobel Prize. Well, in the newscripts section of the September 16 issue of Chemical and Engineering News I found that one of the topics I discussed has indeed been granted that high honor in the Ig Nobel ceremony at Harvard University on September 12.
The research that I had written about concerned the work by a team of workers at Lund University in Sweden on dung beetles in Africa. The dung beetles studied by the Lund team perform a valuable service by gathering dung in little balls and taking it home for food or to use as brooding chambers. The researchers wondered how the beetles typically headed directly to their homes in relatively straight lines after harvesting their prized fecal material. In a series of interesting experiments, some involving actually using a planetarium, the Lund team showed that the beetles were actually using the Milky Way to orient themselves. The Lund team won not only the Ig Nobel prize in Biology but also the prize in Astronomy! Marie Dacke and three of her coworkers from Lund were on hand to receive their awards, which typically are presented by actual Nobel Prize winners.
The other Ig Nobel prizes were indeed humorous. The Peace Prize was shared by the president of Belarus for making it illegal to applaud in public and police in Belarus who arrested a one-armed man for applauding! Understandably, none of the Belarus awardees was present to receive this award! I found the Ig Nobel Prize for Public Health disturbing, albeit having a humorous aspect. This prize went to a team from a hospital in Bangkok, Thailand for their medical techniques used to address an epidemic of penile amputations in Siam! The medical team did not recommend their techniques be used if "the amputated penis had been partially eaten by a duck." None of the team showed up at the ceremony but their acceptance speech was read by Nobel Laureate Eric Maskin, who won his Nobel Prize in Economic Sciences.
I was intrigued by what caused the epidemic of amputated penises and went to the abstract of the referenced article by the Sinraj Hospital team in the American Journal of Surgery. I found that the epidemic was caused, as you might expect, by angry housewives performing the amputations on philandering husbands! The article discusses the reanastomosis of the amputated penile segment. I did look up the word reanastomosis - the reuniting of a divided vessel. I was about to have dinner and opted not to pursue this subject further lest it affect my appetite! It also would have cost me money to get the full text.
Speaking of amputations, in the October issue of Scientific American I found a brief article by Arielle Duhaime-Ross telling of work by Tufts University researchers on flatworms known as planarians. I had heard of various animals, such as salamanders, that are able to regenerate lost limbs or tails but the planarian flatworm is truly amazing. Cut off its head and it will grow back a new head! Slice a flatworm down the middle lengthwise and you'll grow back two individuals! This is one crazy critter. It seems that a pool of adult stem cells in the flatworms provide the source of the power to regenerate missing body parts.
What the Tufts researchers are asking in their work on the flatworms is even weirder than the regeneration. They want to know if memories can be stored in tissues other than the brain. In their research, they were following up on some work by neuroscientist James V. McConnell on flatworms back in the 1960s. McConnell posed the same question - if a flatworm were trained to form a particular memory, could that memory be restored in that flatworm after decapitation and re-growth of a new head? He and his colleagues performed numerous tests on the flatworms and decided the answer was yes. However, the experiments were very tedious and other groups were unable to reproduce his results.
A July 18, 2013 news release from Tufts and a brief article on The Node, a developmental biologists Web site, describes the work reported by Tufts biology professor Michael Levin and former post-doc Tal Shomrat, now at the Hebrew University of Jerusalem, in their paper in the Journal of Experimental Biology. Back in McConnell's day, the work on the flatworms was extremely arduous, trying to train and keep track of the flatworms' training and feeding behaviors before and after the decapitations. The Tufts workers spent five years developing new automated and computerized techniques for following and scoring the worms' behaviors. These improvements allowed fulltime 24-7 following of the worms' behaviors.
Specifically, two bunches of flatworms were studied. One group was raised in Petri dishes with smooth floors while the other group lived in Petri dishes with rough-floored Petri dishes, the floors roughened by laser-machining. Let's call the two flatworm groups the "smooth" and the "rough" groups. Next, both groups of flatworms were placed in rough-floored Petri dishes. In these rough-floored dishes, one quadrant of each dish was illuminated with a blue light, which flatworms normally try to avoid. However, in the lighted quadrant the researchers placed some liver. I don't know what kind of liver, calves' or beef or some other. For the worms to get their food reward, they had to overcome their dislike of light and ascertain that the food was in the lighted quadrant. Before settling down to eat, the flatworms usually spend a good bit of time exploring the dishes before they feel comfortable having a meal.
In this experiment, the rough group of flatworms spent less time exploring their familiar rough environment and more time eating liver than the smooth group, placed on this unfamiliar rough flooring. OK, now for the guillotine, or whatever they use to chop off a flatworm's head. Both groups were beheaded and placed in smooth-floored dishes for a couple of weeks until new heads were re-grown. When the two groups with their new heads were retested the rough group worms were just a bit quicker in getting to the lighted food chamber. The slight difference in behavior of the two groups was not considered significant. However, when both groups were given a brief training session in the rough-floored dishes and then retested four days later, the rough group was significantly faster getting to the lighted chamber and spent more time chowing down on that liver!
The bottom line is that there does indeed seem to be a preservation of memory that is stored somehow in cells of the worms' bodies other than those in their brains. How this is possible is still a mystery but it looks like McConnell was on the right track way back in the 1960s. If the Tufts experiments are confirmed and there is indeed some sort of extra-brain memory storage, it opens up possibilities that some day we might be able to bring back memories after brain injuries. Meanwhile I think you can be sure that there will be a good bit of experimenting with those remarkable flatworms in the near future. If I weren't so old, I'd be tempted to latch on to a few of the critters myself. I also have one question that I didn't find the answer to. Did the severed heads re-grow bodies? On Googling this topic I find there's a good bit of work going on indicating that a particular gene, the Wnt gene, is involved in determining whether the head or some other part of the body is regenerated. The work is already going on and apparently has been for quite some time. The Holy Grail, of course, would be to be able to control re-growth and reattachment of such things as spinal cord injuries and the like.
Finally, an update for those of you who might be considering hip replacement surgery, my new hip (via anterior hip replacement surgery on July 2) has been working fine and I'm back to golfing with our Old Guard group on our nine-hole par-3 course. Last week, in my third round of the year, I had two birdies, which matches my total number of birds for the whole season last year. Not to brag, but I also won the "closest-to-the-pin" prize last week and sank the 7-and-a-half foot putt for my birdie on that hole. Full disclosure - after my birdie-par-birdie start, reality set in and I finished the nine holes 10 strokes over par! The hip was fine.
Next column should be posted on or about November 1.
Allen F. Bortrum
