Research Roundup: 50,000 lives saved by organ transplants, transgenic sheep aid in Huntington’s disease, smell relates to weight gain in mice, and more!

Welcome to this week’s Research Roundup. These Friday posts aim to inform our readers about the many stories that relate to animal research each week. Do you have an animal research story we should include in next week’s Research Roundup? You can send it to us via our Facebook page or through the contact form on the website.

• The UK’s National Health Service (NHS) Blood and Transplant say that 50,000 people in the UK are alive thanks to organ transplantation. This includes 36,000 kidney patients and almost 10,000 liver patients. Animal and human studies have continually improved the way we conduct transplants; in the early 1990s a transplanted kidney had a 66% chance of being functioning five years later, that figure is now 87%. The first successful liver transplant was done in dogs in 1958 by Dr Thomas Starzl, with the first human transplant following five years later. Before this was possible, many studies in dogs by Dr Roy Calne were required to improve immunosuppression drugs and prevent organ rejection. The history of organ transplant development owes much to animal studies.

• Transgenic sheep are to be used to understand early warning signs of Huntington’s disease. Huntington’s disease (HD) is a fatal genetic disorder that causes the progressive breakdown of nerve cells in the brain. The child of every parent with Huntington’s disease has a 50% chance of inheriting the disease and it is estimated that 300,000 Americans and 6,700 people from the United Kingdom suffer from Huntington’s disease. Professor Jenny Morton, from the University of Cambridge, is tackling this debilitating disease by trying to understand its early warning signs, in genetically modified sheep which carry the genetic mutation that causes Huntington’s disease. She states “Until now, much of our effort has been based on research on mice or rats, but sheep should make better research subjects. Not only do they live much longer than rodents, their brains are larger and closer in size and structure to humans.”

  

• Weight gain from eating fatty foods may be reduced – but only if you can’t smell your food. In a new study, researchers gave regular doses of diphtheria toxin to genetically modified mice which caused their sense of smell to be suppressed. These mice were then fed either a normal diet or fatty foods that induce obesity. After three months, they found that the odor deprived mice weighed slightly less than mice with their sense of smell intact. However, in the group that was fed fatty foods – they found that mice that could not smell weighed 16% less than mice that could. Interestingly, there was no difference in the amount of food that was consumed by either group or in the amount of activity in the home cage. Rather, this difference seemed to be caused by the way that they created and metabolized brown fat. In a separate experiment, looking at mice with a “sharper sense of smell”, these mice also became obese – but similar to the anosmic mice – not because of differences in the amount of food consumed. These results highlight the intimate role of smell in the process of metabolism — but it should be noted that this process may be different in humans — if simply for the amount of brown fat that we store relative to our furry counterparts. This research was published in the journal Cell Metabolism.

• The bacteria in our gut may influence our emotions. The number of reported links between our brain and our gut are increasing in frequency — and this should be of no surprise because the enteric nervous system is the second largest nervous system in our body. Previous research in mice has highlighted that the bacteria in the gut may affect your mood or emotion, including those related to anxiety and depression. Now, a similar link has been found in humans (women). Analyzing the faecal matter of 40 women, researchers identified two groups of bacteria which appeared to have an impact on the brain. In seven women whose gut primarily contained the bacterial group Prevotella, “a greater connectivity between the emotional, attentional, and sensory brain regions, while having smaller and less active hippocampi, the region of the brain that is related to emotional regulation, consciousness and the consolidation of short-term memories into long-term ones.” In contrast, in the guts of the remaining thirty three women the bacterial group, Bacteroides These women were found to have a different type of brain — “The frontal cortex and the insula – regions of the brain linked to problem-solving and complex information processing – had more gray matter than the other group of women. Their hippocampi were also more voluminous and active.”   This research was published in the journal Psychosomatic Medicine.

• Prairie dogs protected from plague by vaccine developed in field trials. In an April’s research roundup, we wrote about a vaccination campaign that was planned for prairie dogs in an effort to save the black footed ferret. Because of the Sylvatic plague, prairie dogs living in the habitats of the black footed ferret are now in danger of being decimated and spreading this disease to the ferrets that eat them. A recent study published by the Researchers at the University of Wisconsin – Madison and U.S. Geological Survey’s National Wildlife Health Center, describes that the vaccination campaign was successful. Colonies of prairie dogs that received the vaccination were twice as likely to survive than those that did not — and the odds were even higher for juvenile animals. The study aims to develop a method to control disease in endangered or threatened wildlife through the provision of vaccine-laden bait – and could later include drones and all-terrain vehicles to aid in the dispersal of the vaccination. This research was published in the journal EcoHealth.