The week in animal research w/e 07/11/14
Stem cells have been used to repair damage caused to the brain by Parkinson’s disease in rats. To simulate the disease scientists from Lund University, Sweden, killed dopamine-producing neurons on one side of the rats’ brains. Human embryonic stem cells converted into replacement neurons and injected into the rats’ brains appeared to reverse the damage. As yet there have been no human clinical trials of stem-cell-derived neurons, but the team believe that the technique could be ready for testing by 2017.
Mexican bats can interfere with the echolocation of their rivals in order to ‘steal’ their food. As one bat hones in on insect prey using sound signal, a second bat emits a ‘jamming’ signal causing the first bat to miss its target, which is then stolen by the bandit. This is the first time that this behaviour has been observed. Dr Aaron Cocoran from Wake Forest University in North Carolina said, "Nobody has seen anything like this in any other animals which echolocate. It's not necessarily surprising that they're competing with each other [for food] but the fact that they've evolved this jamming signal is quite new.”
A new form of Alzheimer’s drug as managed to sneak through the blood-brain barrier in monkeys and reduce the levels of harmful amyloid beta protein present. The drug is an double-ended anti-body, one to that interacts with the blood brain barrier to get across it, and the second that targets amyloid beta. In both macaques and monkeys the drug spread throughout the brain and decreased amyloid levels by more than 50%.
Stem cells in the mother’s milk appear to have important effects upon the developing offspring in mice, suggesting that humans might be the same. Female mice were genetically modified so that their cells contain a red fluorescent gene. The females were mated, but after giving birth they were given unmodified baby mice to suckle. Any red cells that ended up in the pups must have come from the mother’s milk. When the offspring reached adulthood red cells were found in their blood and in many tissues including the brain, thymus and pancreas, and appeared to have developed into mature cells. Researchers are now exploring the potential of breast milk as a source of stem cells for therapies, with a view to future research in macaques.
A tiny surgical device that could be used to treat a heart defect in children has been successfully trialled in pigs. The device is a long flexible tube with cutting teeth at the end that is inserted through the neck into the jugular vein and passed into the heart to cut a small hole in the wall between the two upper chambers. Surgeons use external ultrasound images to guide it to the heart, and switched on the cutting teeth remotely. Currently many operations of this kind require cutting open a child’s chest and ribs to access the heart.
The hubbub of urban life could be hindering the captive breeding of endangered rhinos. Rhinos are particularly sensitive to ‘infrasound’, frequencies far deeper than the range of human hearing. While many captive breeding environments, like zoos, may seem quiet, it may be that the level of background infrasound is disruptive to the animals.