April 2015: This Month in JoVE - Studying Locomotion in Drunken Worms, Preserving Human Liver for Transplantation, and Visualizing Bacterial Swarms

Abstract

Here's a look at what's coming up in the April 2015 issue of JoVE: The Journal of Visualized Experiments. In JoVE Neuroscience, it is clear that alcohol has profound effects on the brain. But why do different individuals respond so differently to alcohol, and why are some more prone to abuse? Some of the answers lie in our genes. In the nematode worm C. elegans, genes are easy to manipulate, and the neurobiology is simple. So it's an excellent model to study the effects of alcohol on behavior. Davies et al. use copper rings to corral worms with different genotypes on agar plates containing alcohol. They take videos of the worms at set time points and measure the locomotion of each genotype using object recognition software With this procedure, C. elegans can help unravel the molecular basis of alcohol sensitivity and tolerance, as well as the risk of abuse. In JoVE Medicine, alcohol doesn't just affect the brain; it also affects the liver, and for many patients with alcoholic liver disease, liver transplantation is the only hope. But there is a severe shortage of livers available for transplants. Therefore, Bruinsma et al. present an alternative way to preserve donor livers, which are traditionally stored statically on ice. In this new method, the donor liver is kept alive by a perfusion machine and perfused at 21°C-warmer than ice, but lower than normal body temperatures, which allows the liver to be assessed for function and transplantability. This technique may greatly expand the pool of donor livers available to patients in need of transplants. In JoVE Biology, one of the most commonly studied modes of bacterial motility is called swarming. However, the reproducibility of swarm plate assays can be difficult to achieve, so Morales-Soto et al. present a method that standardizes parameters (such as moisture content of plates) that affect swarming motility. By using bacterial strains expressing different fluorescent proteins, they can observe swarming competition dynamics between different species in a fluorescent time-lapsed video. This method can help elucidate various aspects of bacterial growth, such as how bacteria colonize different types of surfaces. In JoVE Behavior, Labots et al. demonstrate the modified hole board. This behavioral testing apparatus consists of a protected box and a board containing small cylinders. In one type of experiment, the board can be baited with tasty food rewards. In some cylinders, the treat is locked under a grid, and in differently colored cylinders, the treat is accessible. Small laboratory mammals (such as rats) are conditioned to the food reward and tested for behaviors such as object recognition or food intake inhibition. This test can help measure unconditioned behavior of small laboratory mammals and analyze their cognitive abilities. You've just had a sneak peek of the April 2015 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments.