Looking for a better answer for amputees, researchers have turned to nature’s expert in limb regeneration, the salamander. The human body initially reacts similarly to that of a salamander. We immediately form a scar to prevent the open wound from infections and major blood loss, but our bodies stop there. Unlike the salamanders, we cannot reactivate or naturally form a blastema to regenerate a new limb in a few weeks.
Scientists and engineers at MIT are striving to change the design of artificial limbs which are difficult to use and extremely painful. Their efforts are benefiting from studies on a very curious insect model: the horsehead grasshopper that can move its limbs without relying on any muscles. They studied denervated grasshopper limbs that were flexed at different angles and found that a “passive joint force” moves limbs to their original positions when flexed.
Normally when studying disorders that cause blindness in humans, scientists genetically disable cone-related genes in small animals like mice. Studying nine-banded armadillos would give scientists a much more realistic model to test viable treatment options, such as gene therapy, a method of correcting a genetic disease by replacing defective genes with corrected copies. If gene therapy were able to correct the nine-banded armadillo’s cone-related mutations, it could be adapted to correct forms of human blindness.
Snails respond to stress like mammals do. Similar stress responses in both humans and snails make the snail a perfect animal model for researchers studying this constant factor in our lives. Researchers found that when snails must cope with strenuous and varied stressors, their memory stops working. In the study, snails became stressed when they experienced low levels of calcium, needed for proper shell growth, and when the presence of other snails caused overcrowding.
After the Burmese python gorges on massive quantities of food, its metabolism increases by about 40% and its organs enlarge: its gastrointestinal tract doubles in size, and its heart cells swell by about 40%. No new tissue is generated — the cells grow in a process called hypertrophy. The enlarged heart of the python is not unlike that of the human athlete, heavily muscled and extremely capable. Despite ingesting immense volumes of fat, the heart of the Burmese python never seems to suffer from plaque buildup.
The study of ferrets has been instrumental in the efforts of researchers to uncover viable treatment options for SARS. Due to the similarity of the lung physiology of ferrets and humans, researchers have been using the ferret model for research into the influenza virus. In recent years, scientists have discovered that ferrets are able to contract SARS. The disease is able to replicate efficiently in the respiratory tracts of ferrets just as it does in that of humans.