Living With Painless

Fruit Flies

Drosophila Flies

Drosophila is a useful model system for the identification and study of genes and gene products. When touched with a probe heated to 38 degrees Celsius, a Drosophila larva responds with a characteristic rolling action that turns the body away from the heat source. Small animals such as insects must be able to quickly detect when the body begins to overheat and respond. The rolling behavior is adaptive for larvae that suddenly experience intense heat from bright sunlight. A search produced Drosophila larvae that failed to respond to the heat probe. These larvae have a mutant painless gene: they don’t sense the heat (pain) and don’t turn away.

Further investigation has shown that painless encodes for an ion channel that is expressed and embedded in the membranes of some nerve cells. These nerve cells send multiple dendrites to areas of the cuticle, much like mammalian pain receptors send multiple dendrites into the skin. When Drosophila cuticle is heated, the painless ion channels send a signal to the nervous system. Drosophila that have mutant channels fail to send signals and fail to roll in response to the heat probe. Drosophila is a convenient system to learn about the workings of simple neural systems and apply that knowledge to human problems.

About jjneal

Jonathan Neal is a retired Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
This entry was posted in behavior, Biomaterials, by jjneal, Health. Bookmark the permalink.

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