The human-fruit fly connection

Researchers can remove a fly's brain and place it — still functioning — under a microscope. They can isolate neurons that have different functions and watch them fire -or send signals- to other neurons when stimulated.

VOA - M. Saner

A research associate at Davis' lab prepares the series of tubes for the flies' olfactory memory training.

Once they identify which neurons are firing differently in the normal flies that have learned to identify the difference, they examine the mutants that don't remember the shocking odor to see how genes control the firing process.

Fruit flies have essentially the same genes as we do, just fewer of them. Davis says that correlation is what makes his research so promising.

"If we find a gene in flies that's important for a process like memory formation, that sequence of that gene is generally conserved [across species]. We can use that gene to identify a similar gene in a mouse or in humans, because they have a very, very high sequence similarity. The bases that make up the gene are very similar." He explains that is how researchers are able to identify with a very high probability in humans the vast majority of genes that exist in fruit flies.

"We're actually quite similar to a fruit fly, believe it or not," he adds with a laugh.

VOA - M. Saner

Each vial in the storeroom can hold more than 150 flies.

Generations of flies in one room

Fruit flies have a very short lifespan compared to other laboratory animals like the mouse or rat. So, with the flies mating and reproducing every two weeks, many generations of flies can be studied in a year, allowing researchers to do genetic studies quickly. And since the flies are small, hundreds of thousands of them can be stored easily and inexpensively in plastic vials.

Davis shows off a small room at the Institute, filled with vials of fruit flies — all to be used in the search for answers to how our memories are made and stored.

"If one examines the vast majority of neurological diseases — Alzheimer's, Parkinson's and so forth, and psychiatric diseases — schizophrenia, bipolar disorder, ADHD, autism, all of these have a commonality in that they have learning disorders, in general, or memory formation seems to be an underlying feature of the vast majority of neurological and psychiatric diseases."

Davis and his team of researchers hope their work will lead to a drug that will help the brain fight learning- and memory-related diseases. He says gaining a fundamental understanding of how the learning process works could be the key to treating — and perhaps curing — them.