We don’t really give fruit flies much thought. We give even less thought to whether they can smell.

It turns out that they have a sense of smell, and a West Virginia University researcher is using that sensation to understand how human nervous system response can be altered.  The project is funded for three years by a grant from the National Institutes of Health (NIH).

Andrew Dacks, assistant professor in the WVU Department of Biology, said altering the way a neuron responds to stimulus, known as neuromodulation, offers the nervous system flexibility. Neuromodulation occurs throughout the nervous system and, not surprisingly, is critical for healthy brain function.

“You could have a road map of the town of Morgantown, but without knowing the time of day, time of year or weather conditions, you will never be able to predict the amount of time it will take to drive from the Suncrest Towne Centre to Dorsey’s Knob Park. The map stays the same, but the way cars are able to travel on the map is altered,” he said.

“That’s what neuromodulation gives you — flexibility to adjust how a neural network functions in different situations.”

As Dacks maps out which neuromodulatory receptors influence which neurons using the fruit flies, he said he’s able to determine the effects on how the nervous system processes information. The implications could ultimately reveal general principles about the human nervous system.

Many groups of neurons in a nervous system express the same neuromodulatory receptor, making it challenging to understand how a receptor expressed by one group of neurons contributes to the total effects of neuromodulation.

“Let’s say a receptor is expressed in the part of the nervous system that controls walking and the sense of smell, and you get rid of this receptor throughout the whole body of the animal,” Dacks said.

“Lo and behold, the animals are no longer attracted to the odor. Is that because they can’t walk properly anymore? Or is it because it’s affected their sense of smell?”

Using fruit flies, it is possible to manipulate neuromodulatory receptors expressed in specific groups of neurons without affecting the rest of the nervous system, he said.

“This allows us to have a highly directed approach where we can target our manipulation right to specific parts of the brain.”

Exploring the nervous system of the fruit fly, Dacks said, has allowed his team to study the consequences of neuromodulation for odor coding.