Researchers trained fruit flies to correlate a particular odor with a mild electric shock. Much like Ivan Pavlov's drooling dog experiment, the flies began to avoid the odor.
The odor stimulated nerve cells known as "gamma lobe neurons" in the flies' brains and the conditioning caused changes in the cell activity, or a "memory trace." The cells were less responsive to the odors when not accompanied by the electric shock, compared with the response when odors were accompanied by a shock.
“Memory is essential to our daily function and is also central to our sense of self,” said Gregg Roman, associate professor of biology and biochemistry at the University of Houston. “To a large degree, we are the sum of our experiences. When memories can no longer be retrieved or we have difficulty in forming new memories, the effects are frequently tragic."
Researchers were able to identify a single protein, heterotrimeric G(o), that is responsible for the memory trace. Protein removal led to poor learning and memory formation in the fruit flies, showing that inhibiting the protein is essential to memory storage.
While the fruit fly brain is simpler than ours, it does function comparably when it comes to memory formation, storage, and retrieval. Studies suggest the fly brain has similar connections to the human brain, meaning it responds much the same to internal and external stimuli.
A recent study found changing the diet of fruit flies helped reverse age-related memory loss and improved learning.
The study authors believe this new finding could help our understanding of human memory and the treatment of dementias in the future.