Mapping the Fruit Fly’s Brain: A Milestone in Neuroscience
Why in the news?
Scientists have successfully mapped the entire brain of an adult fruit fly, a milestone that could advance understanding of brain function and mental health treatments in humans and other animals.
Research Achievement:
- Scientists have successfully mapped the entire brain of an adult fruit fly, marking the first detailed survey of an adult animal’s brain.
- The findings, published in Nature, are a significant step toward understanding the human brain, potentially aiding in the treatment of mental health conditions like Parkinson’s and depression.
- The project involved contributions from hundreds of scientists and citizen scientists worldwide.
Methodology:
- Mapping began in 2013, with the fruit fly’s brain submerged in a chemical bath, solidifying it into a block.
- Researchers meticulously shaved off ultra-thin layers of the block and used microscopes to capture images.
- In total, they took 21 million photos across 7,050 sections to create a comprehensive brain map.
Significance of the Findings:
- Detailed more than 50 million connections among over 139,000 neurons, categorising them into 8,453 distinct types—this constitutes the largest catalogue of cell types in any brain.
- Insights gained include understanding how different cell types function, how the fly’s eyes process motion and colour, and the discovery of “hub neurons” that may enhance information flow.
- Although the human brain is more complex, fundamental communication principles among neurons remain similar, offering potential insights into human brain function.
About Drosophila melanogaster:
- Commonly known as the fruit fly; widely used in genetic, physiological, and evolutionary studies.
- Greek origin: Drosophila means “dew lover”; melanogaster means “dark gut”.
- Wild-type flies have brick red eyes and yellowish-brown bodies with black rings.
- Females are approximately 5 mm long; males are smaller and darker with distinctive sex combs.
Biology and Development:
- Development period: 7 days at 28 °C; 11 days at higher temperatures.
- Females lay around 400 eggs in decaying fruit; hatching occurs after 12-15 hours.
- Larvae complete development in 4 days, feeding on microorganisms and fruit.
- Lifespan: approximately 30 days at 29 °C.
Research Significance and Contributions:
- Ideal for genetic studies due to small size, easy culture, and short generation time (2 weeks).
- Complete genome sequenced; contains about 165 million bases and 14,000 genes.
- Thomas Hunt Morgan’s work in the early 1900s established Drosophila as a model for heredity and earned him a Nobel Prize.
- 75% of human disease genes have identifiable matches in fruit flies; used to study various diseases and biological processes, including neurodegenerative disorders and cancer.
Sources Referred:
PIB, The Hindu, Indian Express, Hindustan Times