# Applying functional MRI analysis techniques to whole-brain calcium-imaging data to investigate structural and functional relationships in Drosophila melanogaster

Article · Takuto Okuno, Alexander Woodward, Hideyuki Okano, Junichi Hata

- Archive id: doi:10.1101/2025.07.01.662601
- Published: 2025-07-04
- Venue: bioRxiv (Cold Spring Harbor Laboratory)
- DOI: https://doi.org/10.1101/2025.07.01.662601
- Citations: 0
- Source URL: https://doi.org/10.1101/2025.07.01.662601
- Provenance: openalex

## Abstract

Abstract Clarifying the relationship between structure and function is important for understanding the brain. In Drosophila melanogaster , FlyEM and FlyWire electron microscopy-based connectome data and whole-brain calcium imaging data are available. We applied pre-processing methods from fMRI to whole-brain calcium imaging data and comprehensively investigated the optimal parameters. Then, we found that the FC-SC (functional and structural connectivity) correlation decreased linearly with region of interest count, and this trend was the same in flies and humans. We also developed a new, more robust method to quantify the degree of pre-and post-synaptic segregation and investigated this in the fly whole-brain. This revealed that many neurons have unsegregated synapses. We extracted highly unsegregated synapses and compared them with random-extracted null SC matrices. Their FC-SC correlation was significantly higher, indicating that these synapses contribute to FC well. Conversely, highly segregated-synapses showed significantly lower FC-SC correlation and contribute less to FC. Neurons with unsegregated synapses like non-spiking neurons are spread throughout the whole-brain, and they are thought to have a significant influence on FC.

_Abstract reproduced under CC-BY (publisher license, via OpenAlex)._

Topics: [Connectomics & Brain Mapping](https://space-kitty.com/topics/connectomics)

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