Systematic classification and functional analysis of neurons in, and associated with, the superior medial protocerebrum neuropil of the Drosophila brain.

• Applicant: Hannah Jones, Ph.D.
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 546644321

Despite more than a century of research on the Drosophila melanogaster brain, studies of connectivity and biological function have focused extensively on a small number of brain regions involved in sensory processing, learning and memory as well as motor control. But except for these, much of the Drosophila brain remains poorly understood regarding its functional connectivity. Systematic mapping and classification of the neuronal circuits in as yet unchartered, so-called “terra incognita” regions are needed to gain a greater understanding of the Drosophila brain functions and elucidate upstream and downstream connections of individual neurons. Neurons have unique projection patterns, which conceivably influence their information processing pathways. It is therefore critical to understand how neurons with similar or different projection patterns are organised, and how their connections are arranged in circuits. The superior medial protocerebrum (SMP) is one example of a previously unexplored neuropil in the Drosophila brain. Previous work has identified several neurons connecting the SMP with learning and memory control centres, although, much is still unknown about the function and underlying organisation of this neuropil. The proposed project aims to use single neuron data from both electron microscopy (EM) and confocal laser-scanning light microscopy (LM) datasets to build a complete neuron catalogue and connectome of this higher-order brain region and neurons associated with this region. This will involve the systematic classification of neurons into a hierarchical system that consists of families, orders, and classes of neurons. Furthermore, single neurons will be screened and examined for behavioural phenotypes using a combination of existing split-Gal4 lines and newly generated lines, aimed at behavioural profiling of subsets of neurons. This work will provide the first classification of all neurons in the SMP and associated regions, key frameworks to understand their neuronal network architecture, and the first systematic examination of the function of neurons in the SMP and associated neuropils.

• DFG Programme: WBP Position