The study analyzed the spatial and morphological organization of mitochondria in neurons using electron microscopy of the Drosophila connectome, revealing quantitative rules for hundreds of thousands of mitochondria in thousands of neurons[1][2][3]. Mitochondria are located with an accuracy of 2–3 μm relative to synaptic and structural elements, showing systematic differences according to neuron types and compartments such as axons, dendrites, and connecting cables[1][2][3]. The morphological features of mitochondria are specific to the type of cell and neurotransmitter, thus serving as fingerprints for identification of neurons[2][3]. Longer and less round mitochondria are more commonly found in dendrites than in axons or connecting cables[1]. Differences between neuron types are as large as differences between compartments within a single neuron and coordinate across segments[1]. Mitochondrial localization correlates with regional activity and postsynaptic targets[1][2][3]. Analysis of the connectome of the mouse visual cortex confirmed cell-type-specific morphology and partially different positioning rules[1][2][3]. The results show mitochondria as organelles embedded in circuits whose distribution links subcellular architecture with brain connectivity[1][2][3].