What it is
Google Research, HHMI Janelia, the MRC Laboratory of Molecular Biology and the University of Cambridge released the connectome of an entire adult Drosophila male central nervous system: 166,700 fully proofread neurons spanning the brain and the ventral nerve cord (the insect analogue of the spinal cord), sorted into 11,710 neuron types and wired by roughly 125 million synapses. It is the largest brain map by neuron count assembled to date. The map is aligned to the earlier female brain connectome for the first synapse-resolution comparison of the sexes, which finds 8,069 neuron types shared, 138 dimorphic, 289 male-specific and 71 female-specific.
Why it matters
A connectome is a complete wiring diagram: every neuron and every synapse between them. Having the whole male CNS, brain and nerve cord together, lets researchers trace uninterrupted sensory-to-motor pathways and, for the first time, see exactly where two sexes of the same species are wired differently. The dimorphic neurons concentrate in higher brain centres while the sensory and motor periphery stays largely shared, and male-specific connections form discrete hotspots, showing how one body plan is rewired to produce sex-specific behaviour.
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Filed underconnectome, drosophila, central nervous system, sexual dimorphism, neuroscience