Sensory systems are dynamically adjusted according to the animal’s ongoing needs by neuromodulators, such as neuropeptides. Neuropeptides are often widely-distributed throughout sensory networks, but it is unclear whether such neuropeptides uniformly modulate network activity. Here, we leverage the Drosophila antennal lobe (AL) to resolve whether myoinhibitory peptide (MIP) uniformly modulates AL processing. Despite being uniformly distributed across the AL, MIP decreases olfactory input to some glomeruli, while increasing olfactory input to other glomeruli. We reveal that a heterogeneous ensemble of local interneurons (LNs) are the sole source of AL MIP, and show that differential expression of the inhibitory MIP receptor across glomeruli allows MIP to act on distinct intraglomerular substrates. Our findings demonstrate how even a seemingly simple case of modulation can have complex consequences on network processing by acting non-uniformly within different components of the overall network.

感觉系统根据神经调节剂（例如神经肽）的动物持续需求进行动态调整。神经肽通常广泛分布在整个感觉网络中，但尚不清楚这些神经肽是否一致地调节网络活动。在这里，我们利用果蝇触角叶 (AL) 来解决肌抑制肽 (MIP) 是否统一调节 AL 加工。尽管 MIP 均匀分布在 AL 中，但它会减少某些肾小球的嗅觉输入，同时增加其他肾小球的嗅觉输入。我们揭示了局部中间神经元 (LN) 的异质集合是 AL MIP 的唯一来源，并表明肾小球中抑制性 MIP 受体的差异表达使 MIP 能够作用于不同的肾小球内底物。我们的研究结果表明，即使是看似简单的调制案例，也可能通过在整个网络的不同组件中表现不均匀而对网络处理产生复杂的后果。