- Top of page
- Circuits within circuits: Modulation of the crustacean stomatogastric ganglion
- The C. elegans connectome: Simple anatomy, surprising functional complexity
- Neuromodulation in flies and mammals
- Neuromodulation at fast and slow timescales is observed across evolution
- Visible wiring diagrams will interact with neuromodulators
- Conclusions and outlook: Overconnected circuits and latent circuits
Powerful ultrastructural tools are providing new insights into neuronal circuits, revealing a wealth of anatomically-defined synaptic connections. These wiring diagrams are incomplete, however, because functional connectivity is actively shaped by neuromodulators that modify neuronal dynamics, excitability, and synaptic function. Studies of defined neural circuits in crustaceans, C. elegans, Drosophila, and the vertebrate retina have revealed the ability of modulators and sensory context to reconfigure information processing by changing the composition and activity of functional circuits. Each ultrastructural connectivity map encodes multiple circuits, some of which are active and some of which are latent at any given time.