The Neuromodulatory Connectome: Wire and Wireless Networks

The synaptic connectome of the nematode C. elegans has been mapped completely, and efforts are ongoing to map the connectomes of other animals. However, chemical synapses represent only one of several types of signaling interaction in the nervous system. In particular, neuromodulation by monoamines, neuropeptides, or classical neurotransmitters is widespread and often occurs extrasynaptically between neurons not connected by wired synapses. In C. elegans, it is feasible to map these neuromodulatory networks comprehensively and at a single-cell level and examine how wired and wireless signaling interact. In this talk, I will describe what we have learned about the functional organisation of neuromodulatory circuitry involved in the control of behavioural states such as arousal, as well as our ongoing efforts to map extrasynaptic connectome networks comprehensively in the worm. In addition, I will discuss our identification of new ionotropic receptors for monoamines and other neuromodulators, which may represent novel targets for anti-parasitic drugs.