Neurexin directs partner-specific synaptic connectivity in C. elegans
In neural circuits, individual neurons often make projections onto multiple postsynaptic partners.
individual neurons can direct differential patterns of connectivity with their post-synaptic partners through partner-specific utilization of synaptic organizers, offering a novel view into molecular control of divergent connectivity.
Nervous systems are complex networks of interconnected cells called neurons. These networks vary in size from a few hundred cells in worms, to tens of billions in the human brain. Within these networks, each individual neuron forms connections – called synapses – with many others. But these partner neurons are not necessarily alike. In fact, they may be different cell types. How neurons form distinct connections with different partner cells remains unclear.
Neurons often make divergent synaptic connections onto multiple postsynaptic partners, and these connections are critical for proper neural circuit performance in the brain.
distinct molecular signaling pathways act in parallel to establish divergent connections at dyadic synapses in the motor circuit, raising the interesting possibility that differential use of synaptic organizers may be similarly utilized in the brain to provide a molecular code directing divergent connectivity
cholinergic connectivity with distinct synaptic targets–muscles and GABAergic neurons–is coordinately regulated with cholinergic neuronal identity by unc-3 transcriptional control of alternate synaptic organizers.
synaptic target-specific utilization of organizers such as neurexin may specify divergent connectivity, and provide a molecular mechanism for target-specific regulation of synapse development.
Common Design 