Figures & data
Figure 1. (A) Schematic of DD synapse remodeling. In L1 worms (Left) DD neurons form synapses (green circles) along the ventral neurites and receive cholinergic synaptic inputs (blue) in their dorsal neurites through the ACh receptor (blue diamonds). After DD remodeling in L2 and older animals (right), synapses along the ventral neurite are eliminated, and new synapses are formed with dorsal muscles. The VD neurons now synapse onto the ventral muscles and receive cholinergic synaptic input in ther dorsal neurites. DD neurons now receive cholinergic synaptic input in their ventral neurites (blue). (B) The mechanics of DD remodeling (1) A transcriptional program involving UNC-30, LIN-14, IRX-1 and HBL-1 modulates synapse remodeling in DD neurons, to regulate the expression of factors that promote (green) and inhibit (red) DD remodeling. (2) Ventral synapse elimination requires Cyclin-1/CYY-1 and components of the cell death pathway, including CED-3. (3) Activation of DLK-1 results in an increase in dynamic MTs through the activation of MT catastrophe factors like KLP-7 and SPAS-1. (4) Increased dynamic MTs facilitate UNC-116 mediated synaptic vesicle transport, and CDK-5 stimulates UNC-104 mediated synaptic vesicle transport to the dorsal neurite. (5) Patterning of newly formed synapses is achieved through coordinated activity of UNC-104 and DHC-1.
