Fig. 6

Hypothesized model summarizing results. After eye opening, L2/3 neurons experience an increase in dendritic spine densities. This period of spinogenesis may first require a weakening of synaptic adhesion at existing synapses. In this model, the over-stabilization of existing spines prevents new spine formation, while reduced synaptic adhesion facilitates new spine formation. It is further possible a similar but opposing mechanism facilitates pruning between P21 and P35; the strengthening of select spines by increased cell-adhesion facilitates the removal of neighboring weak spines. As a component of synaptic PAJs, nectin-3 may facilitate both the accumulation and removal of adhesion molecules at synaptic sites, perhaps through its association with afadin (created with BioRender.com)