Figure 1.

Kinase pathways mediate dendritic morphogenesis and maturation. (A) Immature dendritic neurites undergo expansive growth and branching during early development. The PI3K-Akt-mTor kinase and Hippo pathway are critical for growth. Activity dependent growth is primarily mediated by Ca⁺² influx and downstream signaling by CaMK family members. (B) During arborization, dendrites of the same neuron avoid overlap through a principle known as self-avoidance, while neighboring neurons of the same type grow in well-defined territories. Kinases that mediate self-avoidance and dendritic tiling have been identified through screens in Drosophila peripheral sensory da neurons. (C) Most excitatory neurons on maturation form actin rich protrusions called dendritic spines that serve as sites of synapse formation. Several kinases that regulate the synaptic cytoskeleton are important regulators of spine formation in hippocampal and cortical neurons. (D) Calcium influx through N-methyl D-aspartate (NMDA) receptors and voltage gated calcium channels (VGCC) activate CaMK kinases, which mediate spine morphogenesis and plasticity. Mutations in several kinases important for dendritic spine formation are associated with neuropsychiatric diseases.