Glial cells provide scaffolding. Cells aggregate with others of a similar kind - molecules aid in recognition. Cells adopt a preferential orientation. Most neurons generate processes only after they reach their final position. Pattern of dentritic branching may be genetically determined, but mechanical influences can modify the form of the neuron.
Growth is controlled by growth cones.
Fasciculation - tendency of neurons to grow in close association with their neighbours. Neurons compete via their functional activity. Number formed by mitosis - may be decreased by a decrease in the precursor pool. Number migrating to final location. Dendritic elaboration begins after neurons settle in their definitive locations.