Neuron and dendrite development are NMDA dependent. However, synapses can connect an axon to another axon or a dendrite to another dendrite. The typical apical dendrite in a rat has at least 3,000 dendritic spines. This projection can be either an axon or a dendrite. ZBP1 was shown to regulate dendritogenesis (dendrite formation) in hippocampal neurons. The apical dendrite rises from the apex of the pyramidal cell's soma. Another model studied in apical dendrite development is the rat. These spines have a thin neck connecting a bulbous protrusion to the dendrite. This indicates that neural activity is critical to new dendrite formation. The solid electrolyte prevents dendrite formation. The basal dendrite however has approximately 3 fold fewer endings per primary dendrite. The method of production is via single crystal dendrite and not via simple casting. The closer to the body the dendrite, the higher the EPSP amplitude. The length of a single dendrite is usually several hundred micrometers.