||Ziv NE, Smith SJ. Evidence for a role of dendritic filopodia in synaptogenesis and spine formation. Neuron. 1996 Jul17(1):91-102. P.91 left column 3rd paragraphPubMed ID8755481
||K.M. Harris, S.B. Kater Dendritic spines: cellular specializations imparting both stability and flexibility to synaptic function Annu. Rev. Neurosci, 17 (1994), pp. 341–371PubMed ID8210179
||P.91 left column 3rd paragraph:"More than 90% of excitatory axo-dendritic synapses in the CNS occur on dendritic spines (primary source). Of these, many are formed between spines and varicosities along axons en passant. This morphological arrangement has suggested that one fundamental function of the dendritic spine is to bridge physical gaps between densely packed arrays of dendrites and en passant axons (Swindale 1981)." Primary source p.341 top line:"Dendritic spines, the tiny protrusions that stud the surface of many neurons, are the location of over 90% of all excitatory synapses that occur in the CNS."