in younger neuron 38.8±15 older neuron 38.0±8 filopodia/100µm dendrite
||Rat Rattus norvegicus
||Ziv NE, Smith SJ. Evidence for a role of dendritic filopodia in synaptogenesis and spine formation. Neuron. 1996 Jul17(1):91-102. P.95 right column top paragraphPubMed ID8755481
||Abstract:"Axo-dendritic synaptogenesis was examined in live hippocampal cell cultures using the fluorescent dyes DiO to label dendrites and FM 4-64 to label functional presynaptic boutons."
||P.95 right column top paragraph: "[Investigators] found that the cumulative densities of dendritic filopodia in the younger neurons were quite comparable to the spine densities determined for the older neurons (38.8 ± 15 filopodia/100 μm dendrite, 9–12 DIV [days in vitro] 38.0 ± 8 spines/100 μm dendrite, 20–27 DIV). [Their] 1 hr observation periods were quite short, however, in comparison to the duration of developmental synaptogenesis, so it seems safe to conclude that dendritic filopodia are formed along immature dendrites in numbers easily exceeding the numbers of dendritic spines ultimately formed in cultured hippocampal neurons."