The actin cytoskeleton directly determines the morphology of the spine, and actin regulators, small GTPases such as Rac, RhoA, and CDC42, rapidly modify this cytoskeleton.
Spine of God | Neutral spine | Long spine board | Dendritic spine |
Studies have reported that filopodia may undergo more than one stage of development before becoming spines, and that clustering of certain proteins such as Drebrin may be used to identify the maturity of filopodia.