RT Journal Article SR Electronic T1 PIP3 Regulates Spinule Formation in Dendritic Spines during Structural Long-Term Potentiation JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 11040 OP 11047 DO 10.1523/JNEUROSCI.3122-12.2013 VO 33 IS 27 A1 Ueda, Yoshibumi A1 Hayashi, Yasunori YR 2013 UL http://www.jneurosci.org/content/33/27/11040.abstract AB Dendritic spines are small, highly motile structures on dendritic shafts that provide flexibility to neuronal networks. Spinules are small protrusions that project from spines. The number and the length of spinules increase in response to activity including theta burst stimulation and glutamate application. However, what function spinules exert and how their formation is regulated still remains unclear. Phosphatidylinositol-3,4,5-trisphosphate (PIP3) plays important roles in cell motility such as filopodia and lamellipodia by recruiting downstream proteins such as Akt and WAVE to the membrane, respectively. Here we reveal that PIP3 regulates spinule formation during structural long-term potentiation (sLTP) of single spines in CA1 pyramidal neurons of hippocampal slices from rats. Since the local distribution of PIP3 is important to exert its functions, the subcellular distribution of PIP3 was investigated using a fluorescence lifetime-based PIP3 probe. PIP3 accumulates to a greater extent in spines than in dendritic shafts, which is regulated by the subcellular activity pattern of proteins that produce and degrade PIP3. Subspine imaging revealed that when sLTP was induced in a single spine, PIP3 accumulates in the spinule whereas PIP3 concentration in the spine decreased.