PT  - JOURNAL ARTICLE
AU  - Ueda, Yoshibumi
AU  - Hayashi, Yasunori
TI  - PIP<sub>3</sub> Regulates Spinule Formation in Dendritic Spines during Structural Long-Term Potentiation
AID  - 10.1523/JNEUROSCI.3122-12.2013
DP  - 2013 Jul 03
TA  - The Journal of Neuroscience
PG  - 11040--11047
VI  - 33
IP  - 27
4099  - http://www.jneurosci.org/content/33/27/11040.short
4100  - http://www.jneurosci.org/content/33/27/11040.full
SO  - J. Neurosci.2013 Jul 03; 33
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.