Tau has not been reportedly detected as the LRRK2 binding protein in other studies involving proteomic analysis. Because LRRK2 appears to bind to a wide variety of proteins, including abundant proteins such as chaperones and actin-related molecules, it is possible that the relative proportion of tau among total LRRK2-associated proteins was insufficient for detection in some cases. In the present study, we focused our analysis on tau only, and detected it by Western analysis using a specific antibody. In addition, as we describe here, LRRK2 binds only to tubulinassociated tau and not to free tau, making it more difficult to be detected as a specifically LRRK2-associated molecule. Several candidate LRRK2-substrate molecules and various mechanisms of neurodegeneration caused by LRRK2 mutations have been reported, i.e., the actin-cytoskeleton-related ERM whose inappropriate phosphorylation causes perturbation of cytoskeletal organization, eukaryotic initiation factor 4E-binding protein 1 whose hyperphosphorylation induces dysregulated protein translation, and several signal transduction molecules such as TAOK3, serine/threonine kinases 3, 24, and 25, Akt1, and mitogen-activated kinase kinases Deacetyl-ganoderic-acid-F whose hypoor hyperphosphorylation leads to abnormal signal transduction that can induce a wide variety of cellular damage, including activation of the caspase cascade. With regard to microtubule-related molecules, Gillardon has identified b-tubulin as the LRRK2 substrate and reported that its increased phosphorylation by G2019S LRRK2 enhanced microtubule assembly/stability in the presence of microtubules-associated proteins. Lin et al. have reported that G2019S LRRK2transgenic Drosophila neurons exhibit GSK-3b-mediated hyperphosphorylation and mislocalization of tau. The R1441G and G2019S LRRK2 transgenic mice exhibiting abnormality in dopamine transmission reportedly have the hyperphosphorylated tau in their brain. The results obtained in the present study demonstrating that G2019S and I2020T mutant LRRK2 elicit direct hyperphosphorylation of tau may further support the notion that impairment of microtubule dynamics plays a crucial role in the neurodegeneration caused by LRRK2 mutations. In addition, LRRK2 immunoreactivity has been detected in tau-positive inclusions in samples of brain tissue affected by various neurodegenerative disorders. In particular,Lucidenic-acid-A LRRK2 is closely associated with tau-positive inclusions in FTDP-17 caused by N279K tau mutations. It is possible that the LRRK2mediated phosphorylation of tau reported here may make an important contribution to the formation of these pathological features. Subarachnoid hemorrhage is a vital clinical syndrome, nearly 80% of which is caused by the rupture of cerebral aneurysm. Approximately 10 in 100,000 people experience aneurysmal SAH every year, in which, about 40% die and 30% of the survivors suffer from morbidity. Severe cerebral vasospasm is one of the major causes of mortality and morbidity in aneurysmal SAH. Therefore, the prevention of refractory CV is always a primary concern in experimental and clinical studies. To explore the mechanisms of experimental SAH pathophysiology, various approaches were tested on animal models; however, most of these methods were histological analyses with few in vivo interpretations. The in vivo evaluative tools of CV include laser Doppler flowmetry -cerebral blood flow measurement, computed tomography angiography, magnetic resonance and digital subtraction angiography. Because of limited resolution or indirection, these methods could not be widely used to detect and evaluate CV in experimental SAH models.