alpha-Tocopherol affects neuronal plasticity in adult rat dentate gyrus: the possible role of PKCdelta.

Hippocampus dentate gyrus (DG) is characterized by neuronal plasticity processes in adulthood, and polysialylation of NCAM promotes neuronal plasticity. In previous investigations we found that alpha-tocopherol increased the PSA-NCAM-positive granule cell number in adult rat DG, suggesting that alpha-tocopherol may enhance neuronal plasticity. To verify this hypothesis, in the present study, structural remodeling in adult rat DG was investigated under alpha-tocopherol supplementation conditions. PSA-NCAM expression was evaluated by Western blotting, evaluation of PSA-NCAM-positive granule cell density, and morphometric analysis of PSA-NCAM-positive processes. In addition, the optical density of synaptophysin immunoreactivity and the synaptic profile density, examined by electron microscopy, were evaluated. Moreover, considering that PSA-NCAM expression has been found to be related to PKCdelta activity and alpha-tocopherol has been shown to inhibit PKC activity in vitro, Western blotting and immunohistochemistry followed by densitometry were used to analyze PKC. Our results demonstrated that an increase in PSA-NCAM expression and optical density of DG molecular layer synaptophysin immunoreactivity occurred in alpha-tocopherol-treated rats. Electron microscopy analysis showed that the increase in synaptophysin expression was related to an increase in synaptic profile density. In addition, Western blotting revealed a decrease in phospho-PKC Pan and phospho-PKCdelta, demonstrating that alpha-tocopherol is also able to inhibit PKC activity in vivo. Likewise, immunoreactivity for the active form of PKCdelta was lower in alpha-tocopherol-treated rats than in controls, while no changes were found in PKCdelta expression. These results demonstrate that alpha-tocopherol is an exogenous factor affecting neuronal plasticity in adult rat DG, possibly through PKCdelta inhibition.

Ferri P ，Cecchini T ，Ambrogini P ，Betti M ，Cuppini R ，Del Grande P ，Ciaroni S ... -  《journal of neurobiology》

Remodeling of neuronal circuitries in human temporal lobe epilepsy: increased expression of highly polysialylated neural cell adhesion molecule in the hippocampus and the entorhinal cortex.

Mikkonen M ，Soininen H ，Kälviänen R ，Tapiola T ，Ylinen A ，Vapalahti M ，Paljärvi L ，Pitkänen A ... -  《ANNALS OF NEUROLOGY》

Dopamine acting through D2 receptors modulates the expression of PSA-NCAM, a molecule related to neuronal structural plasticity, in the medial prefrontal cortex of adult rats.

Castillo-Gómez E ，Gómez-Climent MA ，Varea E ，Guirado R ，Blasco-Ibáñez JM ，Crespo C ，Martínez-Guijarro FJ ，Nácher J ... -  《-》

Curcumin-induced degradation of PKC delta is associated with enhanced dentate NCAM PSA expression and spatial learning in adult and aged Wistar rats.

Conboy L ，Foley AG ，O'Boyle NM ，Lawlor M ，Gallagher HC ，Murphy KJ ，Regan CM ... -  《-》

PSA-NCAM expression in the rat medial prefrontal cortex.

Varea E ，Nácher J ，Blasco-Ibáñez JM ，Gómez-Climent MA ，Castillo-Gómez E ，Crespo C ，Martínez-Guijarro FJ ... -  《NEUROSCIENCE》