Phosphatidylinositol-3-kinase and protein kinase C are involved in the pro-cognitive and anti-anxiety effects of phytohormone abscisic acid in rats

The phytohormone abscisic acid (ABA) exists in animal tissues particularly in the brain. However, the neurophysiological effects of ABA have not yet been fully determined. Signaling molecules such as PKC and PI3K have been implicated in anxiety-like behavior as well as learning and memory processes. Recently, it has been demonstrated that PKC and PI3K signaling pathways participate in some biological effects of ABA. This study was designed to evaluate the effects of central injection of ABA on spatial learning and memory and anxiety-like behavior and determine its possible signaling mechanisms. Spatial learning and memory and anxiety-like behaviors were determined using Morris water maze (MWM) and plus maze tests, respectively. ABA alone or in accompanied with selective inhibitors of PKC (chelerythrine) and PI3K (LY2940029) was injected bilaterally into the cerebral lateral ventricles. The results indicated that ABA (10 mu g/rat) significantly improved rats' performance in MWM which was blocked by PKC or PI3K inhibitors. In addition, ABA showed anti-anxiety effect in plus maze test, which was not observed in PKC or PI3K inhibitor-treated rats. Overall, the results indicated that ABA has positive effect on spatial learning and memory performance and elicits anti-anxiety effects which are performed, at least in part, through PI3K/PKC signaling pathway.