Brain Caveolin-1 Protein Expression In Rats Of Different Ages And Its Relationship With Learning And Memory

Caveolae are about 50-100 nm imaginations of the plasma membrane that contains abundant cholesterol and sphingplipid. Caveolin-1(Cav-1), a 22 kDa integral membrane protein, is a principal component of caveolae membrane, and is implicated in cholesterol trafficking, and signaling transduction. Recently, it has been reported that Cav-1 was located over the entire hippocampus neuronal surfaces; high level of Cav-1 expression was also focally enriched on growth cones. It suggested that Cav-1 may be involved in the synaptic plasticity.Learning can enhance synaptic plasticity. Other reported that some kinds of proteins may be related to the process of learning and memory, such as growth-associated protein GAP-43 and synaptophysin(Syn), which modulate synaptic plasticity.In order to find the expression profile of Cav-1 in different aged rat brains, we examined Cav-1 expression in different brain areas of different aged rats with conventional Western blot technique. The results showed that Cav-1 expression in the adult hippocampus was greater than those of the other two aged hippocampuses; among the three aged cortexes, the higher expression of Cav-1 was in the young cortex, while lower in the adult cortex; however, there were no marked differences in the Cav-1 expression among the three cerebellums. Among the three brain areas of the adult rat, higher Cav-1 level was in the cerebellum, while lower in the hippocampus and prefrontal cortex. These results suggested that Cav-1 expression may be involved in the hippocampus-dependent learning and memory.To further investigate the role of caveolin-1 in learning and memory, Cav-1 protein and other proteins were examined in the adult hippocampus, prefrontal cortex and cerebellum with Western blot after the male adult SD rats were trained for 3 days with Y-maze. The result showed that Y-maze training significantly increased Cav-1 protein level in the adult prefrontal cortex and hippocampus. It suggested that Cav-1 expression may be associated with discrimination learning and memory.Alzheimer's disease (AD) is the most common neurodegenerative disorder of the older, and is characterized clinically by progressive memory loss. Others reported that Liuwei Dihuang Wan (LW) could improve learning and memory ability during AD. Catalpol, a cycloalkene ether terpenoid, is one of the main components of LW.