“…A more likely scenario, however, is that exercise is modulating APP metabolism directly (for review, see Turner et al, 2003) by increases in neuronal activity (Lee et al, 2003). For example, APP processing can be augmented by PKC, MAPK (mitogen-activated protein kinase), and phospholipase C (for review, see Turner et al, 2003), and these pathways are known to be activated by exercise (Shen et al, 2001;Molteni et al, 2002;our unpublished observations). In support of the neuronal activity hypothesis, it has also been shown that M 1 muscarinic agonist treatment decreases A load in a triple transgenic model of AD (Caccamo et al, 2004), consistent with existing reports (for review, see Rossner et al, 1998).…”