EE has been demonstrated to induce beneficial cognitive effects in genetically targeted mouse models of AD [58–64]. The effects of EE on amyloid plaque formation/clearance Roscovitine cost have been found to differ widely in different studies [58,59,65]. However, as amyloid plaques (and neurofibrillary tangles) are primarily assessed as neuropathological markers, and a range of other molecular and cellular changes have been implicated in AD pathogenesis, an
understanding of the mechanisms mediating the beneficial effects of EE is likely to be found elsewhere. Other aspects of EE-induced benefits in AD mouse models have been addressed, including the issue of timing with respect to preventative and therapeutic effects [66,67]. The EE studies in AD mice have been extended to a range of different molecular, cellular and behavioural effects [67–73]. A recent study has implicated β2 adrenergic receptors in the beneficial effects of EE on hippocampal synaptic plasticity in AD mice . One important aspect of the cognitive enhancing effects of EE is that these
have also been reported in wild-type rodents . Thus, many of the cognitive enhancing effects of EE observed in animal models of AD may largely reflect a wild-type effect superimposed on an AD genotype. With this in mind, it is important to contemplate the kinds of changes that are induced at molecular and cellular screening assay levels by EE in wild-type rodents, and this will be discussed below. Increased physical exercise alone have been shown to have beneficial effects in AD mice [60,75–78], although a late exercise intervention in one transgenic AD mouse model did not exert cognitive enhancement . However, cognitive stimulation
has also been found to constitute a major component of the beneficial effects of EE in AD mice [60,80]. This is Decitabine datasheet consistent with epidemiological and interventional clinical studies suggesting that enhanced cognitive stimulation and physical exercise may delay onset and possibly also slow progression of AD and other forms of dementia [81–84]. EE has also been demonstrated to induce beneficial effects in animal models of Parkinson’s disease (PD). PD is a neurodegenerative disease involving symptoms including tremor, rigidity, slowness of movement and gait problems, and can be associated with additional cognitive and psychiatric features. A key neuropathological hallmark is loss of dopaminergic neurones, particularly in the substantia nigra (SN). As for AD, the familial early-onset form of PD is less common, compared to sporadic late-onset PD, which constitutes the vast majority of cases. Another parallel with AD is that the genetics of familial PD is far better understood than the common sporadic form of the disease.