Melatonin, Learning, memory and Alzheimer's - Wikipedia
Melatonin receptors appear to be important in mechanisms of learning and memory in mice,[81] and melatonin can alter electrophysiological processes associated with memory, such as long-term potentiation (LTP). The first published evidence that melatonin may be useful in Alzheimer's disease was the demonstration that this neurohormone prevents neuronal death caused by exposure to the amyloid beta protein, a neurotoxic substance that accumulates in the brains of patients with the disorder.[82] Melatonin also inhibits the aggregation of the amyloid beta protein into neurotoxic microaggregates that, it seems, underlie the neurotoxicity of this protein, causing death of neurons and formation of neurofibrillary tangles, the other neuropathological landmark of Alzheimer's disease.[83]
Melatonin has been shown to prevent the hyperphosphorylation of the tau protein in rats. Hyperphosphorylation of tau protein can also result in the formation of neurofibrillary tangles. Studies in rats suggest that melatonin may be effective for treating Alzheimer's disease.[84] These same neurofibrillary tangles can be found in the hypothalamus in patients with Alzheimer's, adversely affecting their bodies' production of melatonin. Another study has implicated heightened afternoon agitation found in many Alzheimer's patients, called sundowning, with a phase delay in core body temperature.[85] This may suggest a possible connection to melatonin production.
