TRH and Alzheimer disease: The thyroid dysfunction with elevated thyroid hormone levels appears to be associated with increased necrotic neuron death[34] and oxidative stress.[35] Also TRH analogs have been shown to increase acetylcholine synthesis and release in rodents.[36] When this exposure is sustained, acetylcholine depletion may ensure and consequently, the cognitive problems associated with the cholinergic deficit noted in AD brains.