MTNR1A and Alzheimer disease: To date, membrane (MT1 and MT2) and nuclear (retinoid Z receptor/retinoid-related receptor) receptors, as well as receptor-independent modalities, have been identified for melatonin.35 Although few differences were identified in MT1 and MT2 receptors between WT and APP/PS1 mouse hearts, the nonselective melatonin membrane receptor blocker luzindole nullified melatonin-mediated cardioprotection against APP/PS1 mutant AD pathology, indicating a membrane receptor-dependent mechanism for melatonin.