MAPT and Alzheimer disease: A set of 30 inhibitory compounds with concentration-response profiles in which the second and third highest tested doses (i.e., 6.7 and 2.2 μM) were relatively well separated from markers of neurotoxicity were tested at 0.24, 2.2, and 6.7 μM in primary rat cortical cultures plated in 96-well plates, with compound addition at DIV7 in the absence of AD-tau seeding.