A three-dimensional memory array may include a first memory array and a second memory array, stacked above the first. Some memory cells of the first array may be coupled to a first layer selector transistor, while some memory cells of the second array may be coupled to a second layer selector transistor. The first and second layer selector transistor may be coupled to one another and to a peripheral circuit that controls operation of the first and/or second memory arrays. A different layer selector transistor may be used for each row of memory cells of a given memory array and/or for each column of memory cells of a given memory array. Such designs may allow increasing density of memory cells in a memory array having a given footprint area, or, conversely, reducing the footprint area of the memory array with a given memory cell density.