A three-dimensional brain tissue structure created by culturing pluripotent stem cells or similar cells. Pluripotent stem cells possess self-renewal capability and the ability to differentiate into all body cell types. ES cells (derived from the inner cell mass of a blastocyst 5–7 days post-fertilization) require a donated fertilized egg, whereas iPS cells (produced by introducing multiple genes into somatic cells like blood or skin) require donated blood or skin cells.