IMAGE: Under the microscope, staining highlights a network of vasculature amid the ball of neurons that make up a minibrain. view more PROVIDENCE, R.I. [Brown University] — Scientists have recently made a wondrous variety of mini-brains — 3-D cultures of neural cells that model basic properties of living brains — but a new finding could add to the field’s growing excitement in an entirely new “vein”: Brown University’s mini-brains now grow blood vessels, too.