Brownian motion has applications to both brain imaging and neuroscience. One of the most mathematically elaborate forms of brain imaging is the use of q-ball imaging (QBI) diffusion magnetic resonance imaging (MRI) to the obtaining of the location and physiological health of the white matter connections in a living human brain. This talk will describe the mathematics behind QBI with examples of the kind of results that are obtained. The process of counting in humans is represented by a Brownian motion, and this example of the use of Brownian motion in neuroscience will end the talk. After the talk, there will be a discussion about possible future relations between neuroscience and mathematics.