In addition to the decrease in size, the overall number of neurons in the brain, the cells that comprise the brain and central nervous system, decrease in number. (drrogerholisticvet.com)
For female mice — which had no such neurons to begin with — exposure to male urine had no effect on the types of neurons in their noses. (sciencedaily.com)
Brain rhythms arise when large groups of neurons fire together. (scientificamerican.com)