kenyon cells are the intrinsic neurons of the mushroom body, a neuropil found in the brains of most arthropods and some annelids. they were first described by f. c. kenyon in 1896. the number of kenyon cells in an organism varies greatly between species. for example, in the fruit fly, "drosophila melanogaster," there are about 2,500 kenyon cells per mushroom body, while in cockroaches there are about 230,000.