Virus-labeled bladder neurons and cholinergic neurons in the L6-S1 IML three days after infecting the bladder A: Virus labeled neurons in IML. B: Cholinergic neurons in IML. Three of the neurons in A (arrows) are also cholinergic (arrows in B) and are therefore preganglionic neurons that innervate bladder-designated postganglionic neurons in the major pelvic ganglion. Also in A are neurons that are labeled by bladder virus that are not cholinergic. These are interneurons. There are cholinergic neurons in B: that are not bladder neurons. These innervate other visceral organs (e.g. colon). Up is dorsal and left is medial. LF: lateral funiculus. Bar: 200 microns.