A 3D Atlas of Visceral and Somatic Pelvic Motor Neurons in Whole Mounts of Female and Male Rat Spinal Cords

Abstract

The sexually dimorphic genitourinary organs and specialized striated muscles in the pelvis are controlled by a spinal cord motor neuron (MN) subsystem that produces reflexogenic and psychogenic (conscious) visceral and somatic motor activity during urinary continence and voiding, scent marking (in some species), defecation, reproduction, and sexual activity. To produce a three-dimensional (3D) atlas of the pelvic MN system, we performed whole-mount immunostaining and advanced 3D microscopy on the caudal spinal cord of adult female and male rats. We used choline acetyltransferase immunolabeling to study the macroscopic topology of visceral (autonomic preganglionic; VMN) and somatic MN (SMN) s..