THE CENTRAL-NERVOUS-SYSTEM CONTROL OF MICTURITION IN CATS AND HUMANS

Recent findings concerning the central control of micturition in cats are compared to findings obtained from dynamic imaging studies in huma ns. In the cat, three areas in the brainstem and diencephalon are spec ifically implicated in the control of micturition: (1) Barrington's nu cleus or the pontine micturition center in the dorsomedial pontine teg mentum directly excites bladder motoneurons and indirectly inhibits, v ia inhibitory interneurons in the medial sacral cord, urethral sphinct er motoneurons; (2) the periaqueductal grey receiving bladder filling information; and (3) the pre-optic area of the hypothalamus possibly i nvolved in determining the beginning of micturition. According to PET- scan studies, in humans the same supraspinal regions are active during micturition. In the cat another area, located in the ventrolateral po ntine tegmentum and is called the L-region, which controls the motoneu rons of the pelvic floor, including the external urethral sphincter. T his region might be considered as the pontine storage center. In human s the L-region is especially active in volunteers who tried but did no t succeed to micturate. The results suggest that in cats and humans at the brainstem and diencephalic levels micturition is organized in the same way. (C) 1998 Elsevier Science B.V. All rights reserved.