Functional imaging and the central control of the bladder

The central control of the bladder is a complex, multilevel process. Recent advances in functional brain imaging have allowed research into this control in humans. This article reviews the functional imaging studies published to date and discusses the regions of the brain that have been implicated in the central control of continence. Brain regions that have been implicated include the pons (pontine micturition center, PMC), periaqueductal gray (PAG), thalamus, insula, anterior cingulate gyrus, and prefrontal cortices. The PMC and the PAG are thought to be key in the supraspinal control of continence and micturition. Higher centers such as the insula, anterior cingulate gyrus, and prefrontal regions are probably involved in the modulation of this control and cognition of bladder sensations, and in the case of the insula and anterior cingulate, modulation of autonomic function. Further work should aim to examine how the regions interact to achieve urinary continence.