From bladder to brain: How you know when it's time to go.

The decision to urinate relies on assessing bladder fullness and context to determine an appropriate time and place to go. Any disruption in this interoceptive process results in frequent and sometimes debilitating consequences in daily life. Recent work has uncovered key pathways and brain regions that contribute to the sense of bladder stretch and the control of urinary reflexes, but many open questions remain. Here, we review the known mechanisms that convey sensory information from the bladder to the brain and back down again, and we highlight the knowledge gaps and opportunities for better understanding this system, which will be critical to develop effective therapies for urinary dysfunction.