Experts at the Children's Hospital of
Philadelphia in Pennsylvania say that the results, if they turn out to be true
in humans too, may explain the disrupted sleep, reduced ability to concentrate
and confusion that often accompany ageing.
"If you have an overactive bladder,
you don't just have a bladder problem. It has neurobehavioural
consequences," New Scientist magazine quoted neurologist Rita Valentino as
During the study, the researchers conducted
surgeries on rats to provide them overactive bladders.
When the animals' brains were scanned, the
researchers found increased activation of a region of the brainstem called the
locus coeruleus, which helps control alertness.
Valentino points out that this region is
activated only when the bladder is full in normal mammals, and helps them to
disengage from other activities.
However, in rats with overactive bladders,
she and her colleagues found that activation to occur continually.
The researchers said that an overactive
locus coeruleus triggered increased and disordered activity in the forebrain
that controls higher brain function, something that may lead to anxiety,
disrupted sleep and other behavioural problems in humans.
This is the first time that a study has
shown that a bladder disorder can have a direct effect on brain function.
"This helps complete the puzzle of why
overactive bladder symptoms are so disruptive to quality of life," said
Craig Comiter, a urologist at Stanford University School of Medicine in California.
Valentino says that bowel disorders like
irritable bowel syndrome may also overactivate the locus coeruleus, and that
this may help better understand psychiatric disorders that often accompany IBS.