Overactive bladders

This posting is not really about twitchy aging bladders that can't hold their own against a simple cup of coffee without whining uncomfortably for attention, but rather about the effect those frequent signals to head for the head have on our already addled brains.

Here's how the bladder connects with brain. That 'gotta' go now' message is sent to Barrington's nucleus, the brain center in charge of bladder contraction and urination. But no simple reflex here; rather than just send back a simple command to let 'er rip or hold on a moment dear, Barrington's nucleus feels compelled to tell the locus ceruleus all about it. This is the area in our noggin in charge of arousal and attention. I guess it makes sense because someone's got get up, find the loo, and transport the bladder there to do its business.

So researchers in Pennsylvania asked a group of rats to participate in an experiment wherein their bladder outlets were surgically narrowed to mimic an obstructed or overactive bladder(1). While Barrington's nucleus showed decreasing activity in the obstructed rodents compared to a control group (which may explain why people with OAB leak without knowing it until it's too late), the obstructed group demonstrated a hyperactive locus ceruleus.

Because the locus ceruleus is connected to the cerebral cortex, an area in charge of thinking, mood, and memory, the Philadelphia investigators conjectured that this hyped up bladder thing ultimately could affect behavior in an adverse sort of way. Indeed, the poor blocked-up rats brain activity consistent with chronic hyperarousal as seen in persons feeling anxious or stressed. And when the rats with obstructed bladders slept, their brain activity showed theta waves associated with restless sleep.

Researchers concluded: "Overactive bladder as a result of partial obstruction is particularly prevalent in the elderly, a population that is also vulnerable to neurobehavioral deficits and sleep disturbances. The present findings suggest that this visceral dysfunction may contribute to neurobehavioral and sleep deficits in this population."

Of course, surgically obstructed male rats are one thing, and aging women with overactive bladders quite another, but OAB may be just another brick in the deteriorating wall of our aging brains.
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(1)Rickenbacher, E. et al. Impact of overactive bladder on the brain: Central sequelae of a visceral pathology. Proc Natl Acad Sci U S A. 2008 Jul 21. [Epub ahead of print]