Modulation of brain stem electrical activity by visceral (urinary bladder) distension

Abstract

In 32 acute experiments in the cat a correlation between sudden changes in the bladder pressure and the electrical activity of the brain was observed. In the waking state an increasing intravesical pressure served as an alerting stimulus to the nonspecific ascending brain stem mechanisms resulting in further desynchronization of the EEG record. In contrast, hypersynchrony in the form of spindle-like activity occurred at the peak pressure or more commonly during the fall of bladder pressure. When spindle activity was present in the background record an increased intravesical pressure often triggered a spindle before arousal of the electrical pattern took place. In these instances the hypersynchrony induced during the fall of intravesical pressure was considerably enhanced. Less consistent results were obtained from distension of other hollow viscera.