Identification of brain structures involved in micturition with functional magnetic resonance imaging (fMRI).
OBJECTIVE
The voluntary control of micturition is believed to be integrated by complex interactions among the brainstem, subcortical areas and cortical areas. Several brain imaging studies using positron emission tomography (PET) have demonstrated that frontal brain areas, the limbic system, the pons and the premotor cortical areas were involved. However, the cortical and subcortical brain areas have not yet been precisely identified and their exact function is not yet completely understood.


METHODS
This study used functional magnetic resonance imaging (fMRI) to compare brain activity during passive filling and emptying of the bladder. A cathetherism of the bladder was performed in seven healthy subjects (one man and six right-handed women). During scanning, the bladder was alternatively filled and emptied at a constant rate with bladder rincing solution.


RESULTS
Comparison between passive filling of the bladder and emptying of the bladder showed an increased brain activity in the right inferior frontal gyrus, cerebellum, symmetrically in the operculum and mesial frontal. Subcortical areas were not evaluated.


CONCLUSIONS
Our results suggest that several cortical brain areas are involved in the regulation of micturition.
Hruz
P
P
Department of gastroenterology, UCSD School of medicine, 9500 Gilman Drive, UC 303, 92093 La Jolla, USA.
Lövblad
K O
KO
Nirkko
A C
AC
Thoeny
H
H
El-Koussy
M
M
Danuser
H
H
D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012016:Reference Values; D015203:Reproducibility of Results; D001743:Urinary Bladder / Q000502:physiology; D014554:Urination / Q000502:physiology*