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Acute Intermittent Hypoxia‐Induced Plasticity: What About Micturition?
Author(s) -
Collins William F,
Catege Marianna,
Solomon Irene C
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.986.2
Subject(s) - medicine , urination , reflex , anesthesia , hypoxia (environmental) , urinary bladder , urinary system , saline , urology , chemistry , organic chemistry , oxygen
It is well documented that acute intermittent hypoxia (AIH) induces sustained respiratory motor plasticity (long‐term facilitation) lasting more than 60 minutes. The goal of the present study is to characterize possible similar effects of AIH on lower urinary tract function. To this end, bladder intravesical pressure and external urethral sphincter (EUS) EMG activity were recorded in urethane‐anesthetized, spontaneously breathing adult female Sprague Dawley rats during continuous infusion of saline into the bladder to elicit reflex micturition events. The rate of saline infusion was adjusted to achieve a baseline bladder inter‐contraction interval (ICI) of approximately 4 minutes. Following 30–40 minutes of baseline recording, rats were exposed to a single bout of AIH consisting of three five‐minute episodes of hypoxia (10% O 2 ; 90% N 2 ) each separated by five‐minute exposures to room air. Data acquisition continued for at least 90 minutes following the AIH exposure. In addition to the classic induction of respiratory motor plasticity, changes in reflex micturition were observed during the AIH recovery period and were characterized by sustained increases in bladder ICI (i.e., decreased voiding frequency), bladder pressure threshold (i.e., elevated intravesical pressure at the onset of an active bladder contraction) and EUS activity during bladder filling (i.e., increased EUS guarding reflex) lasting up to 60 minutes post AIH. In control experiments, sustained changes in bladder ICI, bladder pressure threshold and EUS activation were not observed following a single fifteen‐minute episode of sustained hypoxia (10% O 2 ; 90% N 2 ). These data suggest that AIH‐induced neuroplasticity extends beyond respiratory motor control and includes both somatic and autonomic motor function. Support or Funding Information Support for this project was provided by The Thomas Hartman Center for Parkinson's Research at Stony Brook University and The SUNY Brain Network of Excellence.