Respiratory motor nerve activities during spontaneous bladder contractions

Area of Science:

• Neuroscience
• Physiology
• Urology

Background:

• Spontaneous bladder contractions (SBCs) are a key aspect of bladder function.
• The neural control of SBCs involves complex interactions with other physiological systems.
• Previous research has not fully elucidated the respiratory and airway responses during SBCs.

Purpose of the Study:

• To investigate the effects of SBCs on respiratory motor nerve activity.
• To determine the impact of SBCs on upper airway nerve function.
• To explore the neural pathways involved in the respiratory response to bladder activity.

Main Methods:

• Monitoring spontaneous bladder contractions (SBCs) in decerebrate, vagotomized, paralyzed, ventilated cats.
• Recording intravesical pressure and respiratory motor nerve activities (phrenic, hypoglossal, facial, laryngeal, triangularis sterni, iliohypogastric nerves).
• Assessing the effects of passive bladder distension and pelvic nerve section on nerve activities.

Main Results:

• SBCs significantly reduced phrenic, hypoglossal, and laryngeal nerve activity, with hypoglossal activity often disappearing.
• Triangularis sterni nerve showed an initial decrease followed by an increase, while iliohypogastric nerve activity increased during SBCs.
• Bladder distension mimicked these changes, which were abolished by pelvic nerve section, indicating a reflex pathway.

Conclusions:

• SBCs elicit a coordinated respiratory response involving changes in multiple respiratory and airway nerves.
• Reflexes originating from the urinary bladder can influence respiratory motor output and upper airway muscle tone.
• These bladder-induced reflexes may potentially compromise upper airway patency under certain physiological conditions.