Re-established Micturition Reflexes Show Differential Activation Patterns after Lumbosacral Ventral Root Avulsion Injury and Repair in Rats

This study investigates the mechanisms behind incomplete bladder function recovery after a specific spinal cord injury and repair procedure in rats. The procedure involves reimplanting damaged nerve roots into the spinal cord to restore bladder control. The researchers analyzed bladder activity and muscle activity around the urethra to understand why the rats couldn't completely empty their bladders, even after the surgery appeared to restore some nerve function. The findings suggest that the incomplete recovery is due to a shortened bladder contraction phase, reduced muscle activity in the urethra, and a lack of coordination between bladder contraction and urethral muscle activity.

• 1
  The implanted series showed reflex bladder contractions with a significantly shortened urine expulsion phase compared to sham-operated controls.
• 2
  The implanted series exhibited markedly decreased phasic EUS EMG activity during micturition compared to controls.
• 3
  The implanted series demonstrated a pronounced bladder-sphincter dys-coordination, indicated by a significantly delayed onset of the switch from tonic to phasic/large-amplitude tonic EUS EMG activity during the urine expulsion phase.