# Enhanced BDNF and ROS in Mucosa of Lower Motor Neuron Lesioned Dog Bladder Following Somatic Motor Nerve Transfer

## TL;DR

Somatic nerve transfer in dogs with bladder nerve damage increased brain-derived neurotrophic factor (BDNF) and reactive oxygen species (ROS) in bladder mucosa, suggesting a potential role in nerve recovery.

## Contribution

The study demonstrates that somatic nerve transfer can enhance BDNF and ROS levels in damaged bladders, potentially aiding reinnervation.

## Key findings

- BDNF and ROS levels were highest in reinnervated bladders compared to controls and decentralized bladders.
- GDNF and TNF-α levels in reinnervated bladders returned to control levels after nerve transfer.
- BDNF and GDNF levels correlated with bladder function and nerve recovery metrics.

## Abstract

Neurotrophic factors and reactive oxygen species (ROS) modulate neuronal plasticity. In a model of a lower motor neuron lesioned bladder, somatic nerve transfer was used as a reinnervation strategy. Levels of neurotrophins, ROS, and TNF-α in bladder mucosa and muscle layers collected from three groups of adult female dogs: (1) Decentralized, via bilateral transection of coccygeal and sacral spinal roots, lumbar 7 dorsal roots, and hypogastric nerves, then 6–21 mo recovery; (2) reinnervated (ObNT-Reinn), after similar decentralization for 12 mo, then bilateral obturator-to-vesical nerve transfer and 8–12 mo recovery; and (3) Controls. In mucosa, BDNF and ROS levels were highest in ObNT-Reinn bladders, GDNF and TNF-α levels were restored to Control levels in ObNT-Reinn bladders (lowest in Decentralized). NT-3 and ARTN were lower in ObNT-Reinn and Decentralized bladders versus Controls. In muscle, ROS was lower in ObNT-Reinn muscle versus Controls. BDNF mucosa levels correlated with bladder axonal density and detrusor layer thickness; and GDNF mucosal correlated with bladder contraction after vesical or transferred obturator nerve electrical stimulation, as did BDNF and GDNF muscle levels. The increased BDNF and GDNF in bladders that underwent somatic nerve transfer with subsequent recovery suggest that BDNF and GDNF may help promote the reestablishment of bladder innervation.