Quantitative profiling of DOR immunofluorescence at the plasma membrane and in the cytoplasm of primary sensory neurons in the mouse spared nerve injury model of neuropathic pain
| Authors | |
|---|---|
| Year of publication | 2025 |
| Type | Appeared in Conference without Proceedings |
| Citation | |
| Description | Delta opioid receptor (DOR) plays a crucial role in pain perception. Under physiological conditions, its intraneuronal localization predominates over its presence at the plasma membrane of primary sensory neurons (PSNs) in the dorsal root ganglia (DRG). However, the regulation of DOR intraneuronal trafficking remains controversial across different models of neuropathic pain. We compared the quantitative profiling of DOR immunofluorescence (IF) at the plasma membrane and in the cytoplasm of DRG neurons in the naive and sham-operated mice, and mice subjected to unilateral spared nerve injury (SNIt) of the sciatic nerve at 7- and 21-days post-operation (POD7, POD21). Cryostat sections of L3 DRG from both the ipsilateral and contralateral sides were immunostained for DOR. The intensity profiles of DOR-IF were analyzed across individual somata of large, medium and small DRG neurons. In Sham POD7 group, the DOR-IF intensity was significantly reduced bilaterally in the cytoplasm of all subtypes of DRG neurons compared to the naive control group, while same reduction on the plasma membrane was observed exclusively in ipsilateral DRG neurons. In contrast, SNIt POD7 compared to the sham group induced an increase in DOR-IF on the plasma membrane and in the cytoplasm especially in large DRG neurons. Comparing SNIt POD7 to naive, there was predominantly decrease in DOR-IF bilaterally. At POD21, both Sham and SNIt surgeries induced an increase in DOR-IF located to the plasma membrane of large DRG neurons in ipsilateral side. Cytoplasmic levels in large neurons, as well as both cytoplasmic and plasma membrane levels in medium and small neurons, were either nearly equal to those in naive group (in sham-operated mice) or predominantly reduced bilaterally (in the SNIt-group). These results indicate that DOR trafficking is a dynamic and nerve injury-responsive process that changes over time among DRG neuronal subpopulations. |
| Related projects: |