Craniofacial nerve injury occasionally causes spread of mechanical hypersensitivity in humans. We modeled this abnormality by transecting the infraorbital nerve (IONX) in male and female mice of the 23 AXB-BXA recombinant inbred lines and their progenitor strains, comparing their responsivity to 7 applications of a 0.2 gram Von Frey filament to the ears, paws and tail. When normalizing their mechano-responsivity on postoperative days 14 and 21 by the preoperative values, subtracting data of sham-operated from IONX mice, highly contrasting line/strain-specific differences were demonstrated. Similar line/strain-specific variability in the spread of mechano-allodynia to the paws post-IONX was demonstrated in our novel 3 minute place-avoidance paradigm, assessing parameters of mobility on a smooth surface versus a pro-allodynic granular surface. These genetically-controlled, widespread changes in mechano-sensitivity caused by IONX were minimally sexually dimorphic and mapped to intervals on chromosomes 5, 9, and 13. Further analysis is needed to identify the causative genes.

Craniofacial nerve injury occasionally causes spread of mechanical hypersensitivity in humans. We modeled this abnormality by transecting the infraorbital nerve (IONX) in male and female mice of the 23 AXB-BXA recombinant inbred lines and their progenitor strains, comparing their responsivity to 7 applications of a 0.2 gram Von Frey filament to the ears, paws and tail. When normalizing their mechano-responsivity on postoperative days 14 and 21 by the preoperative values, subtracting data of sham-operated from IONX mice, highly contrasting line/strain-specific differences were demonstrated. Similar line/strain-specific variability in the spread of mechano-allodynia to the paws post-IONX was demonstrated in our novel 3 minute place-avoidance paradigm, assessing parameters of mobility on a smooth surface versus a pro-allodynic granular surface. These genetically-controlled, widespread changes in mechano-sensitivity caused by IONX were minimally sexually dimorphic and mapped to intervals on chromosomes 5, 9, and 13. Further analysis is needed to identify the causative genes.