Pronounced attenuation of thermal sensitivity in mid-plantar and distal locations after mid-plantar injection of MRS1477 + capsaicin. Thermal sensitivity was mapped across the plantar surface of rat hind paws with the small-diameter Aδ laser stimulus. Withdrawal response scores were determined by subjective scoring on a 0 to 4 scale (see Methods). Nocifensive responses were significantly attenuated by treatment with 2 μg MRS1477 + 30 μg CAP as compared to untreated paws in the mid-plantar region and distally in the toes, but not in the heel. Testing was performed 48 h after injection using a laser stimulus intensity of 4.12 W/mm2. The beam diameter (1.6 mm) is shown to scale. ■2 μg MRS1477 + 30 μg CAP (n = 3). □Contralateral - No Tx (n = 3).
Lebovitz et al. Molecular Pain 2012 8:70 doi:10.1186/1744-8069-8-70