Fig. 1.

Experimental design to conditionally silence L2–L5 interneurons in the freely behaving adult rat. a In the lumbar spinal cord, L2 neurons with ipsilateral or contralateral projections to L5 were targeted for conditional silencing. Bilateral injections of AAV2-CMV-rtTAV16 (blue triangles) and HiRet-TRE-EGFP.eTeNT (green) were performed at L2 and L5, respectively. b In the presence of doxycycline (DOX), only double-infected neurons conditionally express eTeNT (adapted from Kinoshita et al.⁹). eTeNT is transported to the terminal field where it prevents synaptic vesicle release thereby silencing neurotransmission. c Behavioral assessments were performed at four control time points (Baseline, BL; Pre-DOX1, PD1; DOX^OFF; Pre-DOX2, PD2) and during two rounds of DOX^ON silencing separated by a 1-month washout (DOX1^ON days 3, 5, 8 and DOX2^ON days 3 and 5). Illustrations by A. Pocratsky