Inflammatory pain persisting for four weeks may alter exploratory behavior and passive coping strategy, when testing order is reversed. White-filled data points in the REC group indicate where REC n<4 and was not compared to SAL and CFA in ordinary one-way ANOVAs or Kruskall-Wallis tests. White-filled data points in the SAL group indicate mouse with a putative paw lesion. Lines compare SAL vs. CFA, and SAL vs. REC, line ending in a bracket compares SAL vs. CFA+REC together.
A: Schematic of experimental design.
B: Paw withdrawal thresholds in the Hargreaves assay for thermal hyperalgesia by mice injected with CFA and sustaining thermal hyperalgesia for four weeks (n=17), compared with mice injected with CFA which recovered (n=7), and with mice injected with saline (n=23).
C: Entries into the center of the OFT by mice injected with CFA and sustaining thermal hyperalgesia for four weeks (n=17), compared with mice injected with CFA which recovered (n=7), and with mice injected with saline (n=23).
D: Time spent in the center of the OFT by mice injected with CFA and sustaining thermal hyperalgesia for four weeks (n=17), compared with mice injected with CFA which recovered (n=7), and with mice injected with saline (n=23).
E: Distance traveled in the open field by mice injected with CFA and sustaining thermal hyperalgesia for four weeks (n=17), compared with mice injected with CFA which recovered (n=7), and with mice injected with saline (n=23).
F: Time spent immobile in the FST by mice injected with CFA and sustaining thermal hyperalgesia for four weeks (n=11), compared with mice injected with CFA which recovered (n=1), and with mice injected with saline (n=12).
G: Latency to immobility in the FST by mice injected with CFA and sustaining thermal hyperalgesia for four weeks (n=11), compared with mice injected with CFA which recovered (n=1), and with mice injected with saline (n=12).
H: Entries into the open arms of the EZM by mice injected with CFA and sustaining thermal hyperalgesia for four weeks (n=6), compared with mice injected with CFA which recovered (n=6), and with mice injected with saline (n=10).
I: Time spent in the open arms of the EZM by mice injected with CFA and sustaining thermal hyperalgesia for four weeks (n=6), compared with mice injected with CFA which recovered (n=6), and with mice injected with saline (n=10).