Figure 4.

Effects of intrathecal administration of the α₂-adrenoceptor antagonist yohimbine on the analgesic effects of GDNF. Yohimbine or saline was intrathecally administered on day 10 in CCI rats after three GDNF injections. Mechanical allodynia and thermal hyperalgesia were assessed on the ipsilateral hind paw 20 min after the yohimbine injection. **P < 0.01, ***P < 0.001; compared with saline treatment. Paw withdrawal threshold was evaluated using the Mann–Whitney U-test with Bonferroni correction, while latency was assessed using the unpaired t-test with Bonferroni correction; n = 7–8.