Fig. 1

Time-dependent changes in basal paw withdrawal responses in male rats to mechanical, heat, and cold stimuli after immobilization 6 h daily for consecutive days. a, b Mechanical stimuli. c, d Heat stimuli. e Cold stimuli. a, c, e Responses of left paws. b, d Responses of right paws. Significant reductions were seen in bilateral paw withdrawal thresholds in response to mechanical stimulation on day 5 post-immobilization (a, b), in bilateral paw withdrawal latencies in response to heat stimulation on day 4 and 5 post-immobilization (c, d), and in paw withdrawal latency in response to cold stimulation on days 4 and 5 post-immobilization (e) in the immobilization stress group. Mean ± SEM. *P < 0.05, **P < 0.01 vs the corresponding time points in the control group. N = 5/group