Fig 1.
Change of thermal hyperalgesia in neuropathic pain model mice.
Schematic diagram of sciatic nerve ligation (A). Plantar tests were performed before nerve ligation surgery, 7, 8 and 9 days after surgery. Data are expressed as means ± SEM. Data are analyzed using two-way ANOVA followed by Bonferroni’s post hoc test and considered statistically significant at ****P < 0.0001 when comparing the sham (n = 8) and nerve ligation groups (n = 8) (B).
Fig 2.
Amitriptyline improved thermal hyperalgesia in neuropathic pain model.
Plantar tests were performed before nerve ligation surgery, test day 7 with vehicle, and test day 8 with amitriptyline administration (n = 8) (A). Schematic diagram of plantar test (B). Paw withdrawal latencies were plotted for every test (C). Data are expressed as means ± SEM. Data are analyzed using two-way ANOVA followed by Bonferroni’s post hoc test and considered statistically significant at ****P < 0.0001 when comparing the sham and ligation groups.
Fig 3.
Amitriptyline improved quantity of sleep in neuropathic pain model.
EEG and EMG were recorded for 24 hours with administration of vehicle (test day 7) and amitriptyline (test day 9) (A). Schematic diagram of EEG/EMG implantation (B). The mean value per hour of wake, REM sleep, and non-REM sleep time are represented for the sham (n = 7) and nerve ligation groups (n = 7) (C). Data are expressed as means ± SEM. Data are analyzed using two-way ANOVA followed by Bonferroni’s post hoc test and considered statistically significant at ***P < 0.001, and ****P < 0.0001 when comparing the groups.
Fig 4.
Amitriptyline improved quality of sleep in neuropathic pain model.
Distribution of EEG power density in each frequency during non-REM and REM sleep. Data are expressed as means only. *P < 0.05 at 4.2 Hz and 4.7 Hz when comparing sham-vehicle and ligation-vehicle groups (A). Time changes of the normalized power density of δ wave were plotted every 3 hours in sham (n = 5–7) and nerve ligation (n = 7) mice. Data are expressed as means ± SEM (B) and are analyzed using two-way ANOVA followed by Bonferroni’s post hoc test and considered statistically significant at **P < 0.01 when comparing sham-vehicle and ligation-vehicle groups, ##P < 0.01 when comparing ligation-vehicle and ligation amitriptyline group, and +++P < 0.001 when comparing the sham-amitriptyline and ligation-vehicle groups.
Fig 5.
Selective 5HT2A receptor antagonist improved thermal hyperalgesia in neuropathic pain model.
Plantar tests were performed before nerve ligation surgery, on test day 7 with vehicle, and on test day 8 with MDL 100907 administration (n = 8) (A). Paw withdrawal latencies were plotted for every test. Data are expressed as means ± SEM. Data are analyzed using two-way ANOVA followed by Bonferroni’s post hoc test and considered statistically significant at ****P < 0.0001 when comparing the sham and ligation groups (B).
Fig 6.
Selective 5HT2A receptor antagonist improved quantity of sleep in neuropathic pain model.
EEG and EMG were recorded for 24 hours with administration of vehicle (test day 7) and MDL 100907 (test day 9) (A). The mean value per hour of wake, REM sleep, and non-REM sleep time are represented for sham (n = 7) and nerve ligation groups (n = 7). Data are expressed as means ± SEM. Data are analyzed using two-way ANOVA followed by Bonferroni’s post hoc test and considered statistically significant at ***P < 0.001, and ****P < 0.0001 when comparing all groups (B).
Fig 7.
Selective 5HT2A receptor antagonist improved quality of sleep in neuropathic pain model.
Distribution of EEG power density in each frequency during non-REM and REM sleep. Data are expressed as means only (A). Time changes of the normalized power density of δ wave are plotted every 3 hours in sham (n = 6) and nerve ligation (n = 5) mice. Data are expressed as means ± SEM (B). Data are analyzed using two-way ANOVA followed by Bonferroni’s post hoc test and considered statistically significant at *P < 0.05 when comparing the sham-vehicle and ligation-vehicle groups, #P < 0.05 when comparing the ligation-vehicle and ligation-MDL 100907 groups, and +P < 0.05 when comparing the sham-amitriptyline and ligation-vehicle groups.