Huperzine A Alleviates Mechanical Allodynia but Not Spontaneous Pain via Muscarinic Acetylcholine Receptors in Mice

Figure 2

Systemic injection of clonidine but not Hup A alleviated spontaneous neuropathic pain as assessed in the CPP test. (a) Times spent in the chambers during the preconditioning period (two-way RM ANOVA, groups: , ; saline versus drug: , , for Hup 0.1, clonidine group, for Hup 0.15). (b) Clonidine but not Hup A (0.1 mg/kg and 0.15 mg/kg) induced preference for the drug-paired chamber (two-way RM ANOVA, groups: , ; saline versus drug: , , for Hup 0.1, clonidine group, for Hup 0.15, under SNK test). (c) Preference times induced by Hup A and clonidine in mice with nerve injury (one-way ANOVA, , , for Hup 0.1, clonidine group, for Hup 0.15, under SNK test). (d) Time spent by mice in the chambers in the saline- and CFA-injected groups during the preconditioning period (two-way RM ANOVA, groups: , ; saline versus drug: ,, for saline-Hup A, for CFA-Hup A, for CFA-Clo.). (e) Clonidine but not Hup A induced preference for the drug-paired chamber by CFA-injected mice (two-way RM ANOVA, groups: , ; saline versus drug: , , for saline-Hup A, for CFA-Hup A, and for CFA-Clo.; under SNK test). (f) Preference times of mice with CFA injection induced by Hup A and clonidine (one-way ANOVA, , , under SNK test). (g) Time spent by mice in the chambers in the saline- and CFA-injected groups during the preconditioning period for multitrial conditioning (two-way RM ANOVA, groups: , ; saline versus drug: , , for saline-Hup A, for CFA-Hup A). (h) Hup A (0.1 mg/kg) did not induce preference for the drug-paired chamber by CFA-injected mice in the multitrial conditioning (two-way RM ANOVA, groups: , ; saline versus drug: , , for saline-Hup A, for CFA-Hup A). (i) Preference times of mice with CFA injection induced by Hup A in the multitrial conditioning (t-test, ).

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