Effects of the Subcutaneous Administration of Morphine (5 mg/kg), DPDPE (5 mg/kg), or JWH-015 (3 mg/kg) Alone or Combined with CTAP (4 mg/kg) or NX-ME (1 mg/kg), Naltrindole (2 mg/kg), or NX-ME (1 mg/kg), and AM630 (1 mg/kg) or AM251 (5 mg/kg), Respectively, on the Mechanical Allodynia, Thermal Hyperalgesia, and Thermal Allodynia Induced by Injury in the Ipsilateral Paw of Sciatic Nerve-injured Animals