Nociceptive-like behavior and analgesia in silver catfish (Rhamdia quelen)

• Published in: Physiology & behavior 2019-10, Vol.210, p.112648-112648, Article 112648
• Main Authors: Rodrigues, Patrícia, Barbosa, Luísa Barichello, Bianchini, Adriane Erbice, Ferrari, Fabíola Tonelli, Baldisserotto, Bernardo, Heinzmann, Berta Maria
• Format: Article
• Language: English
• Subjects: Acetic acid; Animal model; Fish; Formalin; Menthol; Morphine
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/j.physbeh.2019.112648

Fish are useful animal models in research and have been employed in developing new pharmacological approaches. This study aimed to establish the use of silver catfish (Rhamdia quelen) as an animal model to evaluate antinociceptive activity. Initially, different concentrations of acetic acid (2.5–20%), formalin 1% (1–10 μL), menthol 0.5% (1–10 μL) or vehicle were injected in the lips to establish which concentration of each sample promotes nociceptive-like behavior in various parameters. The effect of morphine (0.5–10 mg/kg) on locomotion parameters was also evaluated for antinociceptive concentration determination. Morphine was administered intramuscularly immediately prior to algogen administration. The inhibition was evaluated with the antagonist naloxone (5 mg/kg), which was administered in the same way. Recording time varied according to the algogen used in each test and locomotor activity was evaluated by ANY-maze® software. Acid acetic at 15%, 10 μL of 1% formalin, and 1 μL of 0.5% menthol were chosen since they promoted nociceptive-like behavior in several parameters. Morphine (5 mg/kg) reversed the algogen-induced nociceptive-like behavior and naloxone inhibited this effect. Therefore, the proposed experimental model demonstrated specificity for nociception, since the reversion of the nociceptive-like behavior for a compound with well-described analgesic activity was observed. This new pharmacological model contributes to evaluating compounds with analgesic potential and developing new analgesic drugs, in addition to being a promising alternative to use with rodents. [Display omitted] •Algogens induce nociceptive-like behavior in silver catfish.•Ten behavioral parameters were evaluated in this experimental model.•Morphine 5 mg/kg reversed the algogen-induced nociceptive-like behavior.•Naloxone 5 mg/kg reverted morphine-induced analgesia.