Behavioral control of the efficiency of pharmacological anesthesia in fish
- 97 Downloads
An original behavioral test was used to study the effect of opioid substances on the thresholds of nociceptive responses to pain stimuli—a series of electric impulses applied to nerve endings of the caudal fin—in the common carp (Cyprinus carpio). The substances tested included tramadol (μ-agonist of opioid receptors), DADLE (δ-agonist), and U-50488 (κ-agonist) injected intramuscularly in concentrations 10–100 nmol/g of body weight. Raised thresholds of sensitivity to the pain stimulus were observed in the studied fish 5 to 15 min after the injection. The degree of analgesia and the rate of its increase varied depending on the dose. The total duration of analgesia was 40 to 90 min and depended on the concentration of the injected substance. It was observed in some experiments that the analgesic effect of tramadol (the most efficient of the analgesics used) could last longer than 4 h. The analgesic effect of opioids was not detected in experiments where they were applied together with naloxone, an antagonist of opioids. Decreased motor response to pain stimuli after injections of analgesics was not caused by the immobilization of the animal, because the tested fish individuals released into an aquarium demonstrated normal swimming and their usual behavior. We concluded that the systems of opioid nociceptive regulation function similarly in fish and land vertebrates. This regulation can play an important role in defense behavior and in other behaviors in fish.
Keywordsfish nociception pain analgesia opioids tramadol behavioral test Cyprinus carpio
Unable to display preview. Download preview PDF.
- Charpentier, J., Analysis and Measurement of Pain in Animals, a New Conception of Pain, Pain, Soulairac, A., et al., Eds., L.: Acad. Press, 1968, pp. 171–200.Google Scholar
- Chervova, L.S., Electrophysiological Investigation of the Trigeminal Nerve Innervated the Olfactory Organ of White Sea Cod Gadus morhua marisalbi, J. Ichthyol., 1985, vol. 25. No. 4, pp. 293–298.Google Scholar
- Chervova, L.S., Pain Sensitivity and Behavior of Fishes, J. Ichthyol., 1997, vol. 37, no. 1, pp. 98–102.Google Scholar
- Chervova, L.S., Kamenskii, A.A., Malyukina, G.A., et al., Investigation of the Mechanism of Intranasal Effect of Dermorphin in Representatives of Two Classes of Vertebrates, Zh. Evol. Biokhim. Fiziol., 1992, vol. 28, no. 1, pp. 45–48.Google Scholar
- Chervova, L.S., Lapshin, D.N., and Kamenskii, A.A., Pain Sensitivity of Trout and Analgesia Induced by Intranasal Administration of Dermorphine, Dokl. Biol. Sci., 1994, vol. 338, pp. 424–425.Google Scholar
- VIIth Congress on Biology of Fish, 2006, 18–22 July, St.-John’s, Canada, Abstracts.Google Scholar
- Lynn, B., The Fibre Composition of Cutaneous Nerves and the Classification and Response Properties of Cutaneous Afferents, with Particular Reference to Nociception, Pain Rev., 1994, vol. 1, pp. 172–183.Google Scholar
- Newby, N.C., Mendonça, P.C., Gamperl, K., and Stevens, D.E., Pharmacokinetics of Morphine in Fish: Winter Flounder (Pseudopleuronectes americanus) and Seawater-Acclimated Rainbow Trout (Oncorhynchus mykiss), Comp. Biochem. Physiol., C, 2006, vol. 143, pp. 275–283.Google Scholar