Arm injury produces long-term behavioral and neural hypersensitivity in octopus.
Cephalopod molluscs are the most neurally and behaviorally complex invertebrates, with brains rivaling those of some vertebrates in size and complexity. This has fostered the opinion that cephalopods, particularly octopuses, may experience vertebrate-like pain when injured. However, it is not known whether octopuses possess nociceptors or if their somatic sensory neurons exhibit sensitization after injury. Here we show that the octopus Abdopus aculeatus expresses nocifensive behaviors including arm autotomy, and displays marked neural hyperexcitability both in injured and uninjured arms for at least 24h after injury. These findings do not demonstrate that octopuses experience pain-like states; instead they add to the minimal existing literature on how cephalopods receive, process, and integrate noxious sensory information, potentially informing and refining regulations governing use of cephalopods in scientific research.
Department of Integrative Biology, University of California, Berkeley, CA, United States.
Jean S
JS
Alupay
Department of Psychology, Brooklyn College of the City University of New York, Brooklyn, NY, United States.
Stavros P
SP
Hadjisolomou
Department of Integrative Biology and Pharmacology, University of Texas Medical School, Houston, TX, United States; Program in Sensory Physiology and Behavior, Marine Biological Laboratory, Woods Hole, MA, United States. Electronic address: Robyn.crook@uth.tmc.edu.
Robyn J
RJ
Crook
D000818:Animals; D001522:Behavior, Animal; D004924:Escape Reaction; D005121:Extremities / Q000293:injuries; D059225:Nociception; D049831:Octopodiformes / Q000502:physiology*; D012018:Reflex; D012684:Sensory Thresholds; D013997:Time Factors
Autotomy; Cephalopod; Nociception; Octopus; Pain; Sensitization