Effects of partial decortication on opioid analgesia in the formalin test

Matthies, Brigitte K.; Franklin, Keith B.J.

doi:10.1016/0166-4328(94)00104-n

Cited by 22 publications

(5 citation statements)

References 57 publications

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“…Well-known for evaluating the effects of analgesic treatments on long-lasting pain, the formalin test also allows the recording of behavioral reactions relayed at different levels of the central nervous system [ 50 ]. Aside from the spinal cord, formalin-evoked responses seem to be mainly integrated in the brainstem and midbrain, as decerebration and decortication do not affect a range of behaviors [ 77 , 78 ]. Regarding the stereotypical nocifensive behaviors observed following formalin administration, it was shown that the persistence of limb flexion is largely a spinal reflex, as it can be evoked following chronic spinalization [ 79 ].…”

Section: Discussionmentioning

confidence: 99%

Evidence for a Role of NTS2 Receptors in the Modulation of Tonic Pain Sensitivity

et al. 2009

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Background: Central neurotensin (NT) administration results in a naloxone-insensitive antinociceptive response in animal models of acute and persistent pain. Both NTS1 and NTS2 receptors were shown to be required for different aspects of NT-induced analgesia. We recently demonstrated that NTS2 receptors were extensively associated with ascending nociceptive pathways, both at the level of the dorsal root ganglia and of the spinal dorsal horn. Then, we found that spinally administered NTS2-selective agonists induced dose-dependent antinociceptive responses in the acute tail-flick test. In the present study, we therefore investigated whether activation of spinal NTS2 receptors suppressed the persistent inflammatory pain symptoms observed after intraplantar injection of formalin.

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Section: Discussionmentioning

confidence: 99%

Evidence for a Role of NTS2 Receptors in the Modulation of Tonic Pain Sensitivity

et al. 2009

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“…These behaviours are sometimes considered as indicators of pain. However, rats continued to exhibit such behavioural responses following surgical decerebration (Matthies and Franklin 1992, 1995). One interpretation of these results is that pain is actually experienced in the brainstem, and not in the forebrain in rats.…”

Section: What Are the Reasons For The Anthropomorphic View That Fish mentioning

confidence: 99%

Fish do not feel pain and its implications for understanding phenomenal consciousness

Key

2014

Biol Philos

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Phenomenal consciousness or the subjective experience of feeling sensory stimuli is fundamental to human existence. Because of the ubiquity of their subjective experiences, humans seem to readily accept the anthropomorphic extension of these mental states to other animals. Humans will typically extrapolate feelings of pain to animals if they respond physiologically and behaviourally to noxious stimuli. The alternative view that fish instead respond to noxious stimuli reflexly and with a limited behavioural repertoire is defended within the context of our current understanding of the neuroanatomy and neurophysiology of mental states. Consequently, a set of fundamental properties of neural tissue necessary for feeling pain or experiencing affective states in vertebrates is proposed. While mammals and birds possess the prerequisite neural architecture for phenomenal consciousness, it is concluded that fish lack these essential characteristics and hence do not feel pain.

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“…Chapman [1] argued that they could be merely a measure of reflex activity instead of true pain sensation since reflexes can be exerted in spinalized or anesthetized animals. For example, the tail flick and paw withdrawal responses can be elicited in spinal animals [2] and therefore represent spinal reflexes; while vocalization [3] and paw licking on the hotplate test can be elicited in decerebrate animals [3][4][5][6] and therefore represent spinal-bulbospinal reflexes. Other investigators also suggest that changes in reflex activity might be due to alterations in motor as well as sensory processing [7,8].…”

Section: Introductionmentioning

confidence: 99%

Spared Nerve Injury Rats Exhibit Thermal Hyperalgesia on an Automated Operant Dynamic Thermal Escape Task

et al. 2005

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Well-established methods are available to measure thermal and mechanical sensitivity in awake behaving rats. However, they require experimenter manipulations and tend to emphasize reflexive behaviors. Here we introduce a new behavioral test, with which we examine thermal sensitivity of rats with neuropathic injury. We contrast thermal hyperalgesia between spared nerve injury and chronic constriction injury rats. This device is a fully automated thermal sensitivity assessment tool designed to emphasize integrated learned responses to thermal painful and non-painful stimuli that are applied dynamically to a surface on which the animal is standing. It documents escape behavior in awake, unrestrained animals to innocuous and noxious heating of the floor where the animal is located. Animals learn to minimize pain by escaping to the opposite non-heated side; escape latency is recorded. On this device, thermal stimulus-response curves showed > 6°C leftward shift in both groups of neuropathic rats. In contrast, when these animals were tested on hotplate the stimulusresponse shift was < 2°C. Spared nerve injury rats showed even less evidence for thermal hyperalgesia when thermal sensitivity was tested by measuring paw withdrawal to infrared heating, plantar test. The implications of test dependent magnitude of thermal hyperalgesia are discussed from the viewpoint of the tests used, as well as the animal models studied. It is argued that the dynamic thermal operant task reveals the relevance of the neuropathic injury associated pain-like behavior in relation to the whole organism.

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Effects of partial decortication on opioid analgesia in the formalin test

Cited by 22 publications

References 57 publications

Evidence for a Role of NTS2 Receptors in the Modulation of Tonic Pain Sensitivity

Evidence for a Role of NTS2 Receptors in the Modulation of Tonic Pain Sensitivity

Fish do not feel pain and its implications for understanding phenomenal consciousness

Spared Nerve Injury Rats Exhibit Thermal Hyperalgesia on an Automated Operant Dynamic Thermal Escape Task

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