• Biomolecules & Therapeutics
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• 제27권2호
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• pp.168-177
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• 2019

Dysregulation of excitatory neurotransmission has been implicated in the pathogenesis of neuropsychiatric disorders. Pharmacological inhibition of N-methyl-D-aspartate (NMDA) receptors is widely used to model neurobehavioral pathologies and underlying mechanisms. There is ample evidence that overstimulation of NMDA-dependent neurotransmission may induce neurobehavioral abnormalities, such as repetitive behaviors and hypersensitization to nociception and cognitive disruption, pharmacological modeling using NMDA has been limited due to the induction of neurotoxicity and blood brain barrier breakdown, especially in young animals. In this study, we examined the effects of intraperitoneal NMDA-administration on nociceptive and repetitive behaviors in ICR mice. Intraperitoneal injection of NMDA induced repetitive grooming and tail biting/licking behaviors in a dose- and age-dependent manner. Nociceptive and repetitive behaviors were more prominent in juvenile mice than adult mice. We did not observe extensive blood brain barrier breakdown or neuronal cell death after peritoneal injection of NMDA, indicating limited neurotoxic effects despite a significant increase in NMDA concentration in the cerebrospinal fluid. These findings suggest that the observed behavioral changes were not mediated by general NMDA toxicity. In the hot plate test, we found that the latency of paw licking and jumping decreased in the NMDA-exposed mice especially in the 75 mg/kg group, suggesting increased nociceptive sensitivity in NMDA-treated animals. Repetitive behaviors and increased pain sensitivity are often comorbid in psychiatric disorders (e.g., autism spectrum disorder). Therefore, the behavioral characteristics of intraperitoneal NMDA-administered mice described herein may be valuable for studying the mechanisms underlying relevant disorders and screening candidate therapeutic molecules.

• Advances in Traditional Medicine
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• 제7권5호
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• pp.501-508
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• 2008

Anti-nociceptive and anti-inflammatory effects of Clematidis Radix (CR)-distillates were investigated in three different pain animal models. Highly purified distillate of CR was injected to Zusanli (ST36) acupoint, called CR herb-acupuncture in the Korean traditional medicine. In tail flick latency test, the CR herb-acupuncture treatment did not show a significant effect of relieving acute phasic pain. To investigate the anti-inflammatory effect of CR herb-acupuncture, inflammatory pain was induced by subcutaneous injection of formalin to the plantar tissue or intra-articular injection of carrageenan to the tibio-tarsal joint in the rats. And the medicinal effect of CR herb-acupuncture was evaluated by analyzing pain behavior such as licking or biting behavior, or by measuring weight distribution ratio between two foot and ankle circumference. In the rat formalin test, the analgesic effect of CR herb-acupuncture was more pronounced in the late phase (for 20 min after the early phase) than in the early phase (for the first 10 min post formalin injection). It also significantly alleviated the carrageenan-induced monoarthritis, in terms of weight distribution ratio and ankle edema. These results revealed that CR herb-acupuncture was effective to treat the inflammatory pain and could be used as an analgesic treatment with an antiinflammatory effect.

• Journal of Acupuncture Research
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• 제21권2호
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• pp.223-233
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• 2004

Objective: As a manual accupucture method, the twirling-needle treatment has been known more effective in relieving pain than the conventional simple accupuncture treatment. Finding a proper treatment condition is difficult because of the lack of a quantative measurement of the alleviation of pain made by acupuncture. In this research, the authors propose the use of infrared thermal images in a formalin test to quantatively verify the effect of twirling. Methods: After injecting 10%~20% formalin into the tail of rats, the infrared thermal images(ITI) have been obtained to estimate the thermal distribution caused by inflammation. The authors propose a processing method to measure the thermal distribution from the thermal images obtained from the infrared camera as a pain model of the formalin test. Results: The pain model obtained from the infrared thermal image has two phases. The first phase, which is a transient period, is the initial 20 minutes when the pain is developed after the formalin injection. The second phase, which is a steady state, is where the development of pain lasts for 60 minutes or more after the first stage. This characteristic of the proposed model based on ITI is consistent with that of the pain model reported by other researchers whose works are based on the time-course of flinching and licking/biting, following a different concentration of formalin. It is noticed that the response of the thermal distribution obtained from ITI shows very high correlation to the behavioral response in the formalin test performed by Kazuhiro Okuda and four others5). In addition, the authors propose an ITI method to determine the pain-reducing effect of the acupuncture. The thermal distribution obtained from the experiment shows that there is significant pain reducing effect made by the twirling-needle method.