Neuroscience letters
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Neuroscience letters · Oct 2009
Effect of high trait anxiety on mechanical hypersensitivity in male rats.
Recently, we have shown that neuropathic pain is associated with anxiety-like behaviour in rats with sciatic nerve lesion. An enhanced pain perception has also been described in patients with anxiety disorders. However, there is only limited knowledge about the relationship between anxiety and pain in animals. ⋯ In the EPM anxiety-like behaviour was observed following CCI injury in HAB and LAB rats on top of low and high trait anxiety reflected in a reduced number of entries in open arms. These findings indicate that trait anxiety increases mechanical hypersensitivity in CCI rats during the chronic phase of pain, thereby suggesting that affective processes modulate even simple pain-related behaviour. Furthermore, we demonstrated that neuropathic pain in the CCI model increases anxiety-like behaviour even in LAB rats.
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Neuroscience letters · Oct 2009
Mental slowness and executive dysfunctions in patients with metabolic syndrome.
Metabolic Syndrome is a cluster of vascular risk factors which has been related to dementia and cognitive decline. The aim of this study was to describe the neuropsychological profile of metabolic syndrome patients. ⋯ There were differences between groups in speed of processing and some executive functions after controlling for the influences of education and gender. The results suggest that metabolic syndrome may be a prodromal state of vascular cognitive impairment.
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Neuroscience letters · Oct 2009
Can Cantonese rhymes be used in the assessment of hemispheric dominance for language?
English vowels had been proposed in previous studies to be used as a simple tool for the brain mapping of language. A proper fMRI study of Cantonese rhymes, each of which being a required and fundamental unit of a Cantonese syllable, remains to be carried out. ⋯ Typical language activating regions of the prefrontal cortex, the medial prefrontal cortex and the lateral temporal cortex on both left and right sides were not activated by Cantonese rhymes. Based on the absence of brain activation at the typical language areas in the contrast of Cantonese rhymes relative to filtered sounds, the auditory task with Cantonese rhymes may not be a robust tool for the individual clinical assessment of hemispheric dominance for language.
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Neuroscience letters · Oct 2009
Acute and chronic fentanyl administration causes hyperalgesia independently of opioid receptor activity in mice.
Although mu-receptor opioids are clinically important analgesics, they can also paradoxically cause hyperalgesia independently of opioid receptor activity, presumably via the action of neuroexcitatory glucoronide metabolites. However, it is unknown whether the commonly used mu-receptor opioid analgesic fentanyl, which is not subject to glucuronidation, can also induce hyperalgesia independently of opioid receptor activity. Thus, here we examined whether fentanyl increases nociception on the tail-withdrawal test in CD-1 mice concurrently treated with the opioid receptor antagonist naltrexone or in opioid receptor triple knock-out mice lacking mu, delta, and kappa opioid receptors. ⋯ MK-801 blocked and reversed hyperalgesia caused by the acute injection and continuous infusion of fentanyl, respectively, in naltrexone-treated CD-1 mice, indicating the contribution of NMDA receptors to fentanyl hyperalgesia. These data show that the synthetic opioid fentanyl causes hyperalgesia independently of prior or concurrent opioid receptor activity or analgesia. Since the biotransformation of fentanyl does not yield any known pronociceptive metabolites, these data challenge assumptions regarding the role of neuroexcitatory metabolites in opioid-induced hyperalgesia.