Neuroscience letters
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Neuroscience letters · Sep 2011
Antinociceptive effects of neurotropin in a rat model of central neuropathic pain: DSP-4 induced noradrenergic lesion.
Neurotropin is a nonprotein extract isolated from inflamed skin of rabbits inoculated with vaccinia virus, and used for treatment of neuropathic pain. In the present study, we have determined whether neurotropin could exert antinociceptive action using the central neuropathic pain model that we recently established. Rats were randomly allocated to 3 groups: Sham group (n=20), DSP-4 [N-(-2-chloroethyl)-N-ethyl-2-bromobenzylamine] group (50mg/kg ip, n=18), and DSP-4+5,7-DHT [5,7-dihydroxytryptamine] group (ip DSP-4 50mg/kg+icv 5,7-DHT 200μg, n=18). ⋯ There was a significant correlation between AUC and norepinephrine contents in saline subgroup (p<0.01, r=0.597) but not in neurotropin subgroup in DSP-4 group. Neurotropin exerted an antinociceptive effect in DSP-4 induced central neuropathic pain. The present data suggest neuronal pathways other than descending inhibitory noradrenergic and serotonergic systems may be involved in neurotropin mediated antinociception.
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Neuroscience letters · Sep 2011
Semantic fluency and executive functions as candidate endophenotypes for the early diagnosis of schizophrenia in Han Chinese.
Neurocognitive deficits are recognized as core features of schizophrenia. The aim of this study was to compare the cognitive performance of antipsychotic, drug-naive patients with first-episode schizophrenia (FES patients) to their healthy siblings and to healthy controls from the Han Chinese population for exploring potential endophenotypes for the early detection of schizophrenia. A battery of cognitive assessment tools was used to measure seven cognitive domains in matched groups consisting of 56 subjects each. ⋯ Patients' performances were lower than siblings' on all tests except for the CFT, the WMS-III SST backward test, and four subtests of the WCST-64. Our data suggest that FEP patients exhibited pronounced impairment of fine motor skills, speed of processing, attention, verbal memory, visual memory, and executive function, while siblings exhibited deficits intermediate between those of schizophrenic patients and the control group. Semantic fluency function and executive function may be potential endophenotypes for the early diagnosis of schizophrenia.
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Neuroscience letters · Sep 2011
Galanin modulating effect on restraint stress-induced short- and long-term behavioral changes in Wistar rats.
The neuropeptide galanin has been recognized as a possible neurotransmitter/neuromodulator, and in addition has been implicated in anxiety- and depression-related behaviors. The present study demonstrates increased locomotion and rearing after galanin (0.3mg/kg) that was given intraperitoneally (i.p.) to intact Wistar rats which were tested 1h later in the open field (OF). These effects, which suggest an anxiolytic-like action, were blocked by i.p. administered peptidic galanin antagonist M40. ⋯ Testing performed on the 12th day after the last stress and galanin treatment with 0.3mg/kg revealed an increased locomotion compared with unstressed and stress-exposed rats. Our results demonstrate that behavioral effects of the peptide galanin are evident even after i.p. administration. These results also suggest that galanin elicits stress-modulatory action, and support the notion that the galaninergic system may serve as a drug target in stress-related conditions.
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Neuroscience letters · Sep 2011
Controlled Clinical TrialAbnormal spontaneous brain activity in medication-naïve ADHD children: a resting state fMRI study.
Abnormal baseline brain functional connectivity in attention-deficit/hyperactivity disorder (ADHD) has been revealed in a number of studies by using resting-state functional MRI (rfMRI). The aim of this study was to investigate the spontaneous frontal activities in medication-naïve ADHD boys using the rfMRI derived index, amplitude of low-frequency fluctuation (ALFF). In total 17 ADHD boys and 17 matched controls were recruited to undergo rfMRI scan on a 3.0T MRI system. ⋯ With a corrected threshold of p<0.05 determined by AlphaSim, we found that in comparison with controls, ADHD patients demonstrated higher ALFF values in the left superior frontal gyrus and sensorimotor cortex (SMC), and lower ALFF values in the bilateral anterior, middle cingulate and the right middle frontal gyrus (MFG). Significant correlations were found between patients' WSCT measures and the peak ALFF located in the right MFG (r=0.69, p=0.02), and the left SMC (r=0.65, p=0.03). Our results revealed abnormal frontal activities at resting state associated with underlying physiopathology of ADHD, and suggested the ALFF analysis to be a potential approach in further exploration of this disorder.
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Neuroscience letters · Sep 2011
Up-regulation of spinal glutamate transporters contributes to anti-hypersensitive effects of valproate in rats after peripheral nerve injury.
Valproate produces analgesia in animals and humans, however, its mechanisms of action are yet unknown. The present study examined effects of repeated administration of valproate on behavioral hypersensitivity and expression of glutamate transporter-1 (GLT-1) and glutamate-aspartate transporter (GLAST) in the spinal dorsal horn in rats after L5-L6 spinal nerve ligation (SNL). ⋯ This analgesia from valproate was blocked by the selective GLT-1 blocker dihydrokainic acid (DHK). These data suggest that valproate restores down-regulated expression of glutamate transporters in the spinal cord to presumably reduce glutamate signaling and to reduce hypersensitivity after nerve injury, and that combination of valproate with riluzole produces enhanced analgesia which relies on the spinal glutamate transporters.