Neuroscience letters
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Neuroscience letters · Jan 2013
Neuroprotective effect of erythropoietin on nandrolone decanoate-induced brain injury in rats.
Anabolic-androgenic steroids (AAS) are used in the medical treatment of many disorders. Erythropoietin (EPO) is a hematopoietic cytokine that has anti-apoptotic, anti-oxidative, and anti-inflammatory effects. The aim of the present study is to investigate the neuroprotective effects of EPO in the hippocampus, parietal cortex and prefrontal cortex, in brain damage due to nandrolone decanoate. 35 Wistar male rats were randomly divided into: (1) control group, (2) sham group, (3) nandrolone decanoate group (ND, intramuscular, 10 mg/(kg week), 8 weeks), (4) ND+low dose EPO treated group (ND+L-EPO) and (5) ND+high dose EPO treated group (ND+H-EPO). ⋯ Treatment with H-EPO significantly preserved the number of neurons in hippocampus when compared with ND administrated. Besides, H-EPO treatment decreased the number of TUNEL-positive and active caspase-3 positive cells and MDA levels and increased GPx levels when compared to ND group. In conclusion, abuse of AAS causes reduction in the number of neurons in hippocampus, parietal cortex and prefrontal cortex regions and increases oxidative damage and therefore H-EPO may be useful as a neuroprotective agent in brain injury.
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Neuroscience letters · Dec 2012
Chronic dopamine depletion augments the functional expression of K-ATP channels in the rat subthalamic nucleus.
Symptoms of Parkinson's disease caused by dopamine depletion are associated with burst firing in the subthalamic nucleus (STN). Moreover, regularization or suppression of STN neuronal activity is thought to improve symptoms of Parkinson's disease. We reported recently that N-methyl-D-aspartate (NMDA) receptor stimulation of rat STN neurons evokes ATP-sensitive K(+) (K-ATP) current via a Ca(2+)- and nitric oxide-dependent mechanism. ⋯ Moreover, extracellular, loose-patch recordings showed that NMDA increased spontaneous firing rate in STN neurons in slices from normal rats, whereas NMDA produced a tolbutamide-sensitive inhibition of firing rate in STN neurons located ipsilateral to 6-OHDA treatment. These results show that K-ATP channel function in STN neurons is up-regulated by chronic dopamine deficiency. We suggest that K-ATP channel activation in the STN might benefit symptoms of Parkinson's disease.
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Neuroscience letters · Dec 2012
Different functional reorganization of motor cortex after transfer of the contralateral C7 to different recipient nerves in young rats with total brachial plexus root avulsion.
Clinically, contralateral C7 transfer is used for nerve reconstruction in brachial plexus injuries. Postoperatively, synchronous motions at the donor limb are noteworthy. This study studied if different recipient nerves influenced transhemispheric functional reorganization of motor cortex after this procedure. 90 young rats with total root avulsion of the brachial plexus were divided into groups 1-3 of contralateral C7 transfer to anterior division of the upper trunk, to both the musculocutaneous and median nerves, and to the median nerve, respectively. ⋯ Logistic regression analysis showed that rate of fulfilled transhemispheric reorganization in group 1 was 12.19 times that in group 3 (95% CI 0.006-0.651, p=0.032). At 12 months, number of sites for hindlimb representations which had encroached upon original forelimb representations on the uninjured side was statistically more in group 3 than in group 2 (t=9.5, p<0.0001). It is concluded that contralateral C7 transfer to upper trunk or to both the musculocutaneous and median nerves induces faster transhemispheric functional reorganization of motor cortex than that to median nerve alone in rats.
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Neuroscience letters · Dec 2012
The involvement of Type II Neuregulin-1 in rat visuospatial learning and memory.
The cognitive deficits observed in schizophrenia are considered a core feature of the disease. Neuregulin-1 is a risk gene for schizophrenia that is involved in many neurodevelopmental and synaptic plasticity-related processes relevant to schizophrenia. Here, we have utilized a rat model (Nrg1(Tn)), which is hypomorphic for the neuregulin-1 (Nrg1) gene, to test whether reduced Type II NRG1 in the rat brain leads to cognitive deficits relevant to schizophrenia. ⋯ Nrg1(Tn) rats were not impaired on the Morris water maze, but did show a deficit in the appetitive visuospatial discrimination test. Nrg1(Tn) rats committed more reference and working memory errors in this test. These results indicate that decreased Type II NRG1 in the brain may lead to deficits in visuospatial learning and memory.
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Neuroscience letters · Nov 2012
Right lateralized white matter abnormalities in first-episode, drug-naive paranoid schizophrenia.
Numerous studies in first-episode schizophrenia suggest the involvement of white matter (WM) abnormalities in multiple regions underlying the pathogenesis of this condition. However, there has never been a neuroimaging study in patients with first-episode, drug-naive paranoid schizophrenia by using tract-based spatial statistics (TBSS) method. Here, we used diffusion tensor imaging (DTI) with TBSS method to investigate the brain WM integrity in patients with first-episode, drug-naive paranoid schizophrenia. ⋯ Patients did not have increased FA values in any brain regions compared to healthy subjects. There was no correlation between the FA values in any brain regions and patient demographics and the severity of illness. Our findings suggest right-sided alterations of WM integrity in the WM tracts of cortical and subcortical regions may play an important role in the pathogenesis of paranoid schizophrenia.