Neuroscience letters
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Neuroscience letters · Sep 2017
Changes of brain structure in Parkinson's disease patients with mild cognitive impairment analyzed via VBM technology.
To analyze changes in cerebral grey matter volume and white matter density in non-dementia Parkinson's disease patients using voxel-based morphometry (VBM) technology; to investigate features of brain structure changes in Parkinson's disease patients with mild cognitive impairment (PD-MCI), and reveal their intrinsic pathological changes. ⋯ Structural changes in PD-MCI patients are associated with overall cognitive function, and the atrophic areas are mainly located in the frontal and limbic system, and are dominated by subcortical atrophy. Moreover, atrophy of limbic lobes is associated with impaired memory, whereas frontal lobe atrophy is associated with executive dysfunction. In addition, the subtle brain structure of the PD early cognitive impairment stage and PD-MCI stage can be detected via VBM technology, and thus, local brain atrophy may be a neuroimaging marker for the early diagnosis of PD-MCI.
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Neuroscience letters · Sep 2017
Systemic dexmedetomidine attenuates mechanical allodynia through extracellular sign db type 2 diabetic mice.
Painful diabetic neuropathy (PDN) is a common complication of diabetes mellitus. However, the treatment for PDN is limited in clinical practice. In the present study, we investigated the effect of systemic administration dexmedetomidine (DEX), a selective alpha 2 adrenergic receptor (α2AR) agonist, on mechanical allodynia and its underlying mechanism in db/db mice, an animal model of type 2 diabetes mellitus. ⋯ Furthermore, the upregulation of pERK1 and pERK2 in db/db mice were attenuated by preadministration of dexmedetomidine. We provide the first evidence that the functional alternation of spinal noradrenergic system might underlie exaggerated nociception in PDN. Systemic dexmedetomidine inhibits the mechanical allodynia which is related to ERK signaling pathway in type 2 diabetes, implying that the α2-Adrenoceptor might be a potential therapeutic strategy for PDN.
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Neuroscience letters · Sep 2017
Valproic acid exposure decreases the mRNA stability of Bcl-2 via up-regulating miR-34a in the cerebellum of rat.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interaction, limited verbal communication and repetitive behaviors. Previous studies have shown that the level of Bcl-2 in the brain tissues of ASD patients is significantly decreased. However, the mechanisms underlie the down-regulation of Bcl-2 in ASD is still unknown. ⋯ Meanwhile, VPA exposure up-regulated the expression of miR-34a in cerebellar cortex and primary cerebellar cortical neuronal cells. The mimics of miR-34a directly inhibited the expression of Bcl-2 and its antagonist blocked the down-regulation effect of VPA on Bcl-2 in primary cerebellar cortical neuronal cells. Our study implies that VPA may influence ASD through sequential up-regulating miR-34a and therefore down-regulating Bcl-2 in the brain tissues of rats.
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Neuroscience letters · Sep 2017
β-Lactamase inhibitor, clavulanic acid, attenuates ethanol intake and increases glial glutamate transporters expression in alcohol preferring rats.
Studies from our laboratory showed that upregulation of glutamate transporter 1 (GLT-1) and cystine-glutamate exchanger (xCT) expression with ceftriaxone, β-lactam antibiotic, in the brain was associated with attenuation of ethanol consumption. In this study, we tested clavulanic acid, which is another β-lactam compound with negligible antimicrobial activity, on ethanol consumption and expression of GLT-1, xCT and glutamate aspartate transporter (GLAST) in male alcohol-preferring (P) rats. Clavulanic acid has the central β-lactam pharmacophore that is critical for the upregulation of GLT-1 and xCT expression. ⋯ Clavulanic acid treatment did not upregulate the expression of GLT-1, xCT and GLAST in prefrontal cortex. These findings revealed that clavulanic acid at 20-40 fold lower dose than ceftriaxone can attenuate ethanol consumption, in part through upregulation of GLT-1 and xCT expression in the nucleus accumbens. Thus, we suggest that clavulanic acid might be used as an alternative option to ceftriaxone to attenuate ethanol drinking behavior.
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Neuroscience letters · Jul 2017
Suppressed neural complexity during ketamine- and propofol-induced unconsciousness.
Ketamine and propofol have distinctively different molecular mechanisms of action and neurophysiological features, although both induce loss of consciousness. Therefore, identifying a common feature of ketamine- and propofol-induced unconsciousness would provide insight into the underlying mechanism of losing consciousness. In this study we search for a common feature by applying the concept of type-II complexity, and argue that neural complexity is essential for a brain to maintain consciousness. ⋯ For the analysis, we use Mean Information Gain (MIG) and Fluctuation Complexity (FC), which are information-theory-based measures that quantify disorder and complexity of dynamics respectively. Both ketamine and propofol reduced the complexity of the EEG signal, but ketamine increased the randomness of the signal and propofol decreased it. The finding supports our claim and suggests EEG complexity as a candidate for a consciousness indicator.