Molecular neurobiology
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Molecular neurobiology · May 2016
Plasma Homocysteine Levels Predict the Risk of Acute Cerebral Infarction in Patients with Carotid Artery Lesions.
This study examined the association between elevated plasma homocysteine (Hcy) levels and the risk of acute cerebral infarction in patients with carotid artery lesions. A total of 78 patients were divided into two groups, the high Hcy group (n = 38; Hcy levels >15 umol/L) and the low Hcy group (n = 40; Hcy levels ≤15 umol/L). High-resolution B-mode ultrasounds were performed to assess intima media thickness (IMT), infarcts, plaques, and stenosis in the extracranial carotid artery of these patients. ⋯ Pearson's test indicated that plasma Hcy levels positively correlated with IMT, total number of plaques and unstable plaques. Overall, the elevated plasma Hcy levels correlated with increased frequency of carotid plaque formation, extra- and intracranial arterial stenosis, and the degree of stenosis. In conclusion, we find a significant correlation between elevated plasma Hcy levels and the increased incidence of acute cerebral infarction in patients with carotid artery lesions.
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Molecular neurobiology · May 2016
Dexmedetomidine Dose-Dependently Attenuates Ropivacaine-Induced Seizures and Negative Emotions Via Inhibiting Phosphorylation of Amygdala Extracellular Signal-Regulated Kinase in Mice.
Ropivacaine (Ropi), one of the newest and safest amino amide local anesthetics, is linked to toxicity, including the potential for seizures, changes in behavior, and even cardiovascular collapse. Dexmedetomidine (Dex), an α2-adrenergic receptor agonist, has been widely used in anesthesia and critical care practice. To date, the underlying mechanisms of the effects of Dex premedication on Ropi-induced toxicity have not been clearly identified. ⋯ Open-field (OF) and elevated plus maze (EPM) test were used to measure negative behavioral emotions such as depression and anxiety. Immunohistochemistry and Western blot were utilized to investigate phosphorylation-extracellular regulated protein kinases (p-ERK) expression in the basolateral amygdala (BLA) on 2 h and in the central amygdala (CeA) on 24 h after convulsion in mice. The results of our investigation demonstrated that Dex dose-dependently increased RopiCD50, prolonged the latency and shortened the duration of each RopiCD50-induced seizure, improved the negative emotions revealed by both OF and EPM test, and inhibited p-ERK expression in the BLA and the CeA.
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Molecular neurobiology · Apr 2016
Meta AnalysisSerotonin Transporter Gene 5-HTTLPR Polymorphism as a Protective Factor Against the Progression of Post-Stroke Depression.
Polymorphisms in the 5-HTT and BDNF genes are shown to affect their function at the molecular and serum level. Prior work has tried to correlate the polymorphisms with post-stroke depression (PSD), the results nevertheless remain indefinitive. A plausible reason accounting for the uncertainty relates to the small sample of each published trial. ⋯ These results were reliable and stable based on related analyses. Taken together, 5-HTTLPR polymorphism of the 5-HTT gene seems to protect against the occurrence of PSD. Small sample size for the polymorphisms within 5-HTT and BDNF genes may have caused underestimated associations, and a larger study is required to further assess the relations.
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Molecular neurobiology · Apr 2016
(S)-Lacosamide Binding to Collapsin Response Mediator Protein 2 (CRMP2) Regulates CaV2.2 Activity by Subverting Its Phosphorylation by Cdk5.
The neuronal circuit remodels during development as well as in human neuropathologies such as epilepsy. Neurite outgrowth is an obligatory step in these events. We recently reported that alterations in the phosphorylation state of an axon specification/guidance protein, the collapsin response mediator protein 2 (CRMP2), play a major role in the activity-dependent regulation of neurite outgrowth. ⋯ Cross-linking experiments and analytical ultracentrifugation showed no effect of (S)-LCM on the oligomerization state of CRMP2. The increased association between Cdk5-phosphorylated CRMP2 and CaV2.2 was reduced by (S)-LCM in vitro and in vivo. This reduction translated into a decrease of calcium influx via CaV2.2 in (S)-LCM-treated neurons compared to controls. (S)-LCM, to our knowledge, is the first molecule described to directly inhibit CRMP2 phosphorylation and may be useful for delineating CRMP2-facilitated functions.
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Molecular neurobiology · Mar 2016
ASIC3 Is Required for Development of Fatigue-Induced Hyperalgesia.
An acute bout of exercise can exacerbate pain, hindering participation in regular exercise and daily activities. The mechanisms underlying pain in response to acute exercise are poorly understood. We hypothesized that proton accumulation during muscle fatigue activates acid-sensing ion channel 3 (ASIC3) on muscle nociceptors to produce hyperalgesia. ⋯ Genetic deletion of ASIC3 in primary afferents innervating muscle using an HSV-1 expressing microRNA (miRNA) to ASIC3 surprisingly had no effect on the development of the hyperalgesia. Muscle fatigue increased the number of macrophages in muscle, and removal of macrophages from muscle with clodronate liposomes prevented the development of fatigue-enhanced hyperalgesia. Thus, these data suggest that fatigue reduces pH in muscle that subsequently activates ASIC3 on macrophages to enhance hyperalgesia to muscle insult.