ObjectiveTo investigate the neuroprotective effects and mechanisms of selective histone deacetylases inhibitor MS-275 on rats after seizures. MethodsA total of 75 rats were randomly divided into 5 groups for treatment:control group,pilocarpine group, treatment group Ⅰ(administered with MS-275, 20mg/kg, once a day,intraperitoneally in 7 consecutive days), treatment group Ⅱ(administered with MS-275, 40mg/kg, once a day, intraperitoneally in 7 consecutive days), MS-275 pretreatment group. We used lithium and pilocarpin to induce seizures. Behaviors of rats in each group were observed. At 72 hours after seizures, Nissl staining and immunohistochemical were respectively used to evaluate the loss of neurons and histone acetylation levels of hippocampal CA1 and CA3 regions in each group. Escape latency in the control group, treatment group Ⅰ, treatment group Ⅱ and MS-275 pretreatment group were longer than pilocarpine group(P<0.05). ResultsCompared with the pilocarpine group, rats in MS-275 pretreatment group could delay pilocarpine-induced seizures and reduce mortality (P<0.05). Degree of neuronal loss and degeneration in both treatment group Ⅰ and treatment group Ⅱ were reduced compared with the pilocarpine group (P<0.05) and the level of histone acetylation in hippocampal CA1 and CA3 regions of the rats were increased compared with the pilocarpine group (P<0.05). ConclusionHDACs inhibitors MS-275 can improve the neuronal damage, histone deacetylation of rats' brain and rats cognitive decline, which can exert an neuroprotective effect on rats after seizures, whose mechanism may be related to its antiinflammatory effect.
It has been found that in biological studies, the simple linear superposition mathematical model cannot be used to express the feature mapping relationship from multiple activated grid cells' grid fields to a single place cell's place field output in the hippocampus of the cerebral cortex of rodents. To solve this problem, people introduced the Gauss distribution activation function into the area. We in this paper use the localization properties of the function to deal with the linear superposition output of grid cells' input and the connection weights between grid cells and place cells, which filters out the low activation rate place fields. We then obtained a single place cell field which is consistent with biological studies. Compared to the existing competitive learning algorithm place cell model, independent component analysis method place cell model, Bayesian positon reconstruction method place cell model, our experimental results showed that the model on the neurophysiological basis can not only express the feature mapping relationship between multiple activated grid cells grid fields and a single place cell's place field output in the hippocampus of the cerebral cortex of rodents, but also make the algorithm simpler, the required grid cells input less and the accuracy rate of the output of a single place field higher.
Alzheimer’s disease (AD) is a neurodegenerative disease characterized by cognitive impairment, with the predominant clinical diagnosis of spatial working memory (SWM) deficiency, which seriously affects the physical and mental health of patients. However, the current pharmacological therapies have unsatisfactory cure rates and other problems, so non-pharmacological physical therapies have gradually received widespread attention. Recently, a novel treatment using 40 Hz light flicker stimulation (40 Hz-LFS) to rescue the cognitive function of model animals with AD has made initial progress, but the neurophysiological mechanism remains unclear. Therefore, this paper will explore the potential neural mechanisms underlying the modulation of SWM by 40 Hz-LFS based on cross-frequency coupling (CFC). Ten adult Wistar rats were first subjected to acute LFS at frequencies of 20, 40, and 60 Hz. The entrainment effect of LFS with different frequency on neural oscillations in the hippocampus (HPC) and medial prefrontal cortex (mPFC) was analyzed. The results showed that acute 40 Hz-LFS was able to develop strong entrainment and significantly modulate the oscillation power of the low-frequency gamma (lγ) rhythms. The rats were then randomly divided into experimental and control groups of 5 rats each for a long-term 40 Hz-LFS (7 d). Their SWM function was assessed by a T-maze task, and the CFC changes in the HPC-mPFC circuit were analyzed by phase-amplitude coupling (PAC). The results showed that the behavioral performance of the experimental group was improved and the PAC of θ-lγ rhythm was enhanced, and the difference was statistically significant. The results of this paper suggested that the long-term 40 Hz-LFS effectively improved SWM function in rats, which may be attributed to its enhanced communication of different rhythmic oscillations in the relevant neural circuits. It is expected that the study in this paper will build a foundation for further research on the mechanism of 40 Hz-LFS to improve cognitive function and promote its clinical application in the future.
Febrile seizures (FS) are one of the most common neurological disorders in pediatrics, commonly seen in children from three months to five years of age. Most children with FS have a good prognosis, but some febrile convulsions progress to refractory epilepsy (RE). Epilepsy is a common chronic neurological disorder , and refractory epilepsy accounts for approximately one-third of epilepsies. The etiology of refractory epilepsy is currently complex and diverse, and its mechanisms are not fully understood. There are many pathophysiological changes that occur after febrile convulsions, such as inflammatory responses, changes in the blood-brain barrier, and oxidative stress, which can subsequently potentially lead to refractory epilepsy, and inflammation is always in tandem with all physiological changes as the main response. This article focuses on the pathogenesis of refractory epilepsy resulting from post-febrile convulsions.
This study aims to explore the diagnosis in patients with Alzheimer's disease (AD) based on magnetic resonance (MR) images, and to compare the differences of bilateral hippocampus in classification and recognition. MR images were obtained from 25 AD patients and 25 normal controls (NC) respectively. Three-dimensional texture features were extracted from bilateral hippocampus of each subject. The texture features that existed significant differences between AD and NC were used as the features in a classification procedure. Back propagation (BP) neural network model was built to classify AD patients from healthy controls. The classification accuracy of three methods, which were principal components analysis, linear discriminant analysis and non-linear discriminant analysis, was obtained and compared. The correlations between bilateral hippocampal texture parameters and Mini-Mental State Examination (MMSE) scores were calculated. The classification accuracy of nonlinear discriminant analysis with a neural network model was the highest, and the classification accuracy of right hippocampus was higher than that of the left. The bilateral hippocampal texture features were correlated to MMSE scores, and the relative of right hippocampus was higher than that of the left. The neural network model with three-dimensional texture features could recognize AD patients and NC, and right hippocampus might be more helpful to AD diagnosis.
ObjectiveThe research goal: to study the diagnostic value of T2-flair sequence of magnetic resonance imaging (MRI) in hippocampal sclerosis. MethodsThe clinical data of 135 patients with epilepsy caused by hippocampal sclerosis in the Epilepsy Center of Tianshui Third People's Hospital from March 2019 to December 2020 were analyzed retrospectively, studying the correlation between the changes of hippocampal sclerosis signal and the frequency of epileptic seizures in MRI T2-flair sequence multi axial scanning. ResultsThere were 109 cases of simple hippocampal sclerosis and 26 cases of hippocampal sclerosis with other lesions, including 8 cases of cavernous hemangioma, 9 cases of traumatic or infectious malacia, 2 cases of focal cortical dysplasia, 1 case of cerebral fissure malformation, 1 case of giant gyrus and 5 cases of perinatal brain injury. MRI features of hippocampal sclerosis were as follows: ① hippocampal volume increased slightly, structure blurred, and T2-flair showed slightly increased hippocampal signal in 15 cases, accounting for 11.11%; ② The hippocampal formation was fuzzy, T2-flair was punctate hyperintense, and the volume did not change in 17 cases (12.59%); ③ Hippocampal pyknosis into small lumps, T2-flair sequence showed high signal in 103 cases, accounting for 76.30%. Statistics showed that there was a correlation between hippocampal sclerosis signal and seizure frequency (χ2=94.94, P<0.05). The higher the hippocampal sclerosis signal, the more the seizure frequency. ConclusionMRI T2-flair sequence multi axial scanning can improve the diagnostic accuracy of hippocampal sclerosis. As the change of hippocampal sclerosis signal becomes more obvious, the trend of seizure frequency increases.
ObjectiveTo explore the dynamic expression changes of neuronal growth and differentiation-associated miR-124a and miR-9 in the process of epileptogenesis. MethodsEstablish the lithium-pilocarpine induced status epilepticus (SE) rat model. Animal behavior change induced by SE as well as in the period of chronic epilepsy was observed by naked-eye or video-recording. Major time points for the study were chosen at 1d, 7d, 14d and 28d post-SE, on which the post-SE rats were decapitated and their hippocampal specimens were obtained. Total RNA from each specimen was extracted and qPCR was exploited to detect miR-124a and miR-9 expression in the specimens. Statistical analysis was used to show the dynamic expressional changes of miR-124a and miR-9 in rat hippocampus at 1d, 7d, 14d and 28d post-SE during the process of epileptogenesis. ResultsCompared with normal rats, the expression level of miR-124a in rat hippocampus did not show a significant difference at 1d post-SE, but it had shown markedly differences at 7d, 14d and 28d post-SE(P < 0.05), with a declining trend. Compared with normal rats, the expression level of miR-9 had demonstrated significant differences at 1d, 7d, 14d and 28d post-SE(P < 0.05)with a generally increasing trend, although there was slight fluctuation of expressional up-regulation at 7d post-SE. ConclusionNeuronal growth and differentiation-associated miR-124a and miR-9 had shown dynamic changes of down-regulation or up-regulation in the process of epileptogenesis. It can be suspected that miR-124a and miR-9 take part in hippocampal neurogenesis post-SE and be involved in epileptogenesis process.