This paper aims to assist the individual clinical diagnosis of children with attention-deficit/hyperactivity disorder using electroencephalogram signal detection method. Firstly, in our experiments, we obtained and studied the electroencephalogram signals from fourteen attention-deficit/hyperactivity disorder children and sixteen typically developing children during the classic interference control task of Simon-spatial Stroop, and we completed electroencephalogram data preprocessing including filtering, segmentation, removal of artifacts and so on. Secondly, we selected the subset electroencephalogram electrodes using principal component analysis (PCA) method, and we collected the common channels of the optimal electrodes which occurrence rates were more than 90% in each kind of stimulation. We then extracted the latency (200~450 ms) mean amplitude features of the common electrodes. Finally, we used the k-nearest neighbor (KNN) classifier based on Euclidean distance and the support vector machine (SVM) classifier based on radial basis kernel function to classify. From the experiment, at the same kind of interference control task, the attention-deficit/hyperactivity disorder children showed lower correct response rates and longer reaction time. The N2 emerged in prefrontal cortex while P2 presented in the inferior parietal area when all kinds of stimuli demonstrated. Meanwhile, the children with attention-deficit/hyperactivity disorder exhibited markedly reduced N2 and P2 amplitude compared to typically developing children. KNN resulted in better classification accuracy than SVM classifier, and the best classification rate was 89.29% in StI task. The results showed that the electroencephalogram signals were different in the brain regions of prefrontal cortex and inferior parietal cortex between attention-deficit/hyperactivity disorder and typically developing children during the interference control task, which provided a scientific basis for the clinical diagnosis of attention-deficit/hyperactivity disorder individuals.
ObjectiveTo establish the system of isolation, cultivation, and identification of the neural stem cells (NSCs) from subventricular zone (SVZ) of neonatal mice so as to seek for the appropriate seed cells for potential therapeutic interventions of neurological disorders. MethodsNSCs were isolated enzymatically and mechanically from SVZ of neonatal mice and cultured. The cellular morphology was observed by inverted microscopy. Immunocytochemical stainings of anti-Nestin and anti-SOX-2 were used to identify NSCs of passage 3. To study the differentiation of NSCs, NSCs were plated into 24-wells in the medium supplemented without epidermal growth factor (EGF) and basic fibroblastic growth factor (bFGF) for 3 or 7 days. To compare the differentiation and proliferation potential of NSCs with different cultivation time, the BrdU pulse-labeling method and MTT test were used. To identify neurons and astrocytes, the anti-β-tubulin Ⅲ (Tuj-1) and anti-glial fibrillary acidic protein (GFAP) staining were used. ResultsThe cells of the SVZ can be isolated and cultured in vitro, and these cells began to form neurospheres after cultured for 3 days at primary passage. While cultured for 7 days, these cells formed more neurospheres, and the volume of the neurospheres became bigger than neurospheres cultured for 3 days. In addition, after cultured for 7 days, the phenomena of fusion of neurospheres and adherent differentiation of neurospheres were observed under inverted microscope. These cells were provided with the typical phenotype of NSCs. The immunofluorescence staining results revealed that these cells showed positive immunoreactivity to Nestin and SOX-2. During the 4 hours BrdU pulse, the number of proliferated NSCs cultured for 3 days (75.817±2.961) was significantly higher than that of NSCs cultured for 7 days (56.600±4.881) (t=3.366, P=0.028). The results of MTT assay revealed that the absorbance (A) value of NSCs cultured for 3 days (0.478±0.025) was significantly higher than that of NSCs which were cultured for 7 days (0.366±0.032)(t=2.752, P=0.011). After cultivated without EGF and bFGF, the percentage of Tuj-1 and GFAP positive cells in NSCs was 23.1%±3.7% and 23.7%±3.8% for 3 days and was 40.1%±3.6% and 37.1%±4.5% for 7 days, respectively, all showing significant differences (t=3.285, P=0.030; t=3.930, P=0.017). ConclusionThe NSCs from SVZ of neonatal mice have potentials of self-renewal and multipotential differentiation in vitro. With different cultivation time, the potentials of proliferation and differentiation of NSCs are different.