Early Intervention of Gastrodin Improved Motor Learning in Diabetic Rats Through Ameliorating Vascular Dysfunction.

The mechanism of cognitive dysfunction in diabetes is still unclear. Recently, studies have shown that the cerebellum is involved in cognition. Furthermore, diabetes-induced cerebellar alterations is related to vascular changes. Therefore, we aimed to explore the roles of vascular function in diabetes-induced cerebellar damage and motor learning deficits. Type 1 diabetes was induced by a single injection of streptozotocin in Sprague-Dawley rats. Motor learning was assessed by beam walk test and beam balance test. The pathological changes of the cerebellum were assessed by Hematoxylin and eosin staining and Nissl staining. Apoptosis was evaluated by anti-caspase-3 immunostaining. Protein expression was evaluated by western blotting and double immunofluorescence. Our results have shown that motor learning was impaired in diabetic rats, coupled with damaged Purkinje cells and decreased capillary density in the cerebellum. In addition, the protein expression of neuronal NOS, inducible NOS, endothelial NOS, total nitric oxide, vascular endothelial growth factor and its cognate receptor Flk-1 was decreased in the cerebellum. Gastrodin treatment ameliorated neuronal damage and restored protein expression of relevant factors. Arising from the above, it is suggested that vascular dysfunction and NO signaling deficits in the cerebellum may be the underlying mechanism of early manifestations of cognitive impairment in diabetes, which could be ameliorated by gastrodin intervention.

Genetic labeling reveals spatial and cellular expression pattern of neuregulin 1 in mouse brain.

BACKGROUND: Where the gene is expressed determines the function of the gene. Neuregulin 1 (Nrg1) encodes a tropic factor and is genetically linked with several neuropsychiatry diseases such as schizophrenia, bipolar disorder and depression. Nrg1 has broad functions ranging from regulating neurodevelopment to neurotransmission in the nervous system. However, the expression pattern of Nrg1 at the cellular and circuit levels in rodent brain is not full addressed. METHODS: Here we used CRISPR/Cas9 techniques to generate a knockin mouse line (Nrg1Cre/+) that expresses a P2A-Cre cassette right before the stop codon of Nrg1 gene. Since Cre recombinase and Nrg1 are expressed in the same types of cells in Nrg1Cre/+ mice, the Nrg1 expression pattern can be revealed through the Cre-reporting mice or adeno-associated virus (AAV) that express fluorescent proteins in a Cre-dependent way. Using unbiased stereology and fluorescence imaging, the cellular expression pattern of Nrg1 and axon projections of Nrg1-positive neurons were investigated. RESULTS: In the olfactory bulb (OB), Nrg1 is expressed in GABAergic interneurons including periglomerular (PG) and granule cells. In the cerebral cortex, Nrg1 is mainly expressed in the pyramidal neurons of superficial layers that mediate intercortical communications. In the striatum, Nrg1 is highly expressed in the Drd1-positive medium spiny neurons (MSNs) in the shell of nucleus accumbens (NAc) that project to substantia nigra pars reticulata (SNr). In the hippocampus, Nrg1 is mainly expressed in granule neurons in the dentate gyrus and pyramidal neurons in the subiculum. The Nrg1-expressing neurons in the subiculum project to retrosplenial granular cortex (RSG) and mammillary nucleus (MM). Nrg1 is highly expressed in the median eminence (ME) of hypothalamus and Purkinje cells in the cerebellum. CONCLUSIONS: Nrg1 is broadly expressed in mouse brain, mainly in neurons, but has unique expression patterns in different brain regions.

Overexpression of neuregulin 1 in GABAergic interneurons results in reversible cortical disinhibition.

Cortical disinhibition is a common feature of several neuropsychiatric diseases such as schizophrenia, autism and intellectual disabilities. However, the underlying mechanisms are not fully understood. To mimic increased expression of Nrg1, a schizophrenia susceptibility gene in GABAergic interneurons from patients with schizophrenia, we generated gtoNrg1 mice with overexpression of Nrg1 in GABAergic interneurons. gtoNrg1 mice showed cortical disinhibition at the cellular, synaptic, neural network and behavioral levels. We revealed that the intracellular domain of NRG1 interacts with the cytoplasmic loop 1 of Nav1.1, a sodium channel critical for the excitability of GABAergic interneurons, and inhibits Nav currents. Intriguingly, activation of GABAergic interneurons or restoring NRG1 expression in adulthood could rescue the hyperactivity and impaired social novelty in gtoNrg1 mice. These results identify mechanisms underlying cortical disinhibition related to schizophrenia and raise the possibility that restoration of NRG1 signaling and GABAergic function is beneficial in certain neuropsychiatric disorders.

Evaluation of the Chinese version of the swallowing screen in stroke patients with dysphagia.

OBJECTIVE: The purpose of this study was to validate a Chinese version of the modified Standardized Swallowing Assessment (SSA) instrument used by nurses in stroke patients with dysphagia and explore the feasibility of the simplified instrument. MATERIALS AND METHODS: This study involved a cross-sectional design. Nurses independently applied the modified SSA to 127 patients with stroke before a complete dysphagia evaluation conducted by a speech-language pathologist. Factor analysis of eight dysphagia variables in the modified SSA was performed to evaluate construct validity. The accuracy of the screening instrument was assessed through receiver operating characteristic (ROC) analysis. RESULTS: The comprehensive swallowing assessment revealed that 49.6% of the stroke patients had dysphagia. The modified SSA had an acceptable internal consistency coefficient. The inter-rater agreement between nurses using the modified SSA showed a Kappa coefficient of 0.509. All items had a communality loading of >0.5, and two factors accounted for 73.89% of the response variance. The area under the ROC curve was 0.79 (95% confidence interval: 0.71-0.87). The sensitivity and specificity derived for dysphagia detection were satisfactory according to the results obtained from the original 8-item and simplified 6-item scales (sensitivities = 82.50% and 81.00% and specificities = 59.40% and 64.10%, respectively; accuracy = 70.87% and 72.44%, respectively). CONCLUSION: This preliminary study suggests that the modified SSA is a potentially reliable and valid nurse-administered screening instrument for dysphagia detection in patients with stroke.

Genetic labeling reveals temporal and spatial expression pattern of D2 dopamine receptor in rat forebrain.

The D2 dopamine receptor (Drd2) is implicated in several brain disorders such as schizophrenia, Parkinson's disease, and drug addiction. Drd2 is also the primary target of both antipsychotics and Parkinson's disease medications. Although the expression pattern of Drd2 is relatively well known in mouse brain, the temporal and spatial distribution of Drd2 is lesser clear in rat brain due to the lack of Drd2 reporter rat lines. Here, we used CRISPR/Cas9 techniques to generate two knockin rat lines: Drd2::Cre and Rosa26::loxp-stop-loxp-tdTomato. By crossing these two lines, we produced Drd2 reporter rats expressing the fluorescence protein tdTomato under the control of the endogenous Drd2 promoter. Using fluorescence imaging and unbiased stereology, we revealed the cellular expression pattern of Drd2 in adult and postnatal rat forebrain. Strikingly, the Drd2 expression pattern differs between Drd2 reporter rats and Drd2 reporter mice generated by BAC transgene in prefrontal cortex and hippocampus. These results provide fundamental information needed for the study of Drd2 function in rat forebrain. The Drd2::Cre rats generated here may represent a useful tool to study the function of neuronal populations expressing Drd2.

Gastrodin Ameliorates Motor Learning Deficits Through Preserving Cerebellar Long-Term Depression Pathways in Diabetic Rats.

Cognitive dysfunction is a very severe consequence of diabetes, but the underlying causes are still unclear. Recently, the cerebellum was reported to play an important role in learning and memory. Since long-term depression (LTD) is a primary cellular mechanism for cerebellar motor learning, we aimed to explore the role of cerebellar LTD pathways in diabetic rats and the therapeutic effect of gastrodin. Diabetes was induced by a single injection of streptozotocin into adult Sprague-Dawley rats. Motor learning ability was assessed by a beam walk test. Pathological changes of the cerebellum were assessed by Hematoxylin-Eosin (HE) and Nissl staining. Cellular apoptosis was assessed by anti-caspase-3 immunostaining. Protein expression levels of LTD pathway-related factors, including GluR2, protein kinase C (PKC), NR2A, and nNOS, in the cerebellar cortex were evaluated by western blotting and double immunofluorescence. The NO concentration was measured. The cellular degeneration and the apoptosis of Purkinje cells were evident in the cerebellum of diabetic rats. Protein expression levels of GluR2 (NC9W: 1.26 ± 0.12; DM9W + S: 0.81 ± 0.07), PKC (NC9W: 1.66 ± 0.10; DM9W + S: 0.58 ± 0.19), NR2A (NC9W: 1.40 ± 0.05; DM9W + S: 0.63 ± 0.06), nNOS (NC9W: 1.26 ± 0.12; DM9W + S: 0.68 ± 0.04), and NO (NC9W: 135.61 ± 31.91; DM9W + S: 64.06 ± 24.01) in the cerebellum were significantly decreased in diabetic rats. Following gastrodin intervention, the outcome of motor learning ability was significantly improved (NC9W: 6.70 ± 3.31; DM9W + S: 20.47 ± 9.43; DM9W + G: 16.04 ± 7.10). In addition, degeneration and apoptosis were ameliorated, and this was coupled with the elevation of the protein expression of the abovementioned biomarkers. Arising from the above, we concluded that gastrodin may contribute to the improvement of motor learning by protecting the LTD pathways in Purkinje cells.

[Feasibility and clinical application of design about the hollowed titanium stick supporting the femoral head and preventing it from collapsing].

OBJECTIVE: To evaluate the feasibility and the clinical practicality of the design about the hollowed titanium stick supporting the femoral head and preventing it from collapsing. METHODS: From Jan.2003 to Jun.2007, 36 patients (46 hips) diagnosed as cystis degeneration of the femoral head were treated by surgical operation, including 20 males and 16 females with an average age of 40 years ranging from 18 to 56 years old, and the course of the disease was from 10 to 24 months (16 months on average). According to ARCO staging,there were 24 patients (34 hips) in NFH II, of which 11 hips were II a stage, 13 hips were II b stage and 10 hips were II c stage; there were 6 patients diagnosed as osteofibrous,4 patients as simple bone cyst and 2 patients as chondromyxoid fibroma. Under X-ray the percutaneous narrow core decompression and focus infection elimination were performed and supported the sclerotin under the cartilage with titanium stick. The patients were followed-up at the first, third, sixth, twelfth, twenty-fourth and thirty-sixth month after the operation. The clinical evaluation was done by X-ray and the indexes included stable, unstable and abortive. The data was analyzed by Fisher exact probility and the suviaval rate was analyzed by Kaplan-Meier suviaval curve using statistical soft ware SPSS13.5. RESULTS: There were no unstable or failure cases on each period from the 1st month to the 12th month after the operation, indicating that the supporting effect of the titanium stick was exact during 12 months after the operation. There were unstable and failure cases from the 12th month to the 24th month after the operation, which were mainly in stage NFH II c but the comparision of the stable rate in this period and 12 months after the operation had no obvious statistical differences (P>0.05) indicating that the supporting effect of the titanium stick was feasible during the stage. One of the unstable cases deteriorated and failed but there were no new unstable cases, both the stable rate and the unstable rate had no change and the failure rate rose on the 36th month after the operation. The compar- ision of the stable rate on each period after the operation had no obvious difference (P=0.197>0.05), which indicated that the supporting effect of the titanium stick was persistent. By the difference of the etiology the three-year survival rate of the relevant NFH II c pathological changes was the lowest-70% and the survival rate of the pathological changes induced by other etiological factors was 90.2%. CONCLUSION: The design about the hollowed titanium stick supporting the collapsed femoral head is feasible. Using the hollowed titanium stick to support the femoral head and prevent it from collapsing is pragmatic in the clinical and the effect is positive, however, when it comes to the NFH II c pathological changes, the choice should be made discreetly.