Acupuncture for ischemic stroke:cerebellar activation may be a central mechanism following Deqi

The needling sensation of Deqi during acupuncture is a key factor of influencing acupuncture outcome.Recent studies have mainly focused on the brain function effects of Deqi in a physiological state.Functional magnetic resonance imaging（f MRI）on the effects of acupuncture at Waiguan（SJ5）in pathological and physiological states is controversial.In this study,12 patients with ischemic stroke received acupuncture at Waiguan（SJ5）and simultaneously underwent f MRI scanning of the brain,with imaging data of the activated areas obtained.Based on the patient＇s sensation,imaging data were allocated to either the Deqi group or non-Deqi group.In the Deqi group,the activated/deactivated areas were the left superior temporal gyrus（BA39）/right anterior lobe of the cerebellum and left thalamus.In the non-Deqi group,the activated areas included the medial frontal gyrus of the right frontal lobe（BA11）,right limbic lobe（BA30,35）,and left frontal lobe（BA47）,while the only deactivated area was the right parietal lobe（BA40）.Compared with the non-Deqi group,the Deqi group exhibited marked activation of the right anterior lobe of the cerebellum and right limbic lobe（BA30）.These findings confirm that the clinical effect of Deqi during acupuncture is based on brain functional changes.Cerebellar activation may be one of the central mechanisms of acupuncture in the treatment of ischemic stroke.

Acupuncture at Waiguan(SJ5) and sham points influences activation of functional brain areas of ischemic stroke patients: a functional magnetic resonance imaging study

Most studies addressing the specificity of meridians and acupuncture points have focused mainly on the different neural effects of acupuncture at different points in healthy individuals. This study examined the effects of acupuncture on brain function in a pathological context. Sixteen patients with ischemic stroke were randomly assigned to true point group （true acupuncture at right Waiguan （SJ5）） and sham point group （sham acupuncture）. Results of functional magnetic resonance imaging revealed activation in right parietal lobe （Brodmann areas 7 and 19）, the right temporal lobe （Brodmann area 39）, the right limbic lobe （Brodmann area 23） and bilateral oc-cipital lobes （Brodmann area 18）. Furthermore, inhibition of bilateral frontal lobes （Brodmann area 4, 6, and 45）, right parietal lobe （Brodmann areas 1 and 5） and left temporal lobe （Brodmann area 21 ） were observed in the true point group. Activation in the precuneus of right parietal lobe （Brodmann area 7） and inhibition of the left superior frontal gyrus （Brodmann area 10） was observed in the sham group. Compared with sham acupuncture, acupuncture at Waiguan in stroke patients inhibited Brodmann area 5 on the healthy side. Results indicated that the altered specificity of sensation-associated cortex （Brodmann area 5） is possibly associated with a central mechanism of acupuncture at Waiguan for stroke patients.

Mash1 efficiently reprograms rat astrocytes into neurons

To date, it remains poorly understood whether astrocytes can be easily reprogrammed into neurons. Mashl and Brn2 have been previously shown to cooperate to reprogram fibroblasts into neurons. In this study, we examined astrocytes from 2-month-old Sprague-Dawley rats, and found that Brn2 was expressed, but Mashl was not detectable. Thus, we hypothesized that Mashl alone could be used to reprogram astrocytes into neurons. We transfected a recombinant MSCV-MASH1 plasmid into astrocytes for 72 hours, and saw that all cells expressed Mashl. One week later, we observed the changes in morphology of astrocytes, which showed typical neuro- nal characteristics. Moreover, β-tubulin expression levels were significantly higher in astrocytes expressing Mashl than in control cells. These results indicate that Mashl alone can reprogram astrocytes into neurons.

Somatosensory stimulation suppresses the excitability of pyramidal cells in the hippocampal CA1 region in rats

The hippocampal region of the brain is important for encoding environment inputs and memory formation. However, the underlying mechanisms are unclear. To investigate the behavior of indi-vidual neurons in response to somatosensory inputs in the hippocampal CA1 region, we recorded and analyzed changes in local ifeld potentials and the ifring rates of individual pyramidal cells and interneurons during tail clamping in urethane-anesthetized rats. We also explored the mechanisms underlying the neuronal responses. Somatosensory stimulation, in the form of tail clamping, chan-ged local ifeld potentials into theta rhythm-dominated waveforms, decreased the spike ifring of py-ramidal cells, and increased interneuron ifring. In addition, somatosensory stimulation attenuated orthodromic-evoked population spikes. These results suggest that somatosensory stimulation sup-presses the excitability of pyramidal cells in the hippocampal CA1 region. Increased inhibition by local interneurons might underlie this effect. These ifndings provide insight into the mechanisms of signal processing in the hippocampus and suggest that sensory stimulation might have thera-peutic potential for brain disorders associated with neuronal hyperexcitability.

Does the ratio of the carpal tunnel inlet and outlet cross-sectional areas in the median nerve reflect carpal tunnel syndrome severity?

Although ultrasound measurements have been used in previous studies on carpal tunnel syndrome to visualize injury to the median nerve, whether such ultrasound data can indicate the severity of carpal tunnel syndrome remains controversial. The cross-sectional areas of the median nerve at the tunnel inlet and outlet can show swelling and compression of the nerve at the carpal. We hypothesized that the ratio of the cross-sectional areas of the median nerve at the carpal tunnel inlet to outlet accurately reflects the severity of carpal tunnel syndrome. To test this, high-resolution ultrasound with a linear array transducer at 5–17 MHz was used to assess 77 patients with carpal tunnel syndrome. The results showed that the cut-off point for the inlet-to-outlet ratio was 1.14. Significant differences in the inlet-to-outlet ratio were found among patients with mild, moderate, and severe carpal tunnel syndrome. The cut-off point in the ratio of cross-sectional areas of the median nerve was 1.29 between mild and more severe（moderate and severe） carpal tunnel syndrome patients with 64.7% sensitivity and 72.7% specificity. The cut-off point in the ratio of cross-sectional areas of the median nerve was 1.52 between the moderate and severe carpal tunnel syndrome patients with 80.0% sensitivity and 64.7% specificity. These results suggest that the inlet-to-outlet ratio reflected the severity of carpal tunnel syndrome.

Seven Research Projects Sponsored by the 973 Program and the Major Research Plan

China＇s Ministry of Science and Technology recently announced approval of China＇s National Basic Research Program （the 973 Program） and the Major Research Plan projects in 2008. Five Tsinghua research projects will be sponsored by the 973 Program and two by the Major Research Plan. Seven professors were appointed as chief scientists for the projects. Tsinghua has undertaken 28 projects since the 973 Program＇s inception involving 28 chief scientists and eight Major Research Plan projects involving eight chief scientists. Tsinghua is one of the country＇s leading institutions for supervision and conduct of the 973 Program projects.