While multiple step saccades(MSS)are occasionally reported in the healthy population,they are more evident in patients with Parkinson’s disease(PD).Therefore,MSS has been suggested as a biological marker for the diag...While multiple step saccades(MSS)are occasionally reported in the healthy population,they are more evident in patients with Parkinson’s disease(PD).Therefore,MSS has been suggested as a biological marker for the diagnosis of PD.However,the lack of clarity on the neural mechanism underlying the generation of MSS largely impedes their application in the clinic.We have proposed recently that MSS are triggered by the discrepancy between desired and executed saccades.Accordingly,brain regions involved in saccadic planning and execution might play a role in the generation of MSS.To test this hypothesis,we explored the role of the prefrontal(PFC)and posterior parietal cortex(PPC)in generating MSS by conducting two experiments:electroencephalographic recording and single-pulse transcranial magnetic stimulation in the PFC or PPC of humans while participants were performing a gap saccade task.We found that the PFC and PPC are involved in the generation of MSS.展开更多
Real-time functional magnetic resonance imaging (rtfMRI) technology has been widely used to train subjects to actively regulate the activity of specific brain regions. Although many previous studies have demonstrated ...Real-time functional magnetic resonance imaging (rtfMRI) technology has been widely used to train subjects to actively regulate the activity of specific brain regions. Although many previous studies have demonstrated that neurofeedback training alters the functional connectivity between brain regions in the task state and resting state, it is unclear how the regulation of the key hub of the default mode network (DMN) affects the topological properties of the resting-state brain network. The current study aimed to investigate what topological changes would occur in the large-scale intrinsic organization of the resting state after the real-time down-regulation of the posterior cingulate cortex (PCC). The results indicated that the down-regulation of the PCC in the DMN reduced the functional connectivity of the PCC with the nodes outside of the DMN and reduced functional connectivity between the superior medial frontal gyrus (SFGmed) and parahippocampal gyrus (PHG) in the experimental group. Moreover, the nodal graph properties of the SFGmed were reduced, while that of the PHG showed the opposite alteration after the down-regulation of the PCC. These findings possibly suggest that the regulation of the key hub of the DMN, the PCC, mainly changed the information transfer of the SFGmed and PHG.展开更多
Major depressive disorder (MDD) is a severe, disabling pathology characterized, in addition to affective, cognitive and motor symptoms, by self-focused attention and rumination. During recursive self-focused processes...Major depressive disorder (MDD) is a severe, disabling pathology characterized, in addition to affective, cognitive and motor symptoms, by self-focused attention and rumination. During recursive self-focused processes and rumination, the posterior cingulate cortex (PCC) is activated. In vivo proton magnetic resonance spectroscopy (MRS) is a noninvasive imaging technique that can directly assess living biochemistry in localized brain regions. The aim of this study, therefore, was to use 1H-MRS as a means of analyzing brain metabolites in the PCC of a group of first-episode, unmedicated MDD patients. PCC metabolite levels were analyzed at 3-T in a single voxel located bilaterally over the PCC in 7 patients diagnosed for the first time with MDD and with no previous pharmacological treatment, as well as in 9 control subjects. Differences in metabolite levels between groups were compared using independent t-tests. Myo-inositol was significantly higher, and NAA + NAAG/Cr significantly lower, in MDD patients than in controls. The other brain metabolites showed no statistical differences. The present results suggest that alterations in PCC metabolite levels are likely involved in MDD pathophysiology, and may help to improve our understanding of MDD and the role of the PCC in some symptoms of depression.展开更多
AIM:To describe a quick,cost-effective alternative to using a scraper to remove the residual posterior vitreous cortex and create an inner limiting membrane(ILM)flap during vitrectomy.METHODS:The surgical technique an...AIM:To describe a quick,cost-effective alternative to using a scraper to remove the residual posterior vitreous cortex and create an inner limiting membrane(ILM)flap during vitrectomy.METHODS:The surgical technique and a retrospective interventional single-center series of cases were described.A hook was made on the tip of a conventional syringe needle(outer diameter,0.6 mm;23 gauge)by bending the needle against a plate.We used this hook to remove the residual posterior vitreous cortex and create an ILM flap during vitrectomy.The efficacy and safety of using this instrument in ophthalmological procedures for a variety of vitreoretinal disorders were evaluated.RESULTS:The hook was effective for removing focal or diffuse residual posterior vitreous cortex in eyes with rhegmatogenous retinal detachment,proliferative diabetic retinopathy,and pathological myopia.It was also successfully used to make a free edge of the ILM and help strip the epiretinal membrane.There were no serious complications associated with using the hook in delicate ophthalmological procedures.CONCLUSION:The hook,made by bending a conventional needle,is a simple and cost-effective instrument for removing residual posterior vitreous vortex and to create epiretinal and ILM flaps during vitrectomy in eyes with various vitreoretinal diseases.展开更多
Background:Performing an anti-saccade relies on two mechanisms:(I)inhibiting an automatic saccade to a target,and(II)generating,instead,a voluntary saccade to a location other than this visual target.It remains unclea...Background:Performing an anti-saccade relies on two mechanisms:(I)inhibiting an automatic saccade to a target,and(II)generating,instead,a voluntary saccade to a location other than this visual target.It remains unclear where and how these two processes are implemented to ensure the production of correct anti-saccades.Previous research in optic ataxia has implicated the posterior parietal cortex(PPC)in anti-pointing,implying a possible role of the PPC in anti-saccade production.Methods:Here,we tested how three patients with unilateral or bilateral damage to the PPC,as well as six neurologically intact controls,perform different types of anti-saccade:classic anti-saccades(180°rotation)or mirror saccades(90°rotation)across and within hemi-fields.Results:We showed that PPC damaged patients were impaired in anti-saccade production for their contralesional visual fields.This was reflected in a longer period of erroneous pro-saccades,longer latencies associated with correct anti-saccades to the contralesional visual field and more imprecise anti-saccades.Conclusions:Our results thus suggest that PPC damage results in delayed and prolonged competing saccade planning processes between two locations(i.e.,visual target and saccade goal location).Taken together,our results provide evidence for a crucial role of the PPC in parallel mechanisms underlying anti-saccade performance.展开更多
Motor timing is an important part of sensorimotor control. Previous studies have shown that beta oscillations embody the process of temporal perception in explicit timing tasks. In contrast, studies focusing on beta o...Motor timing is an important part of sensorimotor control. Previous studies have shown that beta oscillations embody the process of temporal perception in explicit timing tasks. In contrast, studies focusing on beta oscillations in implicit timing tasks are lacking. In this study, we set up an implicit motor timing task and found a modulation pattern of beta oscillations with temporal perception during movement preparation. We trained two macaques in a repetitive visually-guided reach-to-grasp task with different holding intervals. Spikes and local field potentials were recorded from microelectrode arrays in the primary motor cortex, primary somatosensory cortex, and posterior parietal cortex. We analyzed the association between beta oscillations and temporal interval in fixedduration experiments(500 ms as the Short Group and1500 ms as the Long Group) and random-duration experiments(500 ms to 1500 ms). The results showed that the peak beta frequencies in both experiments ranged from15 Hz to 25 Hz. The beta power was higher during the hold period than the movement(reach and grasp) period.Further, in the fixed-duration experiments, the mean poweras well as the maximum rate of change of beta power in the first 300 ms were higher in the Short Group than in the Long Group when aligned with the Center Hit event. In contrast, in the random-duration experiments, the corresponding values showed no statistical differences among groups. The peak latency of beta power was shorter in the Short Group than in the Long Group in the fixed-duration experiments, while no consistent modulation pattern was found in the random-duration experiments. These results indicate that beta oscillations can modulate with temporal interval in their power mode. The synchronization period of beta power could reflect the cognitive set maintaining working memory of the temporal structure and attention.展开更多
A number of studies have indicated that disor- ders of consciousness result from multifocal injuries as well as from the impaired functional and anatomical connectivity between various anterior forebrain regions. Howe...A number of studies have indicated that disor- ders of consciousness result from multifocal injuries as well as from the impaired functional and anatomical connectivity between various anterior forebrain regions. However, the specific causal mechanism linking these regions remains unclear. In this study, we used spectral dynamic causal modeling to assess how the effective connections （ECs） between various regions differ between individuals. Next, we used connectome-based predictive modeling to evaluate the performance of the ECs in predicting the clinical scores of DOC patients. We found increased ECs from the striatum to the globus pallidus as well as from the globus pallidus to the posterior cingulate cortex, and decreased ECs from the globus pallidus to the thalamus and from the medial prefrontal cortex to the striatum in DOC patients as compared to healthy controls. Prediction of the patients＇ outcome was effective using the negative ECs as features. In summary, the present study highlights a key role of the thalamo-basal ganglia-cortical loop in DOCs and supports the anterior forebrain mesocircuit hypothesis. Furthermore, EC could be potentially used to assess the consciousness level.展开更多
目的 观察自体乳突皮质骨粉行乳突填塞重建外耳道后壁的临床疗效。方法 43例慢性化脓性中耳炎或中耳胆脂瘤患者行乳突开放＋鼓室成形术后,应用自体乳突皮质骨粉填塞乳突术腔行外耳道后壁重建术,加耳甲腔成形术。结果 术后随访时间3~22个...目的 观察自体乳突皮质骨粉行乳突填塞重建外耳道后壁的临床疗效。方法 43例慢性化脓性中耳炎或中耳胆脂瘤患者行乳突开放＋鼓室成形术后,应用自体乳突皮质骨粉填塞乳突术腔行外耳道后壁重建术,加耳甲腔成形术。结果 术后随访时间3~22个月,平均13.4个月;所有病例均干耳,术后干耳时间为20-56 d,平均为31.7 d。言语频率（0.5、1、2 k Hz）平均纯音听力（pure tone average,PTA）气导由术前55.0±6.2 d B提高到术后34.0±3.2 d B,骨导由术前28.1±4.4 d B提高到术后21.5±4.1 d B,气骨导差（air-bone gap,ABG）由术前26.8±7.8 d B缩小到12.5±4.1 d B,术后听力提高成功率（术后PTA-ABG≤20 d B）为74.4%（32/43例）。除4例出现填塞骨粉感染、散落外,术后所有患者外耳道形态接近正常解剖结构,鼓膜形态正常,无再穿孔及内陷袋形成,外耳道后壁重建成功率为90.7%（39/43例）。结论 中耳乳突开放术后应用自体乳突皮质骨粉填塞乳突术腔行外耳道后壁重建术,是缩小乳突术腔,获得近似正常的外耳道解剖形态结构的有效方法。展开更多
基金supported by North Sichuan Medical College(CBY23-QDA14)the National Natural Science Foundation of China(32030045 and 82071454)+4 种基金Nanchong Federation of Social Science Associations(NC24C145)the Sichuan Science and Technology Program(2024NSFSC2017,2024ZYD0086)the Sichuan Students'Platform for Innovation Training Program(S202410634035)the Health Commission of Sichuan Province(24WSXT044)funded by the Open Research Fund of the State Key Laboratory of Cognitive Neuroscience and Learning(CNLYB2403).
文摘While multiple step saccades(MSS)are occasionally reported in the healthy population,they are more evident in patients with Parkinson’s disease(PD).Therefore,MSS has been suggested as a biological marker for the diagnosis of PD.However,the lack of clarity on the neural mechanism underlying the generation of MSS largely impedes their application in the clinic.We have proposed recently that MSS are triggered by the discrepancy between desired and executed saccades.Accordingly,brain regions involved in saccadic planning and execution might play a role in the generation of MSS.To test this hypothesis,we explored the role of the prefrontal(PFC)and posterior parietal cortex(PPC)in generating MSS by conducting two experiments:electroencephalographic recording and single-pulse transcranial magnetic stimulation in the PFC or PPC of humans while participants were performing a gap saccade task.We found that the PFC and PPC are involved in the generation of MSS.
文摘Real-time functional magnetic resonance imaging (rtfMRI) technology has been widely used to train subjects to actively regulate the activity of specific brain regions. Although many previous studies have demonstrated that neurofeedback training alters the functional connectivity between brain regions in the task state and resting state, it is unclear how the regulation of the key hub of the default mode network (DMN) affects the topological properties of the resting-state brain network. The current study aimed to investigate what topological changes would occur in the large-scale intrinsic organization of the resting state after the real-time down-regulation of the posterior cingulate cortex (PCC). The results indicated that the down-regulation of the PCC in the DMN reduced the functional connectivity of the PCC with the nodes outside of the DMN and reduced functional connectivity between the superior medial frontal gyrus (SFGmed) and parahippocampal gyrus (PHG) in the experimental group. Moreover, the nodal graph properties of the SFGmed were reduced, while that of the PHG showed the opposite alteration after the down-regulation of the PCC. These findings possibly suggest that the regulation of the key hub of the DMN, the PCC, mainly changed the information transfer of the SFGmed and PHG.
基金Lily M.Granados-Dominguez received a grant from CONACYT for graduate studies.
文摘Major depressive disorder (MDD) is a severe, disabling pathology characterized, in addition to affective, cognitive and motor symptoms, by self-focused attention and rumination. During recursive self-focused processes and rumination, the posterior cingulate cortex (PCC) is activated. In vivo proton magnetic resonance spectroscopy (MRS) is a noninvasive imaging technique that can directly assess living biochemistry in localized brain regions. The aim of this study, therefore, was to use 1H-MRS as a means of analyzing brain metabolites in the PCC of a group of first-episode, unmedicated MDD patients. PCC metabolite levels were analyzed at 3-T in a single voxel located bilaterally over the PCC in 7 patients diagnosed for the first time with MDD and with no previous pharmacological treatment, as well as in 9 control subjects. Differences in metabolite levels between groups were compared using independent t-tests. Myo-inositol was significantly higher, and NAA + NAAG/Cr significantly lower, in MDD patients than in controls. The other brain metabolites showed no statistical differences. The present results suggest that alterations in PCC metabolite levels are likely involved in MDD pathophysiology, and may help to improve our understanding of MDD and the role of the PCC in some symptoms of depression.
基金Supported by the National Natural Science Foundation of China(No.81770944,No.81800846)Shanghai Hospital Development Center(No.SHDC2020CR2041B)。
文摘AIM:To describe a quick,cost-effective alternative to using a scraper to remove the residual posterior vitreous cortex and create an inner limiting membrane(ILM)flap during vitrectomy.METHODS:The surgical technique and a retrospective interventional single-center series of cases were described.A hook was made on the tip of a conventional syringe needle(outer diameter,0.6 mm;23 gauge)by bending the needle against a plate.We used this hook to remove the residual posterior vitreous cortex and create an ILM flap during vitrectomy.The efficacy and safety of using this instrument in ophthalmological procedures for a variety of vitreoretinal disorders were evaluated.RESULTS:The hook was effective for removing focal or diffuse residual posterior vitreous cortex in eyes with rhegmatogenous retinal detachment,proliferative diabetic retinopathy,and pathological myopia.It was also successfully used to make a free edge of the ILM and help strip the epiretinal membrane.There were no serious complications associated with using the hook in delicate ophthalmological procedures.CONCLUSION:The hook,made by bending a conventional needle,is a simple and cost-effective instrument for removing residual posterior vitreous vortex and to create epiretinal and ILM flaps during vitrectomy in eyes with various vitreoretinal diseases.
文摘Background:Performing an anti-saccade relies on two mechanisms:(I)inhibiting an automatic saccade to a target,and(II)generating,instead,a voluntary saccade to a location other than this visual target.It remains unclear where and how these two processes are implemented to ensure the production of correct anti-saccades.Previous research in optic ataxia has implicated the posterior parietal cortex(PPC)in anti-pointing,implying a possible role of the PPC in anti-saccade production.Methods:Here,we tested how three patients with unilateral or bilateral damage to the PPC,as well as six neurologically intact controls,perform different types of anti-saccade:classic anti-saccades(180°rotation)or mirror saccades(90°rotation)across and within hemi-fields.Results:We showed that PPC damaged patients were impaired in anti-saccade production for their contralesional visual fields.This was reflected in a longer period of erroneous pro-saccades,longer latencies associated with correct anti-saccades to the contralesional visual field and more imprecise anti-saccades.Conclusions:Our results thus suggest that PPC damage results in delayed and prolonged competing saccade planning processes between two locations(i.e.,visual target and saccade goal location).Taken together,our results provide evidence for a crucial role of the PPC in parallel mechanisms underlying anti-saccade performance.
基金the International Cooperation and Exchange of the National Natural Science Foundation of China (31320103914)the General Program of the National Natural Science Foundation of China (31370987)+2 种基金the National Natural Science Foundation of China for Outstanding Young Scholars (81622027)the Beijing Nova Program of China (2016B615)the National Basic Research Development Program of China (2017YFA0106100)
文摘Motor timing is an important part of sensorimotor control. Previous studies have shown that beta oscillations embody the process of temporal perception in explicit timing tasks. In contrast, studies focusing on beta oscillations in implicit timing tasks are lacking. In this study, we set up an implicit motor timing task and found a modulation pattern of beta oscillations with temporal perception during movement preparation. We trained two macaques in a repetitive visually-guided reach-to-grasp task with different holding intervals. Spikes and local field potentials were recorded from microelectrode arrays in the primary motor cortex, primary somatosensory cortex, and posterior parietal cortex. We analyzed the association between beta oscillations and temporal interval in fixedduration experiments(500 ms as the Short Group and1500 ms as the Long Group) and random-duration experiments(500 ms to 1500 ms). The results showed that the peak beta frequencies in both experiments ranged from15 Hz to 25 Hz. The beta power was higher during the hold period than the movement(reach and grasp) period.Further, in the fixed-duration experiments, the mean poweras well as the maximum rate of change of beta power in the first 300 ms were higher in the Short Group than in the Long Group when aligned with the Center Hit event. In contrast, in the random-duration experiments, the corresponding values showed no statistical differences among groups. The peak latency of beta power was shorter in the Short Group than in the Long Group in the fixed-duration experiments, while no consistent modulation pattern was found in the random-duration experiments. These results indicate that beta oscillations can modulate with temporal interval in their power mode. The synchronization period of beta power could reflect the cognitive set maintaining working memory of the temporal structure and attention.
基金supported by National Natural Science Foundation of China (81471654, 81428013, 81371535, and 81271548)the Natural Science Foundation of Guangdong Province, China (2015A030313609)+1 种基金Planned Science and Technology Project of Guangzhou Municipality, China (20160402007 and 201604020184)the Innovation Project of The Graduate School of South China Normal University
文摘A number of studies have indicated that disor- ders of consciousness result from multifocal injuries as well as from the impaired functional and anatomical connectivity between various anterior forebrain regions. However, the specific causal mechanism linking these regions remains unclear. In this study, we used spectral dynamic causal modeling to assess how the effective connections （ECs） between various regions differ between individuals. Next, we used connectome-based predictive modeling to evaluate the performance of the ECs in predicting the clinical scores of DOC patients. We found increased ECs from the striatum to the globus pallidus as well as from the globus pallidus to the posterior cingulate cortex, and decreased ECs from the globus pallidus to the thalamus and from the medial prefrontal cortex to the striatum in DOC patients as compared to healthy controls. Prediction of the patients＇ outcome was effective using the negative ECs as features. In summary, the present study highlights a key role of the thalamo-basal ganglia-cortical loop in DOCs and supports the anterior forebrain mesocircuit hypothesis. Furthermore, EC could be potentially used to assess the consciousness level.
文摘目的 观察自体乳突皮质骨粉行乳突填塞重建外耳道后壁的临床疗效。方法 43例慢性化脓性中耳炎或中耳胆脂瘤患者行乳突开放＋鼓室成形术后,应用自体乳突皮质骨粉填塞乳突术腔行外耳道后壁重建术,加耳甲腔成形术。结果 术后随访时间3~22个月,平均13.4个月;所有病例均干耳,术后干耳时间为20-56 d,平均为31.7 d。言语频率（0.5、1、2 k Hz）平均纯音听力（pure tone average,PTA）气导由术前55.0±6.2 d B提高到术后34.0±3.2 d B,骨导由术前28.1±4.4 d B提高到术后21.5±4.1 d B,气骨导差（air-bone gap,ABG）由术前26.8±7.8 d B缩小到12.5±4.1 d B,术后听力提高成功率（术后PTA-ABG≤20 d B）为74.4%（32/43例）。除4例出现填塞骨粉感染、散落外,术后所有患者外耳道形态接近正常解剖结构,鼓膜形态正常,无再穿孔及内陷袋形成,外耳道后壁重建成功率为90.7%（39/43例）。结论 中耳乳突开放术后应用自体乳突皮质骨粉填塞乳突术腔行外耳道后壁重建术,是缩小乳突术腔,获得近似正常的外耳道解剖形态结构的有效方法。
