Structural changes in pyramidal cell dendrites and synapses in the unaffected side of the sensorimotor cortex following transcranial magnetic stimulation and rehabilitation training in a rat model of focal cerebral infarct

Very little is known about the effects of transcranial magnetic stimulation and rehabilitation training on pyramidal cell dendrites and synapses of the contralateral, unaffected sensorimotor cortex in a rat model of focal cerebral infarct. The present study was designed to explore the mechanisms underlying improved motor function via transcranial magnetic stimulation and rehabilitation training following cerebral infarction. Results showed that rehabilitation training or transcranial magnetic stimulation alone reduced neurological impairment in rats following cerebral infarction, as well as significantly increased synaptic curvatures and post-synaptic density in the non-injured cerebral hemisphere sensorimotor cortex and narrowed the synapse cleft width. In addition, the percentage of perforated synapses increased. The combination of transcranial magnetic stimulation and rehabilitation resulted in significantly increased total dendritic length, dendritic branching points, and dendritic density in layer V pyramidal cells of the non-injured cerebral hemisphere motor cortex. These results demonstrated that transcranial magnetic stimulation and rehabilitation training altered structural parameters of pyramidal cell dendrites and synapses in the non-injured cerebral hemisphere sensorimotor cortex, thereby improving the ability to compensate for neurological functions in rats following cerebral infarction.

Non-concomitant cortical structural and functional alterations in sensorimotor areas following incomplete spinal cord injury

Brain plasticity, including anatomical changes and functional reorganization, is the physiological basis of functional recovery after spinal cord injury（SCI）. The correlation between brain anatomical changes and functional reorganization after SCI is unclear. This study aimed to explore whether alterations of cortical structure and network function are concomitant in sensorimotor areas after incomplete SCI. Eighteen patients with incomplete SCI（mean age 40.94 ± 14.10 years old; male：female, 7：11） and 18 healthy subjects（37.33 ± 11.79 years old; male：female, 7：11） were studied by resting state functional magnetic resonance imaging. Gray matter volume（GMV） and functional connectivity were used to evaluate cortical structure and network function, respectively. There was no significant alteration of GMV in sensorimotor areas in patients with incomplete SCI compared with healthy subjects. Intra-hemispheric functional connectivity between left primary somatosensory cortex（BA1） and left primary motor cortex（BA4）, and left BA1 and left somatosensory association cortex（BA5） was decreased, as well as inter-hemispheric functional connectivity between left BA1 and right BA4, left BA1 and right BA5, and left BA4 and right BA5 in patients with SCI. Functional connectivity between both BA4 areas was also decreased. The decreased functional connectivity between the left BA1 and the right BA4 positively correlated with American Spinal Injury Association sensory score in SCI patients. The results indicate that alterations of cortical anatomical structure and network functional connectivity in sensorimotor areas were non-concomitant in patients with incomplete SCI, indicating the network functional changes in sensorimotor areas may not be dependent on anatomic structure. The strength of functional connectivity within sensorimotor areas could serve as a potential imaging biomarker for assessment and prediction of sensory function in patients with incomplete SCI. This trial was registered with the Chinese Clinical Trial Registry（registration number： Chi CTR-ROC-17013566）.

Changes in sensorimotor regions of the cerebral cortex in congenital amusia:a case-control study

Perceiving pitch is a central function of the human auditory system;congenital amusia is a disorder of pitch perception.The underlying neural mechanisms of congenital amusia have been actively discussed.However,little attention has been paid to the changes in the motor rain within congenital amusia.In this case-control study,17 participants with congenital amusia and 14 healthy controls underwent functional magnetic resonance imaging while resting with their eyes closed.A voxel-based degree centrality method was used to identify abnormal functional network centrality by comparing degree centrality values between the congenital amusia group and the healthy control group.We found decreased degree centrality values in the right primary sensorimotor areas in participants with congenital amusia relative to controls,indicating potentially decreased centrality of the corresponding brain regions in the auditory-sensory motor feedback network.We found a significant positive correlation between the degree centrality values and the Montreal Battery of Evaluation of Amusia scores.In conclusion,our study identified novel,hitherto undiscussed candidate brain regions that may partly contribute to or be modulated by congenital amusia.Our evidence supports the view that sensorimotor coupling plays an important role in memory and musical discrimination.The study was approved by the Ethics Committee of the Second Xiangya Hospital,Central South University,China(No.WDX20180101GZ01)on February 9,2019.

Aberrant Light-Induced Depression is Associated with Impaired Sensorimotor Gating in Mice

Mice subjected to an irregular light-dark cycle are known to lose their capacity to synchronize their behavioral rhythm to environmental light, and to show endophenotypes related to depressive disorders. Here we observed that a susceptible strain of mice (C3H/HeJ) subjected to an irregular 3.5 hr:3.5 hr light-dark cycle showed an enhanced acoustic startle reflex and deficits in prepulse inhibition. As impaired sensorimotor gating is associated with the onset of a variety of mental disorders such as schizophrenia and major depressive disorder, irregular environmental light without circadian photo-entrainment may cause stress that has the potential to be involved in humans’ susceptibility to neuropsychiatric abnormalities.

Activation of cerebral Ras-related C3 botulinum toxin substrate(Rac) 1 promotes post-ischemic stroke functional recovery in aged mice

Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain unclear.It is well-recognized that age is the most important independent predictor of poor outcomes after stroke as older patients show poorer functional outcomes following stroke.Mounting evidence suggests that axonal regeneration and angiogenesis,the major forms of brain plasticity responsible for post-stroke recovery,diminished with advanced age.Previous studies suggest that Ras-related C3 botulinum toxin substrate(Rac)1 enhances stroke recovery as activation of Rac1 improved behavior recovery in a young mice stroke model.Here,we investigated the role of Rac1 signaling in long-term functional recovery and brain plasticity in an aged(male,18 to 22 months old C57BL/6J)brain after ischemic stroke.We found that as mice aged,Rac1 expression declined in the brain.Delayed overexpression of Rac1,using lentivirus encoding Rac1 injected day 1 after ischemic stroke,promoted cognitive(assessed using novel object recognition test)and sensorimotor(assessed using adhesive removal tests)recovery on days 14–28.This was accompanied by the increase of neurite and proliferative endothelial cells in the periinfarct zone assessed by immunostaining.In a reverse approach,pharmacological inhibition of Rac1 by intraperitoneal injection of Rac1 inhibitor NSC23766 for 14 successive days after ischemic stroke worsened the outcome with the reduction of neurite and proliferative endothelial cells.Furthermore,Rac1 inhibition reduced the activation of p21-activated kinase 1,the protein level of brain-derived neurotrophic factor,and increased the protein level of glial fibrillary acidic protein in the ischemic brain on day 28 after stroke.Our work provided insight into the mechanisms behind the diminished plasticity after cerebral ischemia in aged brains and identified Rac1 as a potential therapeutic target for improving functional recovery in the older adults after stroke.

促红细胞生成素对大鼠急性脊髓损伤铜死亡及感觉运动功能的影响

目的探讨促红细胞生成素(EPO)对大鼠急性脊髓损伤(ASCI)铜死亡及感觉运动功能的影响。方法将36只212~236 g雄性SD大鼠按照随机数字表法分为Sham组(行椎板切除)、ASCI组(ASCI建模)和EPO组(行ASCI建模后每日腹腔注射EPO 5000 U/kg,7 d),每组12只。术后进行运动及感觉功能(Reuter)评分、BBB评分及脊髓含水率测量,采用等离子质谱仪检测Cu^(2+)含量,蛋白质印迹技术检测铜死亡蛋白铁氧还原蛋白1(FDX1)及二氢硫辛酰转乙酰基酶(DLAT)的表达水平,比较3组大鼠感觉运动功能、脊髓水肿情况等。结果与Sham组比较,ASCI组和EPO组BBB评分减少(P<0.05),Reuter评分、脊髓含水率、Cu^(2+)含量、FDX1及DLAT表达均增多(P<0.05);与ASCI组比较,EPO组大鼠BBB评分增多(P<0.05),Reuter评分、脊髓含水率、Cu^(2+)含量、FDX1及DLAT表达均减少(P<0.05)。结论EPO可抑制ASCI大鼠铜死亡、减轻脊髓水肿,改善其感觉运动功能。

乳腺癌化疗所致周围神经病变患者运动干预的范围综述

目的对乳腺癌化疗所致周围神经病变运动干预的相关研究进行范围综述,为开展运动干预提供参考。方法基于JBI范围综述框架,系统检索国内外常用数据库,检索时限为建库至2024年3月31日,对检索出的文献进行筛选和信息提取。结果共纳入13篇文献,其中10篇随机对照试验,3篇类实验研究。运动类型包括有氧运动、抗阻运动、感觉运动训练、平衡训练、振动训练、神经舞蹈训练、自行设计的四肢锻炼操等;总干预时长4~12周或化疗时长,运动强度多为轻中度,运动频率多为2~5次/周,30~60 min/次。运动干预评价指标包括安全性、依从性、化疗所致周围神经病变症状及其严重程度、生活质量等。结论运动干预可改善乳腺癌患者化疗所致周围神经病变发生率及严重程度、提高患者生活质量,但运动干预策略和评价标准存在较大差异,有待更多证据以制订最佳运动干预方案。

脑机接口不构成对具身认知的挑战

脑机接口技术通过将主体大脑中的神经信号转化为控制外部设备的指令,从而实现了从思想到行动的直接转化。不少研究者认为,脑机接口表明了认知过程能够以非具身方式实现,因而身体的感知运动过程对于认知来说并非不可或缺。从预测加工的视角看,脑机接口的实现仍然高度依赖主体先验的身体性知识以及“虚拟”的身体行动模式,身体的经验结构对于认知过程具有重要的建构作用。这样的探究不但有助于加深人们对脑机接口的原理、技术实现、应用前景等的认识,而且有助于拓展人们对具身认知相关哲学立场的理解,并在新的视域中重新思考大脑、身体和世界之间的深层次关系。

慢性脑卒中重度偏瘫患者功能恢复的感觉运动皮质重组模式研究

目的:探究慢性脑卒中重度偏瘫患者感觉运动皮质(sensorimotor cortex,SMC)的重组模式及其与上肢运动功能恢复的关系。方法:收集34例慢性脑卒中重度偏瘫患者在4周康复干预前后执行患手被动握拳任务及29例健康人执行单手被动握拳任务的功能磁共振成像数据。比较脑卒中组在康复干预前后SMC的激活差异和偏侧指数(the lateralization index,LI)变化,与上肢运动功能评分(Fugl-Meyer Assessment of Upper Extremity,FMA-UE)进行相关性分析。结果:健康对照组执行单手被动握拳任务时主要表现为对侧脑SMC激活,脑卒中组患手对侧脑SMC的激活变化可分为三种模式:募集、集中和无激活。其中募集模式表现为康复干预后对侧脑SMC激活较干预前增加;集中模式表现为干预后对侧脑SMC激活较干预前减少;无激活模式表现为干预前后对侧脑SMC均无激活。募集组的LI在干预后趋近健康对照组,集中组的LI在干预后偏离并且显著高于健康对照组(P<0.01)。上述三组患者在康复干预后FMA-UE评分均显著增加(P<0.01),而募集组和集中组在康复干预前、后FMA-UE及FMA-UE绝对变化值均不存在显著差异。集中组对侧脑SMC激活的相对变化量与FMA-UE相对变化量显著负相关(r=﹣0.662,P=0.014)。结论:慢性脑卒中重度偏瘫患者在上肢运动功能恢复过程中SMC存在不同重组模式,尤其是SMC募集激活和集中激活的现象,表明慢性脑卒中重度偏瘫患者的运动功能恢复不依赖于单一的皮质功能重组模式。

单侧慢性踝关节不稳对双侧姿势稳定性、本体感觉、足底触觉和肌肉力量的影响

背景:单侧慢性踝关节不稳会对患侧肢体产生不良影响,有线索表明非患侧可能同样受到累及,但目前尚缺乏直接证据。目的:探讨单侧慢性踝关节不稳对于双侧姿势稳定性、本体感觉、足底触觉和肌肉力量的影响。方法:招募122例受试者,其中单侧慢性踝关节不稳者67例,非慢性踝关节不稳者55例。测试了单侧慢性踝关节不稳者双侧以及非慢性踝关节不稳者的姿势稳定性、本体感觉、足底触觉和肌肉力量。使用单因素方差分析或克鲁斯卡尔-沃利斯检验对比组间差异。结果与结论:①相较于非慢性踝关节不稳者,单侧慢性踝关节不稳者双侧前后方向的稳定时间均更长(P=0.001-0.012),患侧内外方向的稳定时间更长(P=0.012-0.025);双侧踝关节跖屈、背伸、内翻和外翻的本体感觉阈值均更高(P=0.000-0.035);双侧足底大脚趾、第1跖骨头、第5跖骨头、外侧足弓、足跟的足底触觉灵敏度均更低(P=0.000-0.008);双侧踝关节内翻和外翻的肌肉力量均更弱(P=0.000-0.019)。②单侧慢性踝关节不稳者存在双侧姿势稳定性、本体感觉、足底触觉和肌肉力量缺陷。因此,在治疗慢性踝关节不稳时应全面考虑双侧肢体的康复需求。

基于家庭赋权的护理干预结合感觉运动训练对脑卒中恢复期患者肢体功能及康复锻炼积极性的影响

目的探讨基于家庭赋权的护理干预结合感觉运动训练对脑卒中恢复期患者肢体功能及康复锻炼积极性的影响。方法选取2020年1月至2022年1月我院收治的88例脑卒中恢复期伴有下肢偏瘫后遗症患者,以随机数字表法将其分为对照组和观察组,各44例。对照组实施常规护理,观察组在对照组基础上实施基于家庭赋权的护理干预结合感觉运动训练。比较两组的干预效果。结果干预后,观察组的Fugl-Meyer评估量表下肢部分(FMA-LE)、Holden步行功能分级量表(FAC)评分高于对照组(P<0.05)。干预后,观察组的股直肌、股二头肌积分肌电值(iEMG)高于对照组(P<0.05)。干预后,观察组的积极举动、康复护理配合度评分高于对照组,放弃举动评分低于对照组(P<0.05)。结论基于家庭赋权的护理干预结合感觉运动训练可促进脑卒中恢复期患者肢体功能恢复,提高康复锻炼积极性,值得推广。

iTBS联合感觉运动整合训练对脑卒中后运动功能障碍患者神经电生理的影响

目的探讨间歇性θ短阵脉冲刺激(iTBS)联合感觉运动整合训练对脑卒中后运动功能障碍患者神经电生理的影响。方法选取2021年3月至2023年8月许昌市立医院收治的脑卒中后运动功能障碍患者96例,根据不同干预方法将患者分为整合训练组(47例)和联合iTBS组(49例)。整合训练组患者采用感觉运动整合训练,联合iTBS组患者采用iTBS联合感觉运动整合训练,两组患者均持续治疗6周。在训练前后,比较两组患者的运动功能量表(FMA)评分、Barthel指数(BI)、美国国立卫生研究院脑卒中量表(NIHSS)评分、神经电生理相关指标[运动诱发电位(MEP)和中枢运动传导时间(CMCT)],比较两组患者并发症发生率,采用t检验或X2检验进行数据对比分析。结果与训练前比较,训练后两组患者上肢运动功能评分和下肢运动功能评分均升高,且训练后联合iTBS组患者上肢运动功能评分(46.97±5.24)分和下肢运动功能评分(21.57±5.22)分均高于整合训练组(41.37±5.16)分、(17.31±5.11)分,差异具有统计学意义(P<0.05)。与训练前比较,训练后两组患者BI评分升高,NIHSS评分降低,训练后联合iTBS组患者BI评分(83.34±5.21)分高于整合训练组(76.37±5.43)分,NIHSS评分(16.05±3.37)分低于整合训练组(20.25±3.51)分,差异具有统计学意义(P<0.05)。训练后两组患者MEP、CMCT均降低,联合iTBS组患者MEP(24.38±3.71)ms、CMCT(10.42±3.15)ms低于整合训练组(26.57±3.22)ms、(13.07±3.06)ms,差异具有统计学意义(P<0.05)。训练后,联合iTBS组(6.12%)和整合训练组(8.51%)患者并发症发生率比较差异无统计学意义(P>0.05)。结论iTBS联合感觉运动整合训练能够促进脑卒中后运动功能障碍患者运动功能、日常生活能力和神经功能恢复。

Reduction of Interhemispheric Functional Connectivity in Sensorimotor and Visual Information Processing Pathways in Schizophrenia

Background： Previous studies have demonstrated interhemispheric functional connectivity alterations in schizophrenia. However, the relationship between these alterations and the disease state of schizophrenia is largely unknown. Therefore, we aimed to investigate this relationship using voxel-mirrored homotopic connectivity （VMHC） method. Methods： This study enrolled 36 schizophrenia patients with complete remission, 58 schizophrenia patients with incomplete remission and 55 healthy controls. The VMHC was calculated based on resting-state functional magnetic resonance imaging data. Differences in VMHC among three groups were compared using one-way analysis of variance. A brain region with a significant difference in VMHC was defined as a region of interest （ROI）, and the mean VMHC value in the ROI was extracted for the post hoc analysis, i.e., pair-wise comparisons across the three groups. Results： VMHC in the visual region （inferior occipital and fusiform gyri） and the sensorimotor region （paracentral lobule） showed significant differences among the three groups （P 〈 0.05, a false discovery rate method corrected）. Pair-wise comparisons in the post hoc analysis showed that VMHC of the visual and sensorimotor regions in schizophrenia patients with complete remission and incomplete remission was lower than that in healthy controls （P 〈 0.05, Bonferroni corrected）; however, there was no significant difference between the two patient subgroups. Conclusions： Interhemispheric functional connectivity in the sensorimotor and visual processing pathways was reduced in patients with schizophrenia, but this reduction was unrelated to the disease state; thus, this reduction may serve as a trait marker of schizophrenia.

Ventromedial Thalamus-Projecting DCN Neurons Modulate Associative Sensorimotor Responses in Mice

The deep cerebellar nuclei(DCN)integrate various inputs to the cerebellum and form the final cerebellar outputs critical for associative sensorimotor learning.However,the functional relevance of distinct neuronal subpopulations within the DCN remains poorly understood.Here,we examined a subpopulation of mouse DCN neurons whose axons specifically project to the ventromedial(Vm)thalamus(DCNVm neurons),and found that these neurons represent a specific subset of DCN units whose activity varies with trace eyeblink conditioning(tEBC),a classical associative sensorimotor learning task.Upon conditioning,the activity of DCNVm neurons signaled the performance of conditioned eyeblink responses(CRs).Optogenetic activation and inhibition of the DCNVm neurons in well-trained mice amplified and diminished the CRs,respectively.Chemogenetic manipulation of the DCNVm neurons had no effects on non-associative motor coordination.Furthermore,optogenetic activation of the DCNVm neurons caused rapid elevated firing activity in the cingulate cortex,a brain area critical for bridging the time gap between sensory stimuli and motor execution during tEBC.Together,our data highlights DCNVm neurons’function and delineates their kinematic parameters that modulate the strength of associative sensorimotor responses.

Sensorimotor Self-Learning Model Based on Operant Conditioning for Two-Wheeled Robot

Traditional control methods of two-wheeled robot are usually model-based and require the robot’s precise mathematic model which is hard to get. A sensorimotor self-learning model named SMM TWR is presented in this paper to handle these problems. The model consists of seven elements: the discrete learning time set, the sensory state set, the motion set, the sensorimotor mapping, the state orientation unit, the learning mechanism and the model’s entropy. The learning mechanism for SMM TWR is designed based on the theory of operant conditioning (OC), and it adjusts the sensorimotor mapping at every learning step. This helps the robot to choose motions. The leaning direction of the mechanism is decided by the state orientation unit. Simulation results show that with the sensorimotor model designed, the robot is endowed the abilities of self-learning and self-organizing, and it can learn the skills to keep itself balance through interacting with the environment. © 2017, Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.

Anovel multi-dimensional features fusion algorithm for the EEG signal recognition of brain’s sensorimotor region activated tasks

Purpose-Aiming at the shortcomings of EEG signals generated by brain’s sensorimotor region activated tasks,such as poor performance,low efficiency and weak robustness,this paper proposes an EEG signals classification method based on multi-dimensional fusion features.Design/methodology/approach-First,the improved Morlet wavelet is used to extract the spectrum feature maps from EEG signals.Then,the spatial-frequency features are extracted from the PSD maps by using the three-dimensional convolutional neural networks(3DCNNs)model.Finally,the spatial-frequency features are incorporated to the bidirectional gated recurrent units(Bi-GRUs)models to extract the spatial-frequencysequential multi-dimensional fusion features for recognition of brain’s sensorimotor region activated task.Findings-In the comparative experiments,the data sets of motor imagery(MI)/action observation(AO)/action execution(AE)tasks are selected to test the classification performance and robustness of the proposed algorithm.In addition,the impact of extracted features on the sensorimotor region and the impact on the classification processing are also analyzed by visualization during experiments.Originality/value-The experimental results show that the proposed algorithm extracts the corresponding brain activation features for different action related tasks,so as to achieve more stable classification performance in dealing with AO/MI/AE tasks,and has the best robustness on EEGsignals of different subjects.

加工深度对动词感知运动模拟的影响

目的:探究动词理解的加工深度对动词感知运动模拟过程的影响及其自动化特性。方法:研究招募36名普通大学生,依次完成实验1和实验2,分别要求被试完成动词语义判断任务及非语义判断任务,并观察对应手、脚动作输出的行为表现变化。结果:实验1中,在语义判断任务条件下,腿部动词腿部执行的反应时显著快于手部动词腿部执行的反应时(P=0.001);真假词判断任务条件下,不存在显著差异。实验2中,未发现动词类型与动作执行的显著交互作用(P=0.199)。结论:动词理解引发感知运动模拟的现象受到了不同加工深度的调节,在高加工深度下,个体更倾向于利用感知运动模拟来理解动词,且该过程是非自动化的。

Impaired auditory sensorimotor gating: An animal model of schizophrenia

Establishment of animal models of schizophrenia is critical for both understanding the mechanisms underlying this severe mental disease and developing new antipsychotics. This paper starts from the theoretical root of sensory gating, the 損rotection-of-processing?theory, then thoroughly describes the representative studies over the past decade on the mechanism underlying prepulse inhibition and on those underlying modulation of prepulse inhibition, which is the normal startle suppression caused by the weak stimulus preceding the intense startling stimulus. The main methods for inducing prepulse inhibition deficits in experimental animals include: ⅰ) modulations of neuro- transmission that are closely associated with schizophrenia; ⅱ) focal lesions or pharmacological manipulations of brain structures in the cortico-striato-pallido-pontine circuit; and ⅲ) maternal deprivation or social isolation. Six essential topics for studies in modeling schizophrenia are suggested at the last part of this review.

感觉运动训练在老年精神分裂症病人护理中的应用

目的:探讨感觉运动训练在老年精神分裂症病人护理中的应用效果。方法:选取2020年1月—8月我院精神科收治的老年精神分裂症病人60例作为研究对象,采用信封法将病人分为对照组(30例)和观察组(30例)。对照组采取常规的康复护理,观察组在常规康复护理基础上开展感觉运动训练。采用蒙特利尔认知量表(MoCA)、功能独立性评定量表(FIM)、世界卫生组织生存质量测定量表简表(WHOQOL-BREF)分别评价病人的认知功能、独立生活能力、生存质量。结果:干预后10周,观察组MoCA总分及各维度得分高于干预前及同期对照组(P<0.05);观察组FIM总分及进食、梳洗修饰、洗澡、穿裤子、穿上衣、上厕所、膀胱管理、床或椅或轮椅间转移、入厕、盆浴或淋浴、步行/轮椅、上下楼梯、理解、表达、社会交往、解决问题、记忆维度得分高于干预前及同期对照组(P<0.05);观察组WHOQOL-BREF中的生理领域、心理领域、社会关系领域维度得分高于干预前及同期对照组(P<0.05)。结论:对老年精神分裂症病人实施感觉运动训练,能够提升病人认知功能,提高病人独立生活能力和生存质量。

Alpha2-adrenergic receptor activation reinstates motor deficits in rats recovering from cortical injury

Norepinephrine plays an important role in motor functional recovery after a brain injury caused by ferrous chloride.Inhibition of norepinephrine release by clonidine is correlated with motor deficits after motor cortex injury.The aim of this study was to analyze the role ofα-adrenergic receptors in the restoration of motor deficits in recovering rats after brain damage.The rats were randomly assigned to the sham and injury groups and then treated with the following pharmacological agents at 3 hours before and 8 hours,3 days,and 20 days after ferrous chloride-induced cortical injury:saline,clonidine,efaroxan(a selective antagonist ofα-adrenergic receptors)and clonidine+efaroxan.The sensorimotor score,the immunohistochemical staining forα-adrenergic receptors,and norepinephrine levels were evaluated.Eight hours post-injury,the sensorimotor score and norepinephrine levels in the locus coeruleus of the injured rats decreased,and these effects were maintained 3 days post-injury.However,20 days later,clonidine administration diminished norepinephrine levels in the pons compared with the sham group.This effect was accompanied by sensorimotor deficits.These effects were blocked by efaroxan.In conclusion,an increase inα-adrenergic receptor levels was observed after injury.Clonidine restores motor deficits in rats recovering from cortical injury,an effect that was prevented by efaroxan.The underlying mechanisms involve the stimulation of hypersensitiveα-adrenergic receptors and inhibition of norepinephrine activity in the locus coeruleus.The results of this study suggest thatαreceptor agonists might restore deficits or impede rehabilitation in patients with brain injury,and therefore pharmacological therapies need to be prescribed cautiously to these patients.