- 作者列表："Wang Z","Wang SN","Xu TY","Hong C","Cheng MH","Zhu PX","Lin JS","Su DF","Miao CY
BACKGROUND AND PURPOSE:Cerebral organoids (COs) have been used for studying brain development, neural disorders, and species-specific drug pharmacology and toxicology, but the potential of COs transplantation therapy for brain injury remains to be answered. METHODS:With preparation of traumatic brain injury (TBI) model of motor dysfunction, COs at 55 and 85 days (55 and 85 d-CO) were transplanted into damaged motor cortex separately to identify better transplantation donor for brain injury. Further, the feasibility, effectiveness, and underlying mechanism of COs transplantation therapy for brain injury were explored. RESULTS:55 d-CO was demonstrated as better transplantation donor than 85 d-CO, evidenced by more neurogenesis and higher cell survival rate without aggravating apoptosis and inflammation after transplantation into damaged motor cortex. Cells from transplanted COs had the potential of multilinage differentiation to mimic in-vivo brain cortical development, support region-specific reconstruction of damaged motor cortex, form neurotransmitter-related neurons, and migrate into different brain regions along corpus callosum. Moreover, COs transplantation upregulated hippocampal neural connection proteins and neurotrophic factors. Notably, COs transplantation improved neurological motor function and reduced brain damage. CONCLUSIONS:This study revealed 55 d-CO as better transplantation donor and demonstrated the feasibility and efficacy of COs transplantation in TBI, hoping to provide first-hand preclinical evidence of COs transplantation for brain injury.
背景与目的: 脑类器官 (COs) 已被用于研究脑发育、神经疾病和种属特异性药物药理学和毒理学, 但 COs 移植治疗脑损伤的潜力仍有待回答。 方法: 制备创伤性脑损伤 (TBI) 运动功能障碍模型，在 55 天和 85 天 (55 和 85 d-CO) 分别移植到受损的运动皮层，以确定更好的脑损伤移植供体。进一步探讨 COs 移植治疗脑损伤的可行性、有效性和潜在机制。 结果: 55 d-CO 比 85 d-CO 具有更好的移植供体，移植到受损运动皮层后，神经发生更多，细胞存活率更高，且不加重细胞凋亡和炎症。移植 COs 的细胞具有多线分化的潜力，模拟体内大脑皮层发育，支持受损运动皮层的区域特异性重建，形成神经递质相关神经元, 并沿胼胝体迁移到不同的脑区。此外，COs 移植上调海马神经连接蛋白和神经营养因子。值得注意的是，COs 移植改善了神经运动功能，减少了脑损伤。 结论: 本研究揭示了 55 d-CO 是更好的移植供体，并证明了 COs 移植在 TBI 中的可行性和疗效，希望为 COs 移植治疗脑损伤提供第一手临床前证据。
METHODS::In recent years, transcranial electrical stimulation (tES) has been used to improve cognitive and perceptual abilities and to boost learning. In the visual domain, transcranial random noise stimulation (tRNS), a type of tES in which electric current is randomly alternating in between two electrodes at high frequency, has shown potential in inducing long lasting perceptual improvements when coupled with tasks such as contrast detection. However, its cortical mechanisms and online effects have not been fully understood yet, and it is still unclear whether these long-term improvements are due to early-stage perceptual enhancements of contrast sensitivity or later stage mechanisms such as learning consolidation. Here we tested tRNS effects on multiple spatial frequencies and orientation, showing that tRNS enhances detection of a low contrast Gabor, but only for oblique orientation and high spatial frequency (12 cycles per degree of visual angle). No improvement was observed for low contrast and vertical stimuli. These results indicate that tRNS can enhance contrast sensitivity already after one training session, however this early onset is dependent on characteristics of the stimulus such as spatial frequency and orientation. In particular, the shallow depth of tRNS is likely to affect superficial layers of the visual cortex where neurons have higher preferred spatial frequencies than cells in further layers, while the lack of effect on vertical stimuli might reflect the optimization of the visual system to see cardinally oriented low contrast stimuli, leaving little room for short-term improvement. Taken together, these results suggest that online tRNS effects on visual perception are the result of a complex interaction between stimulus intensity and cortical anatomy, consistent with previous literature on brain stimulation.
METHODS:OBJECTIVE:There is growing interest in treating diseases by electrical stimulation and block of peripheral autonomic nerves, but a paucity of studies on excitation and block of small diameter autonomic axons. We conducted in vivo quantification of the strength-duration properties, activity-dependent slowing (ADS), and responses to kilohertz frequency (KHF) signals for the rat vagus nerve (VN). APPROACH:We conducted acute in vivo experiments in urethane-anesthetised rats. We placed two cuff electrodes on the left cervical VN and one cuff electrode on the anterior subdiaphragmatic VN. The rostral cervical cuff was used to deliver pulses to quantify recruitment and ADS. The caudal cervical cuff was used to deliver KHF signals. The subdiaphragmatic cuff was used to record compound action potentials (CAPs). MAIN RESULTS:We quantified the input-output recruitment and strength-duration curves. Fits to the data using standard strength-duration equations were qualitatively similar, but the resulting chronaxie and rheobase estimates varied substantially. We measured larger thresholds for the slowest fibres (0.5 to 1 m/s), especially at shorter pulse widths. Using a novel cross-correlation CAP-based analysis, we measured ADS of ~2.3% after 3 min of 2 Hz stimulation, which is comparable to ADS reported for sympathetic efferents in somatic nerves, but much smaller than ADS in cutaneous nociceptors. We found greater ADS with higher stimulation frequency and non-monotonic changes in CV in select cases. We found monotonically increasing block thresholds across frequencies from 10 to 80 kHz for both fast and slow fibres. Further, following 25 s of KHF signal, neural conduction could require tens of seconds to recover. SIGNIFICANCE:The quantification of mammalian autonomic nerve responses to conventional and KHF signals provides essential information for development of peripheral nerve stimulation therapies and for understanding their mechanisms of action.
METHODS:BACKGROUND:Early accounts of forced thought were reported at the onset of a focal seizure, and characterized as vague, repetitive, and involuntary intellectual auras distinct from perceptual or psychic hallucinations or illusions. Here, we examine the neural underpinnings involved in conceptual thought by presenting a series of 3 patients with epilepsy reporting intrusive thoughts during electrical stimulation of the left lateral prefrontal cortex (PFC) during invasive surgical evaluation. We illustrate the widespread networks involved through two independent brain imaging modalities: resting state functional magnetic resonance imaging (fMRI) (rs-fMRI) and task-based meta-analytic connectivity modeling (MACM). METHODS:We report the clinical and stimulation characteristics of three patients with left hemispheric language dominance who demonstrate forced thought with functional mapping. To examine the brain networks underlying this phenomenon, we used the regions of interest (ROI) centered at the active electrode pairs. We modeled functional networks using two approaches: (1) rs-fMRI functional connectivity analysis, representing 81 healthy controls and (2) meta-analytic connectivity modeling (MACM), representing 8260 healthy subjects. We also determined the overlapping regions between these three subjects' rs-fMRI and MACM networks through a conjunction analysis. RESULTS:We identified that left PFC was associated with a large-scale functional network including frontal, temporal, and parietal regions, a network that has been associated with multiple cognitive functions including semantics, speech, attention, working memory, and explicit memory. CONCLUSIONS:We illustrate the neural networks involved in conceptual thought through a unique patient population and argue that PFC supports this function through activation of a widespread network.