Pub Date : 2024-11-05DOI: 10.1016/j.expneurol.2024.115044
Xudong Hu , Lixia Liu , Xin Da , Sihui Zhu , Jiawei Wang , Menglei Shan , Yinuo Liu , Ziqing He , Guanghong Xu
Aims
Postoperative delirium (POD) is a common complication of anesthesia and surgery, with a higher incidence in elderly patients. Disruption of the blood-brain barrier (BBB) is considered one of the key mechanisms underlying POD. Therefore, the present study aimed to investigate the effects of different BBB permeability alteration pathways on POD in mice of various ages.
Methods
C57BL/6 J mice aged 4 and 16 months underwent exploratory laparotomy under sevoflurane anesthesia. Behavioral tests were conducted 24 h prior to surgery, as well as 6, 9, and 24 h postoperatively. Frontal cortex tissue was collected to detect the levels of BBB-related proteins and mRNA.
Results
At 6 and 9 h after anesthesia/surgery, 4-month-old mice showed poorer performance on behavioral tests than their untreated counterparts. However, 16-month-old mice exhibited worse behavioral test results at 6, 9, and 24 h after surgery. Anesthesia/surgery 6 h postoperatively increased the expression of vesicle-associated proteins, and BBB leakage in 4-month-old mice. In 16-month-old mice, anesthesia/surgery altered the expression of tight junction proteins, vesicle-associated proteins, and BBB leakage at 6 and 24 h postoperatively.
Conclusion
Overall, our results suggest that anesthesia/surgery leads to age-dependent cognitive decline, and is associated with differences in the BBB injury pathways among mice of different ages. The transcellular pathway (transcytosis), compared to the paracellular pathway (tight junction), is more vulnerable to damage following anesthesia/surgery. This study provides new evidence for the improvement of POD through protection of the BBB.
{"title":"Anesthesia/surgery leads to blood-brain barrier disruption via the transcellular and paracellular pathways, and postoperative delirium-like behavior: A comparative study in mice of different ages","authors":"Xudong Hu , Lixia Liu , Xin Da , Sihui Zhu , Jiawei Wang , Menglei Shan , Yinuo Liu , Ziqing He , Guanghong Xu","doi":"10.1016/j.expneurol.2024.115044","DOIUrl":"10.1016/j.expneurol.2024.115044","url":null,"abstract":"<div><h3>Aims</h3><div>Postoperative delirium (POD) is a common complication of anesthesia and surgery, with a higher incidence in elderly patients. Disruption of the blood-brain barrier (BBB) is considered one of the key mechanisms underlying POD. Therefore, the present study aimed to investigate the effects of different BBB permeability alteration pathways on POD in mice of various ages.</div></div><div><h3>Methods</h3><div>C57BL/6 J mice aged 4 and 16 months underwent exploratory laparotomy under sevoflurane anesthesia. Behavioral tests were conducted 24 h prior to surgery, as well as 6, 9, and 24 h postoperatively. Frontal cortex tissue was collected to detect the levels of BBB-related proteins and mRNA.</div></div><div><h3>Results</h3><div>At 6 and 9 h after anesthesia/surgery, 4-month-old mice showed poorer performance on behavioral tests than their untreated counterparts. However, 16-month-old mice exhibited worse behavioral test results at 6, 9, and 24 h after surgery. Anesthesia/surgery 6 h postoperatively increased the expression of vesicle-associated proteins, and BBB leakage in 4-month-old mice. In 16-month-old mice, anesthesia/surgery altered the expression of tight junction proteins, vesicle-associated proteins, and BBB leakage at 6 and 24 h postoperatively.</div></div><div><h3>Conclusion</h3><div>Overall, our results suggest that anesthesia/surgery leads to age-dependent cognitive decline, and is associated with differences in the BBB injury pathways among mice of different ages. The transcellular pathway (transcytosis), compared to the paracellular pathway (tight junction), is more vulnerable to damage following anesthesia/surgery. This study provides new evidence for the improvement of POD through protection of the BBB.</div></div>","PeriodicalId":12246,"journal":{"name":"Experimental Neurology","volume":"383 ","pages":"Article 115044"},"PeriodicalIF":4.6,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142589652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.expneurol.2024.115047
Kaitlyn Hair, María Arroyo Araujo, Sofija Vojvodic, Maria Economou, Charis Wong, Francesca Tinsdeall, Sean Smith, Torsten Rackoll, Emily S Sena, Sarah K McCann
Making progress in neuroscience research involves learning from existing data. In this perspective piece, we explore the potential of a data-driven evidence ecosystem to connect all primary data streams, and synthesis efforts to inform evidence-based research and translational success from bench to bedside. To enable this transformation, we set out how we can produce evidence designed with evidence curation in mind. All data should be findable, understandable, and easily synthesisable, using a combination of human and machine effort. This will require shifts in research culture and tailored infrastructure to support rapid dissemination, data sharing, and transparency. We also discuss improvements in the way we can synthesise evidence to better inform primary research, including the potential of emerging technologies, big-data approaches, and breaking down research silos. Through a case study in stroke research, one of the most well-established areas for synthesis efforts, we demonstrate the progress in implementing elements of this ecosystem, with an emphasis on the need for coordinated efforts between laboratory researchers and synthesists.
{"title":"Connecting the dots in neuroscience research: The future of evidence synthesis.","authors":"Kaitlyn Hair, María Arroyo Araujo, Sofija Vojvodic, Maria Economou, Charis Wong, Francesca Tinsdeall, Sean Smith, Torsten Rackoll, Emily S Sena, Sarah K McCann","doi":"10.1016/j.expneurol.2024.115047","DOIUrl":"https://doi.org/10.1016/j.expneurol.2024.115047","url":null,"abstract":"<p><p>Making progress in neuroscience research involves learning from existing data. In this perspective piece, we explore the potential of a data-driven evidence ecosystem to connect all primary data streams, and synthesis efforts to inform evidence-based research and translational success from bench to bedside. To enable this transformation, we set out how we can produce evidence designed with evidence curation in mind. All data should be findable, understandable, and easily synthesisable, using a combination of human and machine effort. This will require shifts in research culture and tailored infrastructure to support rapid dissemination, data sharing, and transparency. We also discuss improvements in the way we can synthesise evidence to better inform primary research, including the potential of emerging technologies, big-data approaches, and breaking down research silos. Through a case study in stroke research, one of the most well-established areas for synthesis efforts, we demonstrate the progress in implementing elements of this ecosystem, with an emphasis on the need for coordinated efforts between laboratory researchers and synthesists.</p>","PeriodicalId":12246,"journal":{"name":"Experimental Neurology","volume":" ","pages":"115047"},"PeriodicalIF":4.6,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142603652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.expneurol.2024.115042
Ricardo Schmidt , Björn Welzel , Annika Merten , Hannah Naundorf , Wolfgang Löscher
Birth asphyxia (BA) and subsequent hypoxic-ischemic encephalopathy (HIE) is one of the most serious birth complications affecting full-term infants and can result in severe disabilities including mental retardation, cerebral palsy, and epilepsy. Animal models of BA and HIE are important to characterize the functional and behavioral correlates of injury, explore cellular and molecular mechanisms, and assess the potential of novel therapeutic strategies. Here we used a non-invasive, physiologically validated rat model of BA and acute neonatal seizures that mimics many features of BA and HIE in human infants to study (i) the temporal development of epilepsy with spontaneous recurrent seizures (SRS) in the weeks and months after the initial brain injury, (ii) alterations in seizure threshold and hippocampal EEG that may precede the onset of SRS, and (iii) the effect of prophylactic treatment with midazolam. For this purpose, a total of 89 rat pups underwent asphyxia or sham asphyxia at postnatal day 11 and were examined over 8–10.5 months. In vehicle-treated animals, the incidence of electroclinical SRS progressively increased from 0 % at 2.5 months to 50 % at 6.5 months, 75 % at 8.5 months, and > 80 % at 10.5 months after asphyxia. Unexpectedly, post-asphyxial rats did not differ from sham-exposed rats in seizure threshold or interictal epileptiform discharges in the EEG. Treatment with midazolam (1 mg/kg i.p.) after asphyxia, which suppressed acute symptomatic neonatal seizures in about 60 % of the rat pups, significantly reduced the incidence of SRS regardless of its effect on neonatal seizures. This antiepileptogenic effect of midazolam adds to the recently reported prophylactic effects of this drug on BA-induced neuroinflammation, brain damage, behavioral alterations, and cognitive impairment in the rat asphyxia model of HIE.
出生窒息(BA)和随后的缺氧缺血性脑病(HIE)是影响足月婴儿的最严重出生并发症之一,可导致严重残疾,包括智力低下、脑瘫和癫痫。BA 和 HIE 的动物模型对于描述损伤的功能和行为相关性、探索细胞和分子机制以及评估新型治疗策略的潜力非常重要。在这里,我们使用了一种非侵入性、生理验证的大鼠 BA 和新生儿急性癫痫发作模型,该模型模拟了人类婴儿 BA 和 HIE 的许多特征,以研究:(i) 初始脑损伤后数周和数月内癫痫与自发性复发性癫痫发作(SRS)的时间发展;(ii) SRS 开始前癫痫发作阈值和海马脑电图的改变;(iii) 咪达唑仑预防性治疗的效果。为此,共对89只幼鼠在出生后第11天进行了窒息或假窒息,并在8-10.5个月内进行了检查。在接受过药物治疗的动物中,电临床 SRS 的发生率从窒息后 2.5 个月时的 0% 逐步上升到 6.5 个月时的 50%、8.5 个月时的 75%,以及 10.5 个月时的 80%。意想不到的是,窒息后的大鼠与假暴露的大鼠在癫痫发作阈值或脑电图中发作间期癫痫样放电方面没有区别。窒息后使用咪达唑仑(1 毫克/千克,静脉注射)治疗可抑制约 60% 的幼鼠的新生儿急性症状性癫痫发作,无论其对新生儿癫痫发作的影响如何,都能显著降低 SRS 的发生率。除了咪达唑仑的这种抗致痫作用外,最近还报道了这种药物对BA诱导的神经炎症、脑损伤、行为改变和HIE窒息模型大鼠认知障碍的预防作用。
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Pub Date : 2024-11-03DOI: 10.1016/j.expneurol.2024.115040
Marcello Serra , Gaia Faustini , Viviana Brembati , Maria Antonietta Casu , Marina Pizzi , Micaela Morelli , Annalisa Pinna , Arianna Bellucci
Parkinson's disease (PD) is characterized by the loss of nigrostriatal dopaminergic neurons and the presence of Lewy bodies (LB), intraneuronal inclusions mainly composed of α-synuclein (α-Syn) fibrils. Compelling evidence supports that, in PD brains, synapses are the sites where neurodegeneration initiates several years before the manifestation of motor symptoms. Furthermore, the amount of α-Syn deposited at synaptic terminals is several orders greater than that constituting LB. This hints that pathological synaptic α-Syn aggregates may be the main trigger for the retrograde synapse-to-cell body degeneration pattern characterizing early prodromal phases of PD. Identifying reliable biomarkers of synaptopathy is therefore crucial for early diagnosis. Here, we studied the alterations of key dopaminergic and non-dopaminergic striatal synaptic markers during the initial phases of axonal and cell body degeneration in mice subjected to 3 or 10 administrations of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine + probenecid (MPTPp), a model for early prodromal PD. We found that MPTPp administration resulted in progressive deposition of α-Syn, advancing from synaptic terminals to axons and dopaminergic neuron cell bodies. This was accompanied by marked co-accumulation of Synapsin III (Syn III), a synaptic protein previously identified as a component of α-Syn fibrils in post-mortem PD brains and as a main stabilizer of α-Syn aggregates, as well as very early and severe reduction of vesicular monoamine transporter 2 (VMAT2), dopamine transporter (DAT) and tyrosine hydroxylase (TH) immunoreactivity in nigrostriatal neurons. Results also showed that striatal α-Syn accumulation and VMAT2 decrease, unlike other markers, did not recover following washout from 10 MPTPp administrations, supporting that these changes were precocious and severe. Finally, we found that early changes in striatal α-Syn, Syn III, VMAT2 and DAT observed following 3 MPTPp administrations, correlated with nigrostriatal neuron loss after 10 MPTPp administrations. These findings indicate that α-Syn/Syn III co-deposition characterizes very early stages of striatal dopaminergic dysfunction in the MPTPp model and highlight that VMAT2 and Syn III could be two reliable molecular imaging biomarkers to predict dopamine neuron denervation and estimate α-Syn-related synaptopathy in prodromal and early symptomatic phases of PD.
帕金森病(PD)的特征是黑质多巴胺能神经元的丧失和路易体(LB)的存在,路易体是一种主要由α-突触核蛋白(α-Syn)纤维组成的内含物。有令人信服的证据表明,在帕金森病患者的大脑中,突触是神经变性的起始部位,比运动症状出现早数年。此外,沉积在突触末端的α-Syn的数量比构成LB的α-Syn多几个数量级。这表明,病理突触α-Syn聚集可能是导致逆行性突触-细胞体变性模式的主要诱因,而这种模式正是帕金森病早期前驱阶段的特征。因此,确定突触病的可靠生物标志物对于早期诊断至关重要。在这里,我们研究了小鼠在轴突和细胞体变性的初期阶段多巴胺能和非多巴胺能纹状体突触关键标记物的变化,这些标记物是在给小鼠注射3次或10次1-甲基-4-苯基-1,2,3,6-四氢吡啶+丙磺舒(MPTPp)后出现的。我们发现,服用 MPTPp 会导致 α-Syn 逐渐沉积,并从突触末端向轴突和多巴胺能神经元细胞体推进。与此同时,黑质神经元中的囊泡单胺转运体 2(VMAT2)、多巴胺转运体(DAT)和酪氨酸羟化酶(TH)的免疫活性也在极早期出现严重下降。结果还显示,与其他标记物不同,纹状体α-Syn的积累和VMAT2的减少在10次MPTPp给药冲洗后并没有恢复,这证明这些变化是早熟和严重的。最后,我们发现在注射 3 次 MPTPp 后观察到的纹状体 α-Syn、Syn III、VMAT2 和 DAT 的早期变化与注射 10 次 MPTPp 后黑质神经元的缺失相关。这些研究结果表明,在 MPTPp 模型中,α-Syn/Syn III 协同沉积是纹状体多巴胺能功能障碍的早期阶段的特征,并强调 VMAT2 和 Syn III 可作为两种可靠的分子成像生物标记物,用于预测多巴胺神经元去神经化,并估计与α-Syn 相关的突触病变在帕金森病前驱期和早期症状期的情况。
{"title":"Early α-synuclein/synapsin III co-accumulation, nigrostriatal dopaminergic synaptopathy and denervation in the MPTPp mouse model of Parkinson's Disease","authors":"Marcello Serra , Gaia Faustini , Viviana Brembati , Maria Antonietta Casu , Marina Pizzi , Micaela Morelli , Annalisa Pinna , Arianna Bellucci","doi":"10.1016/j.expneurol.2024.115040","DOIUrl":"10.1016/j.expneurol.2024.115040","url":null,"abstract":"<div><div>Parkinson's disease (PD) is characterized by the loss of nigrostriatal dopaminergic neurons and the presence of Lewy bodies (LB), intraneuronal inclusions mainly composed of α-synuclein (α-Syn) fibrils. Compelling evidence supports that, in PD brains, synapses are the sites where neurodegeneration initiates several years before the manifestation of motor symptoms. Furthermore, the amount of α-Syn deposited at synaptic terminals is several orders greater than that constituting LB. This hints that pathological synaptic α-Syn aggregates may be the main trigger for the retrograde synapse-to-cell body degeneration pattern characterizing early prodromal phases of PD. Identifying reliable biomarkers of synaptopathy is therefore crucial for early diagnosis. Here, we studied the alterations of key dopaminergic and non-dopaminergic striatal synaptic markers during the initial phases of axonal and cell body degeneration in mice subjected to 3 or 10 administrations of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine + probenecid (MPTPp), a model for early prodromal PD. We found that MPTPp administration resulted in progressive deposition of α-Syn, advancing from synaptic terminals to axons and dopaminergic neuron cell bodies. This was accompanied by marked co-accumulation of Synapsin III (Syn III), a synaptic protein previously identified as a component of α-Syn fibrils in post-mortem PD brains and as a main stabilizer of α-Syn aggregates, as well as very early and severe reduction of vesicular monoamine transporter 2 (VMAT2), dopamine transporter (DAT) and tyrosine hydroxylase (TH) immunoreactivity in nigrostriatal neurons. Results also showed that striatal α-Syn accumulation and VMAT2 decrease, unlike other markers, did not recover following washout from 10 MPTPp administrations, supporting that these changes were precocious and severe. Finally, we found that early changes in striatal α-Syn, Syn III, VMAT2 and DAT observed following 3 MPTPp administrations, correlated with nigrostriatal neuron loss after 10 MPTPp administrations. These findings indicate that α-Syn/Syn III co-deposition characterizes very early stages of striatal dopaminergic dysfunction in the MPTPp model and highlight that VMAT2 and Syn III could be two reliable molecular imaging biomarkers to predict dopamine neuron denervation and estimate α-Syn-related synaptopathy in prodromal and early symptomatic phases of PD.</div></div>","PeriodicalId":12246,"journal":{"name":"Experimental Neurology","volume":"383 ","pages":"Article 115040"},"PeriodicalIF":4.6,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142581877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/j.expneurol.2024.115041
Yingfeng Wan , Qing Xie , Ya Hua, Guohua Xi, Richard F. Keep, Aditya Pandey
Background
Intracerebral hemorrhage (ICH) often impacts patient white matter. However, preclinically, the effects of ICH are mostly studied in rodents with sparse white matter. This study used a lobar porcine ICH model to examine differences in the effects of ICH on white and gray matter as well as the role of the iron chelator deferoxamine (DFX), on attenuation of such injury.
Methods
This two-part study was performed in piglets. Firstly, piglets had a needle (Sham) or 2.5 ml blood injection (ICH) and were euthanized at day 3. Secondly, animals were treated with vehicle or DFX after ICH and were euthanized at day 3. White and gray matter edema, the number of oligodendrocytes (mature and immature) and neurons, and the number of Perls' (iron), ferritin and heme oxygenase (HO)-1 positive cells were examined.
Results
At day 3, ICH induced greater edema formation in white than gray matter. This marked white matter edema was associated with a loss of mature, but not immature, oligodendrocytes. ICH also induced neuronal death in gray matter. There were also marked increases in Perls', ferritin and HO-1 positive cells after ICH in both white and gray matter, but significantly more in the former. DFX attenuated ICH-induced brain edema in white but not gray matter and this was associated with increased survival of mature oligodendrocytes. DFX also increased survival of neurons in the gray matter and it reduced the number of Perls', ferritin and HO-1 positive cells in both tissue types.
Conclusions
While there were commonalities in perihematomal changes between white and gray matter after ICH, there was greater edema in white matter which may be linked to the susceptibility of mature oligodendrocytes to ICH injury. Similarly, while DFX reduced perihematomal iron overload in both white and gray matter, it only significantly reduced edema in white matter where it increased the number of mature oligodendrocytes.
背景:脑出血(ICH)通常会影响患者的白质。然而,临床前大多是在白质稀少的啮齿类动物中研究 ICH 的影响。本研究使用猪叶 ICH 模型来研究 ICH 对白质和灰质影响的差异,以及铁螯合剂去铁胺(DFX)对减轻这种损伤的作用:这项研究以仔猪为对象,由两部分组成。首先,对仔猪进行针刺(Sham)或 2.5 毫升血液注射(ICH),并在第 3 天实施安乐死。其次,动物在 ICH 后接受药物或 DFX 治疗,并在第 3 天安乐死。对白质和灰质水肿、少突胶质细胞(成熟和未成熟)和神经元的数量、Perls'(铁)、铁蛋白和血红素加氧酶(HO)-1阳性细胞的数量进行了检测:结果:在第 3 天,ICH 引起的白质水肿大于灰质水肿。这种明显的白质水肿与成熟少突胶质细胞(而非未成熟少突胶质细胞)的丧失有关。ICH 还诱导灰质中神经元的死亡。ICH 后,白质和灰质中的 Perls'、铁蛋白和 HO-1 阳性细胞也明显增加,但前者明显增加更多。DFX 可减轻 ICH 引起的白质脑水肿,但不能减轻灰质脑水肿,这与成熟少突胶质细胞存活率增加有关。DFX还提高了灰质中神经元的存活率,并减少了两种组织类型中Perls'、铁蛋白和HO-1阳性细胞的数量:结论:虽然 ICH 后白质和灰质的血肿周围变化有共同之处,但白质的水肿更严重,这可能与成熟的少突胶质细胞易受 ICH 损伤有关。同样,虽然 DFX 能减轻白质和灰质血肿周围的铁超载,但它只能显著减轻白质的水肿,因为它能增加成熟少突胶质细胞的数量。
{"title":"Comparing white and gray matter responses to lobar intracerebral hemorrhage in piglets and the effects of deferoxamine","authors":"Yingfeng Wan , Qing Xie , Ya Hua, Guohua Xi, Richard F. Keep, Aditya Pandey","doi":"10.1016/j.expneurol.2024.115041","DOIUrl":"10.1016/j.expneurol.2024.115041","url":null,"abstract":"<div><h3>Background</h3><div>Intracerebral hemorrhage (ICH) often impacts patient white matter. However, preclinically, the effects of ICH are mostly studied in rodents with sparse white matter. This study used a lobar porcine ICH model to examine differences in the effects of ICH on white and gray matter as well as the role of the iron chelator deferoxamine (DFX), on attenuation of such injury.</div></div><div><h3>Methods</h3><div>This two-part study was performed in piglets. Firstly, piglets had a needle (Sham) or 2.5 ml blood injection (ICH) and were euthanized at day 3. Secondly, animals were treated with vehicle or DFX after ICH and were euthanized at day 3. White and gray matter edema, the number of oligodendrocytes (mature and immature) and neurons, and the number of Perls' (iron), ferritin and heme oxygenase (HO)-1 positive cells were examined.</div></div><div><h3>Results</h3><div>At day 3, ICH induced greater edema formation in white than gray matter. This marked white matter edema was associated with a loss of mature, but not immature, oligodendrocytes. ICH also induced neuronal death in gray matter. There were also marked increases in Perls', ferritin and HO-1 positive cells after ICH in both white and gray matter, but significantly more in the former. DFX attenuated ICH-induced brain edema in white but not gray matter and this was associated with increased survival of mature oligodendrocytes. DFX also increased survival of neurons in the gray matter and it reduced the number of Perls', ferritin and HO-1 positive cells in both tissue types.</div></div><div><h3>Conclusions</h3><div>While there were commonalities in perihematomal changes between white and gray matter after ICH, there was greater edema in white matter which may be linked to the susceptibility of mature oligodendrocytes to ICH injury. Similarly, while DFX reduced perihematomal iron overload in both white and gray matter, it only significantly reduced edema in white matter where it increased the number of mature oligodendrocytes.</div></div>","PeriodicalId":12246,"journal":{"name":"Experimental Neurology","volume":"383 ","pages":"Article 115041"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142566616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.1016/j.expneurol.2024.115036
Yajun Qian , Junjie Wang , Jiarui Chen , Weibo Lin , Huimin Shen , Yuanjian Fang , Wenhua Yu
Subarachnoid hemorrhage (SAH) is a severe neurological condition characterized by high morbidity and mortality. The unfavorable prognosis of SAH is closely associated with early brain injury (EBI) and delayed cerebral ischemia (DCI), wherein thrombin plays a role as part of the secondary injury components following hemorrhage in these two pathological processes. Additionally, thrombin contributes to disruptions in the circulation of cerebrospinal fluid (CSF), thereby giving rise to a spectrum of sequelae following SAH, including cerebral edema, hydrocephalus, cognitive impairments, and depressive symptoms. This review aims to provide a comprehensive understanding of the pathological role of thrombin in EBI, DCI, and CSF circulation following SAH, with a specific focus on its impact on the glymphatic-meningeal lymphatic system—a crucial mechanism for waste clearance and neurohomeostatic regulation. Additionally, this review offers an overview of current pharmacological interventions and treatment modalities targeting pathogenic mechanisms, aiming to mitigate brain injury and promote neurological recovery post-SAH.
{"title":"Multifaceted role of thrombin in subarachnoid hemorrhage: Focusing on cerebrospinal fluid circulation disorder","authors":"Yajun Qian , Junjie Wang , Jiarui Chen , Weibo Lin , Huimin Shen , Yuanjian Fang , Wenhua Yu","doi":"10.1016/j.expneurol.2024.115036","DOIUrl":"10.1016/j.expneurol.2024.115036","url":null,"abstract":"<div><div>Subarachnoid hemorrhage (SAH) is a severe neurological condition characterized by high morbidity and mortality. The unfavorable prognosis of SAH is closely associated with early brain injury (EBI) and delayed cerebral ischemia (DCI), wherein thrombin plays a role as part of the secondary injury components following hemorrhage in these two pathological processes. Additionally, thrombin contributes to disruptions in the circulation of cerebrospinal fluid (CSF), thereby giving rise to a spectrum of sequelae following SAH, including cerebral edema, hydrocephalus, cognitive impairments, and depressive symptoms. This review aims to provide a comprehensive understanding of the pathological role of thrombin in EBI, DCI, and CSF circulation following SAH, with a specific focus on its impact on the glymphatic-meningeal lymphatic system—a crucial mechanism for waste clearance and neurohomeostatic regulation. Additionally, this review offers an overview of current pharmacological interventions and treatment modalities targeting pathogenic mechanisms, aiming to mitigate brain injury and promote neurological recovery post-SAH.</div></div>","PeriodicalId":12246,"journal":{"name":"Experimental Neurology","volume":"383 ","pages":"Article 115036"},"PeriodicalIF":4.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142563639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The lateral hypothalamic region (LH) has been identified as a key region for arousal regulation, yet the specific cell types and underlying mechanisms are not fully understood. While neurons expressing orexins (OX) are considered the primary wake-promoting population in the LH, their loss does not reduce daily wake levels, suggesting the presence of additional wake-promoting populations. In this regard, we recently discovered that a non-OX cell group in the LH, marked by the expression of neurotensin (Nts), could powerfully drive wakefulness. Activation of these NtsLH neurons elicits rapid arousal from non-rapid eye movement (NREM) sleep and produces uninterrupted wakefulness for several hours in mice. However, it remains unknown if these neurons are necessary for spontaneous wakefulness and what their precise role is in the initiation and maintenance of this state. To address these questions, we first examined the activity dynamics of the NtsLH population across sleep-wake behavior using fiber photometry. We find that NtsLH neurons are more active during wakefulness, and their activity increases concurrently with, but does not precede, wake-onset. We then selectively destroyed the NtsLH neurons using a diphtheria-toxin-based conditional ablation method, which significantly reduced wake amounts and mean duration of wake bouts and increased the EEG delta power during wakefulness. These findings demonstrate a crucial role for NtsLH neurons in maintaining normal arousal levels, and their loss may be associated with chronic sleepiness in mice.
{"title":"Regulation of wakefulness by neurotensin neurons in the lateral hypothalamus","authors":"Fumito Naganuma , Mudasir Khanday , Sathyajit Sai Bandaru , Whidul Hasan , Kyosuke Hirano , Takeo Yoshikawa , Ramalingam Vetrivelan","doi":"10.1016/j.expneurol.2024.115035","DOIUrl":"10.1016/j.expneurol.2024.115035","url":null,"abstract":"<div><div>The lateral hypothalamic region (LH) has been identified as a key region for arousal regulation, yet the specific cell types and underlying mechanisms are not fully understood. While neurons expressing orexins (OX) are considered the primary wake-promoting population in the LH, their loss does not reduce daily wake levels, suggesting the presence of additional wake-promoting populations. In this regard, we recently discovered that a non-OX cell group in the LH, marked by the expression of neurotensin (Nts), could powerfully drive wakefulness. Activation of these Nts<sup>LH</sup> neurons elicits rapid arousal from non-rapid eye movement (NREM) sleep and produces uninterrupted wakefulness for several hours in mice. However, it remains unknown if these neurons are necessary for spontaneous wakefulness and what their precise role is in the initiation and maintenance of this state. To address these questions, we first examined the activity dynamics of the Nts<sup>LH</sup> population across sleep-wake behavior using fiber photometry. We find that Nts<sup>LH</sup> neurons are more active during wakefulness, and their activity increases concurrently with, but does not precede, wake-onset. We then selectively destroyed the Nts<sup>LH</sup> neurons using a diphtheria-toxin-based conditional ablation method, which significantly reduced wake amounts and mean duration of wake bouts and increased the EEG delta power during wakefulness. These findings demonstrate a crucial role for Nts<sup>LH</sup> neurons in maintaining normal arousal levels, and their loss may be associated with chronic sleepiness in mice.</div></div>","PeriodicalId":12246,"journal":{"name":"Experimental Neurology","volume":"383 ","pages":"Article 115035"},"PeriodicalIF":4.6,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142557502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.expneurol.2024.115037
Yubin Wu , Ruonan Gao , Qintao Huang , Cuihua Huang , Lijing Wang , Lu Lin , Guanlian He , Kejun Wu , Xiaoying Liu , Xiaohong Liu , Libin Liu
Recurrent non-severe hypoglycemia (RH) in diabetes is an independent risk factor for cognitive dysfunction. However, the mechanisms and potential therapeutic strategies remain poorly understood. In this study, we aimed to elucidate the mechanisms underlying RH-induced diabetic cognitive impairment. We investigated the effects of RH on lactate metabolism and cognitive function in male C57BL/6 J diabetic mice. After RH, diabetic mice showed decreased brain lactate and adenosine triphosphate levels, decreased expression of lactate transporter proteins MCT1 and MCT4, increased neuroapoptosis, and decreased astrocyte glycolysis in vitro. This was accompanied by increased neuronal mitochondrial reactive oxygen species levels, decreased mitochondrial COX IV activity, impaired mitochondrial morphology and function, impaired synaptic morphology, and decreased expression of synaptic plasticity proteins. Intraperitoneal lactic acid injection improved lactate transport restored neuronal mitochondrial morphology and function, upregulated synaptic plasticity proteins brain-derived neurotrophic factor and early growth response 1, enhanced synaptic ultrastructure, and ultimately improved cognitive dysfunction following RH in diabetic mice. These findings provide insights into the prevention and treatment of cognitive dysfunction in patients with diabetes mellitus caused by RH.
{"title":"Lactate supplementation after hypoglycemia alleviates cognitive dysfunction induced by recurrent non-severe hypoglycemia in diabetic mice","authors":"Yubin Wu , Ruonan Gao , Qintao Huang , Cuihua Huang , Lijing Wang , Lu Lin , Guanlian He , Kejun Wu , Xiaoying Liu , Xiaohong Liu , Libin Liu","doi":"10.1016/j.expneurol.2024.115037","DOIUrl":"10.1016/j.expneurol.2024.115037","url":null,"abstract":"<div><div>Recurrent non-severe hypoglycemia (RH) in diabetes is an independent risk factor for cognitive dysfunction. However, the mechanisms and potential therapeutic strategies remain poorly understood. In this study, we aimed to elucidate the mechanisms underlying RH-induced diabetic cognitive impairment. We investigated the effects of RH on lactate metabolism and cognitive function in male C57BL/6 J diabetic mice. After RH, diabetic mice showed decreased brain lactate and adenosine triphosphate levels, decreased expression of lactate transporter proteins MCT1 and MCT4, increased neuroapoptosis, and decreased astrocyte glycolysis in vitro. This was accompanied by increased neuronal mitochondrial reactive oxygen species levels, decreased mitochondrial COX IV activity, impaired mitochondrial morphology and function, impaired synaptic morphology, and decreased expression of synaptic plasticity proteins. Intraperitoneal lactic acid injection improved lactate transport restored neuronal mitochondrial morphology and function, upregulated synaptic plasticity proteins brain-derived neurotrophic factor and early growth response 1, enhanced synaptic ultrastructure, and ultimately improved cognitive dysfunction following RH in diabetic mice. These findings provide insights into the prevention and treatment of cognitive dysfunction in patients with diabetes mellitus caused by RH.</div></div>","PeriodicalId":12246,"journal":{"name":"Experimental Neurology","volume":"383 ","pages":"Article 115037"},"PeriodicalIF":4.6,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142557499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.expneurol.2024.115038
Yan Xu , Xuesong Wang , Xiaolei Zhou , Wenhui Zeng , Jiayi Yuan , Junsong Ye
Spinal cord injury (SCI) is a relatively common and lethal dangerous disease of the central nervous system, for which there is a lack of effective clinical treatments. It has been found that mesenchymal stem cell-derived exosomes (MSC-Exos) play a key role in alleviating SCI through mechanisms such as regulating the microenvironment, promoting angiogenesis, and facilitating axonal regeneration. However, the drawbacks of natural exosomes, such as low yield, weak activity, and low targeting ability, limit their clinical applications. In recent years, MSCs-Exos have gradually become a research hotspot for treating SCI through miRNA modulation, combined hydrogel, and preculture. In addition, exosomes as good biocompatible drugs, nucleic acid, and other delivery carriers have shown a broad application prospect in treating SCI. This article summarizes the pathogenesis of SCI and the research progress of MSC-Exos in the treatment of SCI in recent years, and provides a systematic review of the mechanisms of MSC exosomes and their combination with different modalities in the treatment of SCI.
{"title":"Multiple strategies enhance the efficacy of MSC-Exos transplantation for spinal cord injury","authors":"Yan Xu , Xuesong Wang , Xiaolei Zhou , Wenhui Zeng , Jiayi Yuan , Junsong Ye","doi":"10.1016/j.expneurol.2024.115038","DOIUrl":"10.1016/j.expneurol.2024.115038","url":null,"abstract":"<div><div>Spinal cord injury (SCI) is a relatively common and lethal dangerous disease of the central nervous system, for which there is a lack of effective clinical treatments. It has been found that mesenchymal stem cell-derived exosomes (MSC-Exos) play a key role in alleviating SCI through mechanisms such as regulating the microenvironment, promoting angiogenesis, and facilitating axonal regeneration. However, the drawbacks of natural exosomes, such as low yield, weak activity, and low targeting ability, limit their clinical applications. In recent years, MSCs-Exos have gradually become a research hotspot for treating SCI through miRNA modulation, combined hydrogel, and preculture. In addition, exosomes as good biocompatible drugs, nucleic acid, and other delivery carriers have shown a broad application prospect in treating SCI. This article summarizes the pathogenesis of SCI and the research progress of MSC-Exos in the treatment of SCI in recent years, and provides a systematic review of the mechanisms of MSC exosomes and their combination with different modalities in the treatment of SCI.</div></div>","PeriodicalId":12246,"journal":{"name":"Experimental Neurology","volume":"383 ","pages":"Article 115038"},"PeriodicalIF":4.6,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142557500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.expneurol.2024.115039
Jaison Cucarian , Pamela Raposo , Romana Vavrek , Antoinette Nguyen , Brooklynn Nelson , Philippe Monnier , Abel Torres-Espin , Keith Fenrich , Karim Fouad
Following spinal cord injury (SCI), inflammation is associated with the exacerbation of damage to spinal tissue. Consequently, managing inflammation during the acute and subacute phases is a common target in SCI treatment. However, inflammation may also induce potential benefits, including the stimulation of neuroplasticity and repair. This positive role of inflammation in spinal cord healing and functional recovery is not fully understood. To address this knowledge gap, we examined the effects of two common anti-inflammatory medications, Diphenhydramine and Methylprednisolone, on the efficacy of rehabilitative motor training on recovery from subacute cervical SCI in adult rats. Training depends critically on neuroplasticity thus if inflammation is a key regulator, we propose that anti-inflammatory drugs will reduce subsequent recovery. Both drugs were administered orally over one month, alongside task-specific reaching and grasping training.
After treatment, no substantial changes in motor recovery or lesion size between the treated and control groups were observed. Treated animals also did not show any discernible changes in sensory function or anxiety-like behavior. Taken together, our data indicate that the prolonged use of these anti-inflammatory agents at commonly used doses did not profoundly impact recovery following an SCI. Therefore, considering earlier reports of the benefits of pro-inflammatory stimuli on plasticity, further studies in this area are imperative to elucidate the true impact of treating inflammation and its implications for recovery after spinal cord injuries.
{"title":"No impact of anti-inflammatory medication on inflammation-driven recovery following cervical spinal cord injury in rats","authors":"Jaison Cucarian , Pamela Raposo , Romana Vavrek , Antoinette Nguyen , Brooklynn Nelson , Philippe Monnier , Abel Torres-Espin , Keith Fenrich , Karim Fouad","doi":"10.1016/j.expneurol.2024.115039","DOIUrl":"10.1016/j.expneurol.2024.115039","url":null,"abstract":"<div><div>Following spinal cord injury (SCI), inflammation is associated with the exacerbation of damage to spinal tissue. Consequently, managing inflammation during the acute and subacute phases is a common target in SCI treatment. However, inflammation may also induce potential benefits, including the stimulation of neuroplasticity and repair. This positive role of inflammation in spinal cord healing and functional recovery is not fully understood. To address this knowledge gap, we examined the effects of two common anti-inflammatory medications, Diphenhydramine and Methylprednisolone, on the efficacy of rehabilitative motor training on recovery from subacute cervical SCI in adult rats. Training depends critically on neuroplasticity thus if inflammation is a key regulator, we propose that anti-inflammatory drugs will reduce subsequent recovery. Both drugs were administered orally over one month, alongside task-specific reaching and grasping training.</div><div>After treatment, no substantial changes in motor recovery or lesion size between the treated and control groups were observed. Treated animals also did not show any discernible changes in sensory function or anxiety-like behavior. Taken together, our data indicate that the prolonged use of these anti-inflammatory agents at commonly used doses did not profoundly impact recovery following an SCI. Therefore, considering earlier reports of the benefits of pro-inflammatory stimuli on plasticity, further studies in this area are imperative to elucidate the true impact of treating inflammation and its implications for recovery after spinal cord injuries.</div></div>","PeriodicalId":12246,"journal":{"name":"Experimental Neurology","volume":"383 ","pages":"Article 115039"},"PeriodicalIF":4.6,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142557501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}