Noninvasive disconnection of targeted neuronal circuitry sparing axons of passage and nonneuronal cells

2021 ◽  
pp. 1-11
Author(s):  
Yi Wang ◽  
Matthew J. Anzivino ◽  
Yanrong Zhang ◽  
Edward H. Bertram ◽  
James Woznak ◽  
...  
Keyword(s):  
Neurological Disorders ◽  
Focused Ultrasound ◽  
Focal Epilepsy ◽  
Neuronal Loss ◽  
Brain Regions ◽  
Brain Parenchyma ◽  
The Brain ◽  
Patient Confidence ◽  
Treatment Envelope ◽  
Bbb Opening

OBJECTIVE Surgery can be highly effective for the treatment of medically intractable, neurological disorders, such as drug-resistant focal epilepsy. However, despite its benefits, surgery remains substantially underutilized due to both surgical concerns and nonsurgical impediments. In this work, the authors characterized a noninvasive, nonablative strategy to focally destroy neurons in the brain parenchyma with the goal of limiting collateral damage to nontarget structures, such as axons of passage. METHODS Low-intensity MR-guided focused ultrasound (MRgFUS), together with intravenous microbubbles, was used to open the blood-brain barrier (BBB) in a transient and focal manner in rats. The period of BBB opening was exploited to focally deliver to the brain parenchyma a systemically administered neurotoxin (quinolinic acid) that is well tolerated peripherally and otherwise impermeable to the BBB. RESULTS Focal neuronal loss was observed in targeted areas of BBB opening, including brain regions that are prime objectives for epilepsy surgery. Notably, other structures in the area of neuronal loss, including axons of passage, glial cells, vasculature, and the ventricular wall, were spared with this procedure. CONCLUSIONS These findings identify a noninvasive, nonablative approach capable of disconnecting neural circuitry while limiting the neuropathological consequences that attend other surgical procedures. Moreover, this strategy allows conformal targeting, which could enhance the precision and expand the treatment envelope for treating irregularly shaped surgical objectives located in difficult-to-reach sites. Finally, if this strategy translates to the clinic, the noninvasive nature and specificity of the procedure could positively influence both physician referrals for and patient confidence in surgery for medically intractable neurological disorders.

scholarly journals MR-guided focused ultrasound liquid biopsy enriches circulating biomarkers in patients with brain tumors

2021 ◽  
Author(s):  
Ying Meng ◽  
Christopher B Pople ◽  
Suganth Suppiah ◽  
Maheleth Llinas ◽  
Yuexi Huang ◽  
...  
Keyword(s):  
Liquid Biopsy ◽  
Focused Ultrasound ◽  
Brain Regions ◽  
Specific Protein ◽  
Rank Test ◽  
Open Label ◽  
Isocitrate Dehydrogenase 1 ◽  
Serious Adverse Events ◽  
Before And After ◽  
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Abstract Background Liquid biopsy is promising for early detection, monitoring of response and recurrence of cancer. The blood-brain barrier (BBB) limits the shedding of biomarker, such as cell-free DNA (cfDNA), into the blood, and their detection by conventional assays. Transcranial MR-guided focused ultrasound (MRgFUS) can safely and transiently open the BBB, providing an opportunity for less-invasive access to brain pathology. We hypothesized MRgFUS can enrich the signal of circulating brain-derived biomarkers to aid in liquid biopsy. Methods Nine patients were treated in a prospective single-arm, open-label trial to investigate serial MRgFUS and adjuvant temozolomide combination in patients with glioblastoma (NCT03616860). Blood samples were collected as an exploratory measure within the hours before and after sonication, with control samples from non-brain tumor patients undergoing BBB opening alone (NCT03739905). Results Brain regions averaging 7.8±6.0 cm 3 (range 0.8–23.1 cm 3) were successful treated within 111±39 minutes without any serious adverse events. We found MRgFUS acutely enhanced plasma cfDNA (2.6±1.2 fold, p<0.01, Wilcoxon signed-rank test), neuron-derived extracellular vesicles (3.2±1.9 fold, p<0.01), and brain specific protein S100b (1.4±0.2 fold, p<0.01). Further comparison of the cfDNA methylation profiles suggests a signature that is disease and post-BBB opening specific, in keeping with our hypothesis. We also found cfDNA mutant copies of isocitrate dehydrogenase 1 (IDH1) increased, although this was in only one patient known to harbour the tumor mutation. Conclusions This first-in-human proof-of concept study shows MRgFUS enriches the signal of circulating brain-derived biomarkers, demonstrating the potential of the technology to support liquid biopsy for the brain.

scholarly journals Physical positioning markedly enhances brain transduction after intrathecal AAV9 infusion

2018 ◽  
Vol 4 (11) ◽  
pp. eaau9859 ◽  
Author(s):  
Michael J. Castle ◽  
Yuhsiang Cheng ◽  
Aravind Asokan ◽  
Mark H. Tuszynski
Keyword(s):  
Gene Expression ◽  
Gene Delivery ◽  
Neurological Disorders ◽  
Fold Increase ◽  
Brain Regions ◽  
Intrathecal Administration ◽  
Simple Method ◽  
Virus Serotype ◽  
Cortical Regions ◽  
The Brain

Several neurological disorders may benefit from gene therapy. However, even when using the lead vector candidate for intrathecal administration, adeno-associated virus serotype 9 (AAV9), the strength and distribution of gene transfer to the brain are inconsistent. On the basis of preliminary observations that standard intrathecal AAV9 infusions predominantly drive reporter gene expression in brain regions where gravity might cause cerebrospinal fluid to settle, we tested the hypothesis that counteracting vector “settling” through animal positioning would enhance vector delivery to the brain. When rats are either inverted in the Trendelenburg position or continuously rotated after intrathecal AAV9 infusion, we find (i) a significant 15-fold increase in the number of transduced neurons, (ii) a marked increase in gene delivery to cortical regions, and (iii) superior animal-to-animal consistency of gene expression. Entorhinal, prefrontal, frontal, parietal, hippocampal, limbic, and basal forebrain neurons are extensively transduced: 95% of transduced cells are neurons, and greater than 70% are excitatory. These findings provide a novel and simple method for broad gene delivery to the cortex and are of substantial relevance to translational programs for neurological disorders, including Alzheimer’s disease and related dementias, stroke, and traumatic brain injury.

scholarly journals Ceramide and Related-Sphingolipid Levels Are Not Altered in Disease-Associated Brain Regions of APPSLand APPSL/PS1M146LMouse Models of Alzheimer's Disease: Relationship with the Lack of Neurodegeneration?

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Laurence Barrier ◽  
Bernard Fauconneau ◽  
Anastasia Noël ◽  
Sabrina Ingrand
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Animal Models ◽  
Neuronal Death ◽  
Time Course ◽  
Neuronal Loss ◽  
Brain Regions ◽  
App Processing ◽  
Ceramide Accumulation ◽  
The Brain

There is evidence linking sphingolipid abnormalities, APP processing, and neuronal death in Alzheimer's disease (AD). We previously reported a strong elevation of ceramide levels in the brain of the APPSL/PS1Ki mouse model of AD, preceding the neuronal death. To extend these findings, we analyzed ceramide and related-sphingolipid contents in brain from two other mouse models (i.e., APPSLand APPSL/PS1M146L) in which the time-course of pathology is closer to that seen in most currently available models. Conversely to our previous work, ceramides did not accumulate in disease-associated brain regions (cortex and hippocampus) from both models. However, the APPSL/PS1Ki model is unique for its drastic neuronal loss coinciding with strong accumulation of neurotoxic Aβisoforms, not observed in other animal models of AD. Since there are neither neuronal loss nor toxic Aβspecies accumulation in APPSLmice, we hypothesized that it might explain the lack of ceramide accumulation, at least in this model.

scholarly journals Pharmacodynamic Analysis of Magnetic Resonance Imaging-Monitored Focused Ultrasound-Induced Blood-Brain Barrier Opening for Drug Delivery to Brain Tumors

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Po-Chun Chu ◽  
Wen-Yen Chai ◽  
Han-Yi Hsieh ◽  
Jiun-Jie Wang ◽  
Shiaw-Pyng Wey ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Small Molecule ◽  
Focused Ultrasound ◽  
Therapeutic Agents ◽  
Tumor Treatment ◽  
Target Region ◽  
Pharmacodynamic Analysis ◽  
The Brain ◽  
Bbb Opening

Microbubble-enhanced focused ultrasound (FUS) can enhance the delivery of therapeutic agents into the brain for brain tumor treatment. The purpose of this study was to investigate the influence of brain tumor conditions on the distribution and dynamics of small molecule leakage into targeted regions of the brain after FUS-BBB opening. A total of 34 animals were used, and the process was monitored by 7T-MRI. Evans blue (EB) dye as well as Gd-DTPA served as small molecule substitutes for evaluation of drug behavior. EB was quantified spectrophotometrically. Spin-spin (R1) relaxometry and area under curve (AUC) were measured by MRI to quantify Gd-DTPA. We found that FUS-BBB opening provided a more significant increase in permeability with small tumors. In contrast, accumulation was much higher in large tumors, independent of FUS. The AUC values of Gd-DTPA were well correlated with EB delivery, suggesting that Gd-DTPA was a good indicator of total small-molecule accumulation in the target region. The peripheral regions of large tumors exhibited similar dynamics of small-molecule leakage after FUS-BBB opening as small tumors, suggesting that FUS-BBB opening may have the most significant permeability-enhancing effect on tumor peripheral. This study provides useful information toward designing an optimized FUS-BBB opening strategy to deliver small-molecule therapeutic agents into brain tumors.

scholarly journals Transcriptomic analysis of frontotemporal lobar degeneration with TDP-43 pathology reveals cellular alterations across multiple brain regions

2021 ◽  
Author(s):  
Rahat Hasan ◽  
Jack Humphrey ◽  
Conceicao Bettencourt ◽  
Tammaryn Lashley ◽  
Pietro Fratta ◽  
...  
Keyword(s):  
Gene Expression ◽  
Frontotemporal Lobar Degeneration ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Temporal Cortex ◽  
Neuronal Loss ◽  
Underlying Disease ◽  
Brain Regions ◽  
Neuronal Markers ◽  
The Brain

Frontotemporal lobar degeneration (FTLD) is a group of heterogeneous neurodegenerative disorders affecting the frontal and temporal lobes of the brain. Nuclear loss and cytoplasmic aggregation of the RNA-binding protein TDP-43 represents the major FTLD pathology, known as FTLD-TDP. To date, there is no effective treatment for FTLD-TDP due to an incomplete understanding of the molecular mechanisms underlying disease development. Here we compared post-mortem tissue RNA-seq transcriptomes from the frontal cortex, temporal cortex and cerebellum between 28 controls and 30 FTLD-TDP patients to profile changes in cell-type composition, gene expression and transcript usage. We observed downregulation of neuronal markers in all three regions of the brain, accompanied by upregulation of microglia, astrocytes, and oligodendrocytes, as well as endothelial cells and pericytes, suggesting shifts in both immune activation and within the vasculature. We validate our estimates of neuronal loss using neuropathological atrophy scores and show that neuronal loss in the cortex can be mainly attributed to excitatory neurons, and that increases in microglial and endothelial cell expression are highly correlated with neuronal loss. All our analyses identified a strong involvement of the cerebellum in the neurodegenerative process of FTLD-TDP. Altogether, our data provides a detailed landscape of gene expression alterations to help unravel relevant disease mechanisms in FTLD.

scholarly journals In vivo delivery of a fluorescent FPR2/ALX-targeted probe using focused ultrasound and microbubbles to image activated microglia

2020 ◽  
Vol 1 (5) ◽  
pp. 385-389
Author(s):  
Sophie V. Morse ◽  
Tamara Boltersdorf ◽  
Tiffany G. Chan ◽  
Felicity N. E. Gavins ◽  
James J. Choi ◽  
...  
Keyword(s):  
Neurological Disorders ◽  
Focused Ultrasound ◽  
Imaging Agent ◽  
Targeted Imaging ◽  
Activated Microglia ◽  
The Brain ◽  
In Vivo Delivery

Targeted imaging agent labels activated microglia when delivered into the brain with focused ultrasound and microbubbles – a tool to investigate inflammation in neurological disorders.

scholarly journals Feasibility of ablating brain regions adjacent to the optic nerve while retaining nerve function with focused ultrasound combined with an ultrasound contrast agent

2018 ◽  
Author(s):  
Nathan McDannold ◽  
Yongzhi Zhang ◽  
Chanikarn Power ◽  
Natalia Vykhodtseva
Keyword(s):  
Optic Nerve ◽  
Peripheral Nerves ◽  
Focused Ultrasound ◽  
Ultrasound Contrast Agent ◽  
Brain Regions ◽  
Nerve Function ◽  
Ultrasound Surgery ◽  
Focused Ultrasound Surgery ◽  
Nerve Tracts ◽  
The Brain

The goal of this work will be to investigate the safety of ablating tissue with focused ultrasound adjacent to peripheral nerves or to nerve tracts in the brain. We propose experiments in which we ablate tissue adjacent to the sciatic nerve and the optic nerve/tract in the brain and then evaluate nerve function. These experiments are motivated by two promising targets for focused ultrasound treatment where critical nerve structures need to be protected: prostate cancer and brain tumors. If successful, this work will allow good surgical margins, thereby improving the effectiveness of focused ultrasound surgery and reducing local recurrence.

scholarly journals Claudin-5 binder enhances focused ultrasound-mediated opening in an in vitro blood-brain barrier model

2021 ◽  
Author(s):  
Ratneswary Sutharsan ◽  
Liyu Chen ◽  
Jonathan LF Lee ◽  
Esteban Cruz ◽  
Tishila Palliyaguru ◽  
...  
Keyword(s):  
Cell Line ◽  
Blood Brain Barrier ◽  
Focused Ultrasound ◽  
Brain Barrier ◽  
Sodium Fluorescein ◽  
General Strategy ◽  
Blood Brain ◽  
Barrier Opening ◽  
The Brain ◽  
Bbb Opening

Rationale: The blood-brain barrier (BBB) while functioning as a gatekeeper of the brain, impedes cerebral drug delivery. An emerging technology to overcome this limitation is focused ultrasound (FUS). When FUS interacts with intravenously injected microbubbles (FUS+MB), the BBB opens, transiently allowing the access of therapeutic agents into the brain. However, the ultrasound parameters need to be tightly tuned: when the acoustic pressure is too low there is no opening, and when it is too high, bleeds can occur. We therefore asked whether BBB permeability can be increased by combining FUS+MB with a second modality such that in a clinical setting lower acoustic pressures could be potentially used. Methods: Given that FUS achieves BBB opening by the disruption of tight junction (TJ) proteins such as claudin-5 of brain endothelial cells, we generated a stable MDCK II cell line (eGFP-hCldn5-MDCK II) that expresses fluorescently tagged human claudin-5. Two claudin-5 binders, mC5C2 (a peptide) and cCPEm (a truncated form of an enterotoxin), that have been reported previously to weaken the barrier, were synthesized and assessed for their abilities to enhance the permeability of cellular monolayers. We then performed a comparative analysis of single and combination treatments. Results: We successfully generated a novel cell line that formed functional monolayers as validated by an increased transendothelial electrical resistance (TEER) reading and a low (< 0.2%) permeability to sodium fluorescein (376 Da). We found that the binders exerted a time- and concentration-dependent effect on BBB opening when incubated over an extended period, whereas FUS+MB caused a rapid barrier opening followed by recovery after 12 hours within the tested pressure range. Importantly, preincubation with cCPEm prior to FUS+MB treatment resulted in greater barrier opening compared to either FUS+MB or cCPEm alone as measured by reduced TEER values and an increased permeability to fluorescently labelled 40 kDa dextran (FD40). Conclusion: The data suggest that pre-incubation with clinically suitable binders to TJ proteins may be a general strategy to facilitate safer and more effective ultrasound-mediated BBB opening in cellular and animal systems and potentially also for the treatment of human diseases of the brain.

Modulation of ϐ-amyloid production and fibrillization

2001 ◽  
Vol 67 ◽  
pp. 1-14 ◽  
Author(s):  
David Allsop ◽  
Lance J. Twyman ◽  
Yvonne Davies ◽  
Susan Moore ◽  
Amber York ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Fibrils ◽  
Senile Plaques ◽  
Neurofibrillary Tangle ◽  
Neuronal Loss ◽  
Brain Parenchyma ◽  
Amino Acid Peptide ◽  
Close Relatives ◽  
The Brain

Alzheimer's disease (AD) is the most common cause of dementia in old age and presently affects an estimated 4 million people in the U.S.A. and 0.75 million people in the U.K. It is a relentless, degenerative brain disease, characterized by progressive cognitive impairment. In the final stages of the disease, patients are often bedridden, doubly incontinent and unable to speak or to recognize close relatives. Pathological changes of Alzheimer's disease include extensive neuronal loss and the presence of numerous neurofibrillary tangles and senile plaques in the brain. The senile plaques contain amyloid fibrils derived from a 39-43-amino-acid peptide referred to as ϐ-amyloid or Aϐ. The basic theory of the so-called 'amyloid hypothesis' is that the deposition of aggregated forms of Aϐ in the brain parenchyma triggers a pathological cascade of events that leads to neurofibrillary tangle formation, neuronal loss and the associated dementia [1]. Here we discuss progress towards the identification of inhibitors of Aϐ production and fibrillization.

scholarly journals Neuromodulation with transcranial focused ultrasound

2018 ◽  
Vol 44 (2) ◽  
pp. E14 ◽  
Author(s):  
Jan Kubanek
Keyword(s):  
Focused Ultrasound ◽  
Brain Regions ◽  
Stimulation Parameters ◽  
Cellular Excitability ◽  
Psychiatric Conditions ◽  
Specific Stimulation ◽  
Future Work ◽  
The Brain ◽  
Transcranial Focused Ultrasound

The understanding of brain function and the capacity to treat neurological and psychiatric disorders rest on the ability to intervene in neuronal activity in specific brain circuits. Current methods of neuromodulation incur a tradeoff between spatial focus and the level of invasiveness. Transcranial focused ultrasound (FUS) is emerging as a neuromodulation approach that combines noninvasiveness with focus that can be relatively sharp even in regions deep in the brain. This may enable studies of the causal role of specific brain regions in specific behaviors and behavioral disorders. In addition to causal brain mapping, the spatial focus of FUS opens new avenues for treatments of neurological and psychiatric conditions. This review introduces existing and emerging FUS applications in neuromodulation, discusses the mechanisms of FUS effects on cellular excitability, considers the effects of specific stimulation parameters, and lays out the directions for future work.

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