scholarly journals Influence of anatomical features of different brain regions on the spatial localization of fiber photometry signals

2021 ◽  
Author(s):  
Cinzia Montinaro ◽  
Marco Pisanello ◽  
Marco Bianco ◽  
Barbara Spagnolo ◽  
Filippo Pisano ◽  
...  
Keyword(s):  
Optical Properties ◽  
Region Of Interest ◽  
Local Variation ◽  
Brain Regions ◽  
Fluorescence Signal ◽  
In Vivo Detection ◽  
Actual Shape ◽  
The Brain ◽  
Cellular Types

Fiber photometry is widely used in neuroscience labs for in vivo detection of functional fluorescence from optical indicators of neuronal activity with a simple optical fiber. The fiber is commonly placed next to the region of interest to both excite and collect the fluorescence signal. However, the path of both excitation and fluorescence photons is altered by the uneven optical properties of the brain, due to local variation of the refractive index, different cellular types, densities and shapes. Nonetheless, the effect of the local anatomy on the actual shape and extent of the volume of tissue that interfaces with the fiber has received little attention so far. To fill this gap, we measured the size and shape of fiber photometry efficiency field in the primary motor and somatosensory cortex, in the hippocampus and in the striatum of the mouse brain, highlighting how their substructures determine the detected signal and the depth at which photons can be mined. Importantly, we show that the information on the spatial expression of the fluorescent probes alone is not sufficient to account for the contribution of local subregions to the overall collected signal, and it must be combined with the optical properties of the tissue adjacent to the fiber tip.

Noninvasive Detection of Misfolded Proteins in the Brain Using [11C]BF-227 PET

2013 ◽  
pp. 438-445
Author(s):  
Nobuyuki Okamura ◽  
Shozo Furumoto ◽  
Manabu Tashiro ◽  
Katsutoshi Furukawa ◽  
Hiroyuki Arai ◽  
...  
Keyword(s):  
Protein Misfolding ◽  
Protein A ◽  
Lewy Bodies ◽  
Protein Aggregates ◽  
Brain Regions ◽  
Postmortem Brain ◽  
In Vivo Detection ◽  
Misfolding Diseases ◽  
The Brain

Alzheimer’s disease (AD) and many other neurodegenerative disorders belong to the family of protein misfolding diseases. These diseases are characterized by the deposition of insoluble protein aggregates containing an enriched ß-sheet structure. To evaluate PET amyloid-imaging tracer [11C]BF-227 as an agent for in vivo detection of various kinds of misfolded protein, a [11C]BF-227 PET study was performed in patients with various protein misfolding diseases, including AD, frontotemporal dementia (FTD), dementia with Lewy bodies (DLB), sporadic Creutzfeldt-Jakob disease (sCJD) and Gerstmann-Sträussler-Scheinker disease (GSS). BF-227 binds to ß-amyloid fibrils with high affinity. Most of the AD patients showed prominent retention of [11C]BF-227 in the neocortex. In addition, neocortical retention of BF-227 was observed in the subjects with mild cognitive impairment who converted to AD during follow-up. DLB patients had elevated [11C]BF-227 uptake in the neocortex. However, FTD and sCJD patients showed no cortical retention of [11C]BF-227. Patients with multiple system atrophy had elevated BF-227 binding in the putamen. Finally, GSS patients had elevated BF-227 uptake in the cerebellum and other brain regions. This chapter confirms that BF-227 can selectively bind to a-synuclein and prion protein deposits using postmortem brain samples. Based on these findings, [11C]BF-227 is not necessarily specific for ß-amyloid in AD patients. However, this tracer could be used to detect various types of protein aggregates in the brain.

Noninvasive Detection of Misfolded Proteins in the Brain Using [11C]BF-227 PET

2011 ◽  
pp. 212-219
Author(s):  
Nobuyuki Okamura ◽  
Shozo Furumoto ◽  
Manabu Tashiro ◽  
Katsutoshi Furukawa ◽  
Hiroyuki Arai ◽  
...  
Keyword(s):  
Protein Misfolding ◽  
Protein A ◽  
Lewy Bodies ◽  
Protein Aggregates ◽  
Brain Regions ◽  
Postmortem Brain ◽  
In Vivo Detection ◽  
Misfolding Diseases ◽  
The Brain

Alzheimer’s disease (AD) and many other neurodegenerative disorders belong to the family of protein misfolding diseases. These diseases are characterized by the deposition of insoluble protein aggregates containing an enriched ß-sheet structure. To evaluate PET amyloid-imaging tracer [11C]BF-227 as an agent for in vivo detection of various kinds of misfolded protein, a [11C]BF-227 PET study was performed in patients with various protein misfolding diseases, including AD, frontotemporal dementia (FTD), dementia with Lewy bodies (DLB), sporadic Creutzfeldt-Jakob disease (sCJD) and Gerstmann-Sträussler-Scheinker disease (GSS). BF-227 binds to ß-amyloid fibrils with high affinity. Most of the AD patients showed prominent retention of [11C]BF-227 in the neocortex. In addition, neocortical retention of BF-227 was observed in the subjects with mild cognitive impairment who converted to AD during follow-up. DLB patients had elevated [11C]BF-227 uptake in the neocortex. However, FTD and sCJD patients showed no cortical retention of [11C]BF-227. Patients with multiple system atrophy had elevated BF-227 binding in the putamen. Finally, GSS patients had elevated BF-227 uptake in the cerebellum and other brain regions. This chapter confirms that BF-227 can selectively bind to a-synuclein and prion protein deposits using postmortem brain samples. Based on these findings, [11C]BF-227 is not necessarily specific for ß-amyloid in AD patients. However, this tracer could be used to detect various types of protein aggregates in the brain.

scholarly journals A probabilistic atlas of the human ventral tegmental area (VTA) based on 7 Tesla MRI data

2021 ◽  
Vol 226 (4) ◽  
pp. 1155-1167 ◽  
Author(s):  
Anne C. Trutti ◽  
Laura Fontanesi ◽  
Martijn J. Mulder ◽  
Pierre-Louis Bazin ◽  
Bernhard Hommel ◽  
...  
Keyword(s):  
Ventral Tegmental Area ◽  
Region Of Interest ◽  
Reward Processing ◽  
7 Tesla ◽  
Subcortical Structures ◽  
7 Tesla Mri ◽  
Subcortical Nuclei ◽  
Ventral Tegmental ◽  
The Brain

AbstractFunctional magnetic resonance imaging (fMRI) BOLD signal is commonly localized by using neuroanatomical atlases, which can also serve for region of interest analyses. Yet, the available MRI atlases have serious limitations when it comes to imaging subcortical structures: only 7% of the 455 subcortical nuclei are captured by current atlases. This highlights the general difficulty in mapping smaller nuclei deep in the brain, which can be addressed using ultra-high field 7 Tesla (T) MRI. The ventral tegmental area (VTA) is a subcortical structure that plays a pivotal role in reward processing, learning and memory. Despite the significant interest in this nucleus in cognitive neuroscience, there are currently no available, anatomically precise VTA atlases derived from 7 T MRI data that cover the full region of the VTA. Here, we first provide a protocol for multimodal VTA imaging and delineation. We then provide a data description of a probabilistic VTA atlas based on in vivo 7 T MRI data.

scholarly journals Mapping the common and distinct neural correlates of visual, rule and motor conflict

2020 ◽  
Author(s):  
Bryony Goulding Mew ◽  
Darije Custovic ◽  
Eyal Soreq ◽  
Romy Lorenz ◽  
Ines Violante ◽  
...  
Keyword(s):  
Region Of Interest ◽  
Neural Correlates ◽  
Brain Regions ◽  
Control Mechanisms ◽  
Activation Patterns ◽  
The Common ◽  
Full Factorial ◽  
The Brain ◽  
Categorical Scale ◽  
Conflict Types

AbstractFlexible behaviour requires cognitive-control mechanisms to efficiently resolve conflict between competing information and alternative actions. Whether a global neural resource mediates all forms of conflict or this is achieved within domainspecific systems remains debated. We use a novel fMRI paradigm to orthogonally manipulate rule, response and stimulus-based conflict within a full-factorial design. Whole-brain voxelwise analyses show that activation patterns associated with these conflict types are distinct but partially overlapping within Multiple Demand Cortex (MDC), the brain regions that are most commonly active during cognitive tasks. Region of interest analysis shows that most MDC sub-regions are activated for all conflict types, but to significantly varying levels. We propose that conflict resolution is an emergent property of distributed brain networks, the functional-anatomical components of which place on a continuous, not categorical, scale from domain-specialised to domain general. MDC brain regions place towards one end of that scale but display considerable functional heterogeneity.

A novel platform for in vivo detection of cytokine release within discrete brain regions

2018 ◽  
Vol 71 ◽  
pp. 18-22 ◽  
Author(s):  
Kaixin Zhang ◽  
Michael V. Baratta ◽  
Guozhen Liu ◽  
Matthew G. Frank ◽  
Nathan R. Leslie ◽  
...  
Keyword(s):  
Brain Regions ◽  
Cytokine Release ◽  
In Vivo Detection

scholarly journals Microglial exosomes facilitate α-synuclein transmission in Parkinson’s disease

Brain ◽  
2020 ◽  
Vol 143 (5) ◽  
pp. 1476-1497 ◽  
Author(s):  
Min Guo ◽  
Jian Wang ◽  
Yanxin Zhao ◽  
Yiwei Feng ◽  
Sida Han ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Protein Aggregation ◽  
Brain Regions ◽  
Dependent Manner ◽  
Nigrostriatal Pathway ◽  
Stereotaxic Injection ◽  
Promising Therapeutic Target ◽  
The Brain

Abstract Accumulation of neuronal α-synuclein is a prominent feature in Parkinson’s disease. More recently, such abnormal protein aggregation has been reported to spread from cell to cell and exosomes are considered as important mediators. The focus of such research, however, has been primarily in neurons. Given the increasing recognition of the importance of non-cell autonomous-mediated neurotoxicity, it is critical to investigate the contribution of glia to α-synuclein aggregation and spread. Microglia are the primary phagocytes in the brain and have been well-documented as inducers of neuroinflammation. How and to what extent microglia and their exosomes impact α-synuclein pathology has not been well delineated. We report here that when treated with human α-synuclein preformed fibrils, exosomes containing α-synuclein released by microglia are fully capable of inducing protein aggregation in the recipient neurons. Additionally, when combined with microglial proinflammatory cytokines, these exosomes further increased protein aggregation in neurons. Inhibition of exosome synthesis in microglia reduced α-synuclein transmission. The in vivo significance of these exosomes was demonstrated by stereotaxic injection of exosomes isolated from α-synuclein preformed fibrils treated microglia into the mouse striatum. Phosphorylated α-synuclein was observed in multiple brain regions consistent with their neuronal connectivity. These animals also exhibited neurodegeneration in the nigrostriatal pathway in a time-dependent manner. Depleting microglia in vivo dramatically suppressed the transmission of α-synuclein after stereotaxic injection of preformed fibrils. Mechanistically, we report here that α-synuclein preformed fibrils impaired autophagy flux by upregulating PELI1, which in turn, resulted in degradation of LAMP2 in activated microglia. More importantly, by purifying microglia/macrophage derived exosomes in the CSF of Parkinson’s disease patients, we confirmed the presence of α-synuclein oligomer in CD11b+ exosomes, which were able to induce α-synuclein aggregation in neurons, further supporting the translational aspect of this study. Taken together, our study supports the view that microglial exosomes contribute to the progression of α-synuclein pathology and therefore, they may serve as a promising therapeutic target for Parkinson’s disease.

scholarly journals Mixed Amphiphilic Polymeric Nanoparticles of Chitosan, Poly(vinyl alcohol) and Poly(methyl methacrylate) for Intranasal Drug Delivery: A Preliminary In Vivo Study

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4496 ◽  
Author(s):  
Inbar Schlachet ◽  
Hen Moshe Halamish ◽  
Alejandro Sosnik
Keyword(s):  
Methyl Methacrylate ◽  
Vinyl Alcohol ◽  
Sodium Tripolyphosphate ◽  
Brain Regions ◽  
Poly Vinyl Alcohol ◽  
Drug Bioavailability ◽  
Poly Methyl Methacrylate ◽  
Target Organs ◽  
The Brain

Intranasal (i.n.) administration became an alternative strategy to bypass the blood–brain barrier and improve drug bioavailability in the brain. The main goal of this work was to preliminarily study the biodistribution of mixed amphiphilic mucoadhesive nanoparticles made of chitosan-g-poly(methyl methacrylate) and poly(vinyl alcohol)-g-poly(methyl methacrylate) and ionotropically crosslinked with sodium tripolyphosphate in the brain after intravenous (i.v.) and i.n. administration to Hsd:ICR mice. After i.v. administration, the highest nanoparticle accumulation was detected in the liver, among other peripheral organs. After i.n. administration of a 10-times smaller nanoparticle dose, the accumulation of the nanoparticles in off-target organs was much lower than after i.v. injection. In particular, the accumulation of the nanoparticles in the liver was 20 times lower than by i.v. When brains were analyzed separately, intravenously administered nanoparticles accumulated mainly in the “top” brain, reaching a maximum after 1 h. Conversely, in i.n. administration, nanoparticles were detected in the “bottom” brain and the head (maximum reached after 2 h) owing to their retention in the nasal mucosa and could serve as a reservoir from which the drug is released and transported to the brain over time. Overall, results indicate that i.n. nanoparticles reach similar brain bioavailability, though with a 10-fold smaller dose, and accumulate in off-target organs to a more limited extent and only after redistribution through the systemic circulation. At the same time, both administration routes seem to lead to differential accumulation in brain regions, and thus, they could be beneficial in the treatment of different medical conditions.

scholarly journals A Review of Neurotransmitters Sensing Methods for Neuro-Engineering Research

2019 ◽  
Vol 9 (21) ◽  
pp. 4719 ◽  
Author(s):  
Shimwe Dominique Niyonambaza ◽  
Praveen Kumar ◽  
Paul Xing ◽  
Jessy Mathault ◽  
Paul De Koninck ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Ongoing Research ◽  
Engineering Research ◽  
Detection Techniques ◽  
In Vivo Detection ◽  
Low Concentrations ◽  
The Subject ◽  
The Brain

Neurotransmitters as electrochemical signaling molecules are essential for proper brain function and their dysfunction is involved in several mental disorders. Therefore, the accurate detection and monitoring of these substances are crucial in brain studies. Neurotransmitters are present in the nervous system at very low concentrations, and they mixed with many other biochemical molecules and minerals, thus making their selective detection and measurement difficult. Although numerous techniques to do so have been proposed in the literature, neurotransmitter monitoring in the brain is still a challenge and the subject of ongoing research. This article reviews the current advances and trends in neurotransmitters detection techniques, including in vivo sampling and imaging techniques, electrochemical and nano-object sensing techniques for in vitro and in vivo detection, as well as spectrometric, analytical and derivatization-based methods mainly used for in vitro research. The document analyzes the strengths and weaknesses of each method, with the aim to offer selection guidelines for neuro-engineering research.

A Novel Imaging Probe for In Vivo Detection of Neuritic and Diffuse Amyloid Plaques in the Brain

2004 ◽  
Vol 24 (2) ◽  
pp. 247-256 ◽  
Author(s):  
Nobuyuki Okamura ◽  
Takahiro Suemoto ◽  
Tsuyoshi Shiomitsu ◽  
Masako Suzuki ◽  
Hiroshi Shimadzu ◽  
...  
Keyword(s):  
Amyloid Plaques ◽  
Imaging Probe ◽  
In Vivo Detection ◽  
The Brain

In vivo detection of hepatitis C virus (HCV) RNA in the brain in a case of encephalitis: evidence for HCV neuroinvasion

2008 ◽  
Vol 15 (3) ◽  
pp. 214-218 ◽  
Author(s):  
F. Seifert ◽  
T. Struffert ◽  
M. Hildebrandt ◽  
I. Blümcke ◽  
W. Brück ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hcv Rna ◽  
In Vivo Detection ◽  
The Brain
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