Ageing and the human brain

2020 ◽  
pp. 170-182
Author(s):  
Verena Heise ◽  
Enikő Zsoldos ◽  
Klaus P. Ebmeier
Keyword(s):  
In Vivo Imaging ◽  
Allostatic Load ◽  
Public Health Medicine ◽  
Causal Factors ◽  
Stress Markers ◽  
Age Related ◽  
Brain Changes ◽  
Heuristic Device ◽  
The Brain

There is little doubt that the brain changes with time, and all research in psychiatry is predicated on holding age constant in comparing groups of patients or estimating the effect sizes of causal factors. Nevertheless, relatively little is known about the mechanisms that are responsible for translating time into ageing. This chapter tries, after an overview of the principal mechanisms involved in biological ageing, to summarize the age-related changes observable in brains in vivo and to demonstrate the types of investigations that may cast light on such mechanisms in the future. A useful heuristic device to order the multiple potential causes of ageing is the chronic stress–allostatic load model, widely employed in epidemiology, public health medicine, and health psychology. In vivo imaging provides a method to test the translation of intermediate stress markers, such as vascular risk, metabolic syndrome, or allostatic load, into predictors of age-related brain changes.

Development of Radioiodinated Benzofuran Derivatives for in Vivo Imaging of Prion Deposits in the Brain

2019 ◽  
Vol 5 (12) ◽  
pp. 2003-2013 ◽  
Author(s):  
Takeshi Fuchigami ◽  
Masao Kawasaki ◽  
Ryusuke Koyama ◽  
Mari Nakaie ◽  
Takehiro Nakagaki ◽  
...  
Keyword(s):  
In Vivo Imaging ◽  
The Brain

scholarly journals Emergence Of Consciousness And Qualia From A Complex Brain

Folia Medica ◽  
2014 ◽  
Vol 56 (4) ◽  
pp. 289-296
Author(s):  
Jakob Korf
Keyword(s):  
System Theory ◽  
General System ◽  
Resolution Power ◽  
Brain Functions ◽  
Scientific Exploration ◽  
Brain Changes ◽  
Higher Brain Functions ◽  
The Brain

Abstract Qualia are private conscious experiences of which the associated feelings can be reported to other people. Whether qualia are amenable to scientific exploration has often been questioned, which is challenged by the present article. The following arguments are given: 1. the configuration of the brain changes continuously and irreversibly, because of genetic and environmental influences and interhuman communication; 2. qualia and consciousness are processes, rather than states; 3. private feelings, including those associated with qualia, should be positioned in the context of a personal brain as being developed during life; 4. consciousness and qualia should be understood in the context of general system theory, thus concluding that isolated, in vitro, properties of neurons and other brain constituents might marginally contribute to the understanding of higher brain functions, mind or qualia; 5. current in vivo approaches have too little resolution power - in terms of space and time - to delineate individual and subjective brain processes. When subtle personalized properties of the nervous system can be assessed in vivo or in vitro, qualia can scientifically be investigated. We discuss some approaches to overcome these barriers.

Novel quinoxaline derivatives for in vivo imaging of β-amyloid plaques in the brain

2011 ◽  
Vol 21 (14) ◽  
pp. 4193-4196 ◽  
Author(s):  
Mengchao Cui ◽  
Masahiro Ono ◽  
Hiroyuki Kimura ◽  
Boli Liu ◽  
Hideo Saji
Keyword(s):  
In Vivo Imaging ◽  
Amyloid Plaques ◽  
Quinoxaline Derivatives ◽  
Β Amyloid ◽  
The Brain

scholarly journals In vivo imaging of structural, metabolic and functional brain changes in glaucoma

2019 ◽  
Vol 14 (3) ◽  
pp. 446 ◽  
Author(s):  
KevinC. Chan ◽  
Anisha Kasi ◽  
MuneebA. Faiq
Keyword(s):  
In Vivo Imaging ◽  
Functional Brain ◽  
Brain Changes

scholarly journals Potential caveats of putative microglia-specific markers for assessment of age-related cerebrovascular neuroinflammation

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Pedram Honarpisheh ◽  
Juneyoung Lee ◽  
Anik Banerjee ◽  
Maria P. Blasco-Conesa ◽  
Parisa Honarpisheh ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Ex Vivo ◽  
Myeloid Cells ◽  
Amyloid Angiopathy ◽  
Future Studies ◽  
Age Related ◽  
In Vivo Animal Models ◽  
Intermediate Expression ◽  
The Brain

Abstract Background The ability to distinguish resident microglia from infiltrating myeloid cells by flow cytometry-based surface phenotyping is an important technique for examining age-related neuroinflammation. The most commonly used surface markers for the identification of microglia include CD45 (low-intermediate expression), CD11b, Tmem119, and P2RY12. Methods In this study, we examined changes in expression levels of these putative microglia markers in in vivo animal models of stroke, cerebral amyloid angiopathy (CAA), and aging as well as in an ex vivo LPS-induced inflammation model. Results We demonstrate that Tmem119 and P2RY12 expression is evident within both CD45int and CD45high myeloid populations in models of stroke, CAA, and aging. Interestingly, LPS stimulation of FACS-sorted adult microglia suggested that these brain-resident myeloid cells can upregulate CD45 and downregulate Tmem119 and P2RY12, making them indistinguishable from peripherally derived myeloid populations. Importantly, our findings show that these changes in the molecular signatures of microglia can occur without a contribution from the other brain-resident or peripherally sourced immune cells. Conclusion We recommend future studies approach microglia identification by flow cytometry with caution, particularly in the absence of the use of a combination of markers validated for the specific neuroinflammation model of interest. The subpopulation of resident microglia residing within the “infiltrating myeloid” population, albeit small, may be functionally important in maintaining immune vigilance in the brain thus should not be overlooked in neuroimmunological studies.

scholarly journals GPCR-Based Dopamine Sensors—A Detailed Guide to Inform Sensor Choice for In Vivo Imaging

2020 ◽  
Vol 21 (21) ◽  
pp. 8048
Author(s):  
Marie A. Labouesse ◽  
Reto B. Cola ◽  
Tommaso Patriarchi
Keyword(s):  
In Vivo Imaging ◽  
Dynamic Range ◽  
New Techniques ◽  
Experimental Parameters ◽  
Sensor Properties ◽  
Molecular Specificity ◽  
Freely Behaving ◽  
The Brain ◽  
Da Release

Understanding how dopamine (DA) encodes behavior depends on technologies that can reliably monitor DA release in freely-behaving animals. Recently, red and green genetically encoded sensors for DA (dLight, GRAB-DA) were developed and now provide the ability to track release dynamics at a subsecond resolution, with submicromolar affinity and high molecular specificity. Combined with rapid developments in in vivo imaging, these sensors have the potential to transform the field of DA sensing and DA-based drug discovery. When implementing these tools in the laboratory, it is important to consider there is not a ‘one-size-fits-all’ sensor. Sensor properties, most importantly their affinity and dynamic range, must be carefully chosen to match local DA levels. Molecular specificity, sensor kinetics, spectral properties, brightness, sensor scaffold and pharmacology can further influence sensor choice depending on the experimental question. In this review, we use DA as an example; we briefly summarize old and new techniques to monitor DA release, including DA biosensors. We then outline a map of DA heterogeneity across the brain and provide a guide for optimal sensor choice and implementation based on local DA levels and other experimental parameters. Altogether this review should act as a tool to guide DA sensor choice for end-users.

Radioiodinated Flavones for in Vivo Imaging of β-Amyloid Plaques in the Brain

2005 ◽  
Vol 48 (23) ◽  
pp. 7253-7260 ◽  
Author(s):  
Masahiro Ono ◽  
Naoko Yoshida ◽  
Kenichi Ishibashi ◽  
Mamoru Haratake ◽  
Yasushi Arano ◽  
...  
Keyword(s):  
In Vivo Imaging ◽  
Amyloid Plaques ◽  
Β Amyloid ◽  
The Brain

scholarly journals T2 heterogeneity as an in vivo marker of microstructural integrity in medial temporal lobe subfields in ageing and mild cognitive impairment

2020 ◽  
Author(s):  
Alfie R. Wearn ◽  
Volkan Nurdal ◽  
Esther Saunders-Jennings ◽  
Michael J. Knight ◽  
Christopher R. Madan ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Learning Task ◽  
Quantitative Mri ◽  
Associate Learning ◽  
Age Related ◽  
Brain Changes

ABSTRACTA better understanding of early brain changes that precede loss of independence in diseases like Alzheimer’s disease (AD) is critical for development of disease-modifying therapies. Quantitative MRI, such as T2 relaxometry, can identify microstructural changes relevant to early stages of pathology. Recent evidence suggests heterogeneity of T2 may be a more informative measure of early pathology than absolute T2. Here we test whether T2 markers of brain integrity precede the volume changes we know are present in established AD and whether such changes are most marked in medial temporal lobe (MTL) subfields known to be most affected early in AD. We show that T2 heterogeneity was greater in people with mild cognitive impairment (MCI; n=49) compared to healthy older controls (n=99) in all MTL subfields, but this increase was greatest in MTL cortices, and smallest in dentate gyrus. This reflects the spatio-temporal progression of neurodegeneration in AD. T2 heterogeneity in the entorhinal cortex also predicted cognitive decline over a year in people with MCI, where measures of volume or T2 in any other subfield or whole hippocampus could not. Increases in T2 heterogeneity in MTL cortices may reflect localised pathological change and may present as one of the earliest detectible brain changes prior to atrophy. Finally, we describe a mechanism by which memory, as measured by accuracy and reaction time on a paired associate learning task, deteriorates with age. Age-related memory deficits were explained in part by lower subfield volumes, which in turn were directly associated with greater T2 heterogeneity. We propose that tissue with high T2 heterogeneity represents extant tissue at risk of permanent damage but with the potential for therapeutic rescue. This has implications for early detection of neurodegenerative disease.

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