scholarly journals The effects of locomotion on sensory-evoked haemodynamic responses in the cortex of awake mice

2021 ◽  
Author(s):  
Beth Eyre ◽  
Kira Shaw ◽  
Paul Sharp ◽  
Luke Boorman ◽  
Llywelyn Lee ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Imaging Spectroscopy ◽  
Sensory Cortex ◽  
Cerebral Haemodynamics ◽  
Brain Physiology ◽  
Whisker Stimulation ◽  
Stimulation Experiments ◽  
Set Up ◽  
Sensory Evoked ◽  
The Brain

Investigating neurovascular coupling in awake rodents is becoming ever more popular due, in part, to our increasing knowledge of the profound impacts that anaesthesia can have upon brain physiology. Although awake imaging brings with it many advantages, we still do not fully understand how voluntary locomotion during imaging affects sensory-evoked haemodynamic responses. In this study we investigated how evoked haemodynamic responses can be affected by the amount and timing of locomotion. Using an awake imaging set up, we used 2D-Optical Imaging Spectroscopy (2D-OIS) to measure changes in cerebral haemodynamics within the sensory cortex of the brain during either 2s whisker stimulation or spontaneous (no whisker stimulation) experiments, whilst animals could walk on a spherical treadmill. We show that locomotion alters haemodynamic responses. The amount and timing of locomotion relative to whisker stimulation is important, and can significantly impact sensory-evoked haemodynamic responses. If locomotion occurred before or during whisker stimulation, the amplitude of the stimulus-evoked haemodynamic response was significantly altered. Therefore, monitoring of locomotion during awake imaging is necessary to ensure that conclusions based on comparisons of evoked haemodynamic responses (e.g., between control and disease groups) are not confounded by the effects of locomotion.

Neuronal basis of optical imaging signals in sensory cortex

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S683-S683 ◽  
Author(s):  
Anna Devor ◽  
Istvan Ulbert ◽  
Andrew K Dunn ◽  
Suresh N Narayanan ◽  
Stephanie R Jones ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Sensory Cortex

Revision Targeted Muscle Reinnervation Improves Secondary Pain Insult in an Upper Extremity Amputee: A Case Report

Hand ◽  
2021 ◽  
pp. 155894472199246
Author(s):  
David D. Rivedal ◽  
Meng Guo ◽  
James Sanger ◽  
Aaron Morgan
Keyword(s):  
Neuropathic Pain ◽  
Peripheral Nerves ◽  
Nerve Biopsy ◽  
Sensory Cortex ◽  
Denervated Muscle ◽  
Unique Case ◽  
Targeted Muscle Reinnervation ◽  
Muscle Reinnervation ◽  
And Function ◽  
The Brain

Targeted muscle reinnervation (TMR) has been shown to improve phantom and neuropathic pain in both the acute and chronic amputee population. Through rerouting of major peripheral nerves into a newly denervated muscle, TMR harnesses the plasticity of the brain, helping to revert the sensory cortex back toward the preinsult state, effectively reducing pain. We highlight a unique case of an above-elbow amputee for sarcoma who was initially treated with successful transhumeral TMR. Following inadvertent nerve biopsy of a TMR coaptation site, his pain returned, and he was unable to don his prosthetic. Revision of his TMR to a more proximal level was performed, providing improved pain and function of the amputated arm. This is the first report to highlight the concept of secondary neuroplasticity and successful proximal TMR revision in the setting of multiple insults to the same extremity.

scholarly journals Optical Imaging of Beta-Amyloid Plaques in Alzheimer’s Disease

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 255
Author(s):  
Ziyi Luo ◽  
Hao Xu ◽  
Liwei Liu ◽  
Tymish Y. Ohulchanskyy ◽  
Junle Qu
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Optical Imaging ◽  
Imaging Techniques ◽  
High Sensitivity ◽  
Pathological Feature ◽  
Promising Tool ◽  
Abnormal Accumulation ◽  
Accumulation Mechanism ◽  
The Brain

Alzheimer’s disease (AD) is a multifactorial, irreversible, and incurable neurodegenerative disease. The main pathological feature of AD is the deposition of misfolded β-amyloid protein (Aβ) plaques in the brain. The abnormal accumulation of Aβ plaques leads to the loss of some neuron functions, further causing the neuron entanglement and the corresponding functional damage, which has a great impact on memory and cognitive functions. Hence, studying the accumulation mechanism of Aβ in the brain and its effect on other tissues is of great significance for the early diagnosis of AD. The current clinical studies of Aβ accumulation mainly rely on medical imaging techniques, which have some deficiencies in sensitivity and specificity. Optical imaging has recently become a research hotspot in the medical field and clinical applications, manifesting noninvasiveness, high sensitivity, absence of ionizing radiation, high contrast, and spatial resolution. Moreover, it is now emerging as a promising tool for the diagnosis and study of Aβ buildup. This review focuses on the application of the optical imaging technique for the determination of Aβ plaques in AD research. In addition, recent advances and key operational applications are discussed.

There are no A1 and A2 astrocytes in brain

2021 ◽  
Author(s):  
Shuang-qi Gao
Keyword(s):  
Endothelial Cells ◽  
Single Cell ◽  
Rna Sequencing ◽  
Cell Sorting ◽  
Reactive Astrocytes ◽  
Marker Genes ◽  
Set Up ◽  
The Brain

Abstract Objectives The subsets of astrocytes in the brain have not been fully elucidated. Using bulk RNA sequencing, reactive astrocytes were divided into A1 versus A2. However, using single-cell RNAseq (ScRNAseq), astrocytes were divided into over two subsets. Our aim was to set up the correspondence between the fluorescent-activated cell sorting (FACS)-bulk RNAseq and ScRNAseq data. Results We found that most of reactive astrocytes (RAs) marker genes were expressed in endothelial cells but not in astrocytes, suggesting those marker genes are not suitable for astrocytic activation. The absence of A1 and A2 astrocytes in the brain.

scholarly journals Regeneration, Plasticity, and Induced Molecular Programs in Adult Zebrafish Brain

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mehmet Ilyas Cosacak ◽  
Christos Papadimitriou ◽  
Caghan Kizil
Keyword(s):  
Neural Plasticity ◽  
Molecular Mechanisms ◽  
Clinical Settings ◽  
Regenerative Capacity ◽  
Zebrafish Brain ◽  
Aquatic Vertebrates ◽  
Neural Stem Progenitor Cells ◽  
Set Up ◽  
Regenerative Therapies ◽  
The Brain

Regenerative capacity of the brain is a variable trait within animals. Aquatic vertebrates such as zebrafish have widespread ability to renew their brains upon damage, while mammals have—if not none—very limited overall regenerative competence. Underlying cause of such a disparity is not fully evident; however, one of the reasons could be activation of peculiar molecular programs, which might have specific roles after injury or damage, by the organisms that regenerate. If this hypothesis is correct, then there must be genes and pathways that (a) are expressed only after injury or damage in tissues, (b) are biologically and functionally relevant to restoration of neural tissue, and (c) are not detected in regenerating organisms. Presence of such programs might circumvent the initial detrimental effects of the damage and subsequently set up the stage for tissue redevelopment to take place by modulating the plasticity of the neural stem/progenitor cells. Additionally, if transferable, those “molecular mechanisms of regeneration” could open up new avenues for regenerative therapies of humans in clinical settings. This review focuses on the recent studies addressing injury/damage-induced molecular programs in zebrafish brain, underscoring the possibility of the presence of genes that could be used as biomarkers of neural plasticity and regeneration.

Monopolar and bipolar stimulation of the brain

1962 ◽  
Vol 203 (2) ◽  
pp. 371-373 ◽  
Author(s):  
Paul Stark ◽  
Giovanni Fazio ◽  
Eugene S. Boyd
Keyword(s):  
Current Density ◽  
Bipolar Electrode ◽  
Wire Electrode ◽  
Bipolar Stimulation ◽  
Monopolar Stimulation ◽  
Stimulation Experiments ◽  
Self Stimulation ◽  
The Brain ◽  
Rate Of Response ◽  
Stimulation Of

Intracranial self-stimulation experiments in the dog using a two-wire electrode, with each wire used as a monopolar electrode and the combination as a bipolar electrode, show that monopolar stimulation may produce either a higher or a lower rate of response than that produced by bipolar stimulation. A theoretical consideration of the changes in current density around the electrode when it is changed from a monopolar to a bipolar electrode shows that such differences are to be expected. The exact location of the structure being stimulated with reference to the two electrode tips will determine whether the structure is subjected to a higher current density on monopolar or on bipolar stimulation.

scholarly journals Active information maintenance in working memory by a sensory cortex

2018 ◽  
Author(s):  
Xiaoxing Zhang ◽  
Wenjun Yan ◽  
Wenliang Wang ◽  
Hongmei Fan ◽  
Ruiqing Hou ◽  
...  
Keyword(s):  
Working Memory ◽  
Piriform Cortex ◽  
Delay Period ◽  
Sensory Cortex ◽  
Critical Function ◽  
Impaired Performance ◽  
Anterior Piriform Cortex ◽  
Electrophysiological Recordings ◽  
Dual Task Paradigm ◽  
The Brain

SummaryWorking memory is a critical function of the brain to maintain and manipulate information over delay periods of seconds. Sensory areas have been implicated in working memory; however, it is debated whether the delay-period activity of sensory regions is actively maintaining information or passively reflecting top-down inputs. We hereby examined the anterior piriform cortex, an olfactory cortex, in head-fixed mice performing a series of olfactory working memory tasks. Information maintenance is necessary in these tasks, especially in a dual-task paradigm in which mice are required to perform another distracting task while actively maintaining information during the delay period. Optogenetic suppression of the piriform cortex activity during the delay period impaired performance in all the tasks.Furthermore, electrophysiological recordings revealed that the delay-period activity of the anterior piriform cortex encoded odor information with or without the distracting task.Thus, this sensory cortex is critical for active information maintenance in working memory.

Dreaming and the brain: Toward a cognitive neuroscience of conscious states

2000 ◽  
Vol 23 (6) ◽  
pp. 793-842 ◽  
Author(s):  
J. Allan Hobson ◽  
Edward F. Pace-Schott ◽  
Robert Stickgold
Keyword(s):  
Cognitive Neuroscience ◽  
Rem Sleep ◽  
Three Dimensional ◽  
Nrem Sleep ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Brain Physiology ◽  
Neurophysiological Studies ◽  
The Brain

Sleep researchers in different disciplines disagree about how fully dreaming can be explained in terms of brain physiology. Debate has focused on whether REM sleep dreaming is qualitatively different from nonREM (NREM) sleep and waking. A review of psychophysiological studies shows clear quantitative differences between REM and NREM mentation and between REM and waking mentation. Recent neuroimaging and neurophysiological studies also differentiate REM, NREM, and waking in features with phenomenological implications. Both evidence and theory suggest that there are isomorphisms between the phenomenology and the physiology of dreams. We present a three-dimensional model with specific examples from normally and abnormally changing conscious states.

scholarly journals Infragranular barrel cortex activity is enhanced with learning

2012 ◽  
Vol 108 (5) ◽  
pp. 1278-1287 ◽  
Author(s):  
Rebekah L. Ward ◽  
Luke C. Flores ◽  
John F. Disterhoft
Keyword(s):  
Single Unit ◽  
Barrel Cortex ◽  
Eyeblink Conditioning ◽  
Sensory Cortex ◽  
Learning Criterion ◽  
Extracellular Recordings ◽  
Primary Sensory Cortex ◽  
Whisker Stimulation ◽  
Trace Eyeblink Conditioning

The barrel cortex (BC) is essential for the acquisition of whisker-signaled trace eyeblink conditioning and shows learning-related expansion of the trained barrels after the acquisition of a whisker-signaled task. Most previous research examining the role of the BC in learning has focused on anatomic changes in the layer IV representation of the cortical barrels. We studied single-unit extracellular recordings from individual neurons in layers V and VI of the BC as rabbits acquired the whisker-signaled trace eyeblink conditioning task. Neurons in layers V and VI in both conditioned and pseudoconditioned animals robustly responded to whisker stimulation, but neurons in conditioned animals showed a significant enhancement in responsiveness in concert with learning. Learning-related changes in firing rate occurred as early as the day of learning criterion within the infragranular layers of the primary sensory cortex.

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