scholarly journals Volitional Control of Individual Neurons in the Human Brain

2020 ◽  
Author(s):  
Kramay Patel ◽  
Chaim N. Katz ◽  
Suneil K. Kalia ◽  
Milos R. Popovic ◽  
Taufik A. Valiante
Keyword(s):  
Human Brain ◽  
Firing Rate ◽  
Phase Locking ◽  
Brain Structures ◽  
Human Memory ◽  
Skill Learning ◽  
Oscillation Phase ◽  
Improved Performance ◽  
Beta Frequency ◽  
Interconnected Structure

AbstractCan the human brain, a complex interconnected structure of over 80 billion neurons learn to control itself at the most elemental scale – a single neuron. We directly linked the firing rate of a single (direct) neuron to the position of a box on a screen, which participants tried to control. Remarkably, all subjects upregulated the firing rate of the direct neuron in memory structures of their brain. Learning was accompanied by improved performance over trials, simultaneous decorrelation of the direct neuron to local neurons, and direct neuron to beta frequency oscillation phase-locking. Such previously unexplored neuroprosthetic skill learning within memory related brain structures, and associated beta frequency phase-locking implicates the ventral striatum. Our demonstration that humans can volitionally control neuronal activity in mnemonic structures, may provide new ways of probing the function and plasticity of human memory without exogenous stimulation.

scholarly journals First evidence of long-term effects of transcranial pulse stimulation (TPS) on the human brain

2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Eva Matt ◽  
Lisa Kaindl ◽  
Saskia Tenk ◽  
Anicca Egger ◽  
Teodora Kolarova ◽  
...  
Keyword(s):  
Human Brain ◽  
Brain Stimulation ◽  
Longitudinal Design ◽  
Brain Structures ◽  
Brain Network ◽  
Long Term Effects ◽  
Sensorimotor Network ◽  
Functional Brain Network ◽  
Pulse Stimulation

Abstract Background With the high spatial resolution and the potential to reach deep brain structures, ultrasound-based brain stimulation techniques offer new opportunities to non-invasively treat neurological and psychiatric disorders. However, little is known about long-term effects of ultrasound-based brain stimulation. Applying a longitudinal design, we comprehensively investigated neuromodulation induced by ultrasound brain stimulation to provide first sham-controlled evidence of long-term effects on the human brain and behavior. Methods Twelve healthy participants received three sham and three verum sessions with transcranial pulse stimulation (TPS) focused on the cortical somatosensory representation of the right hand. One week before and after the sham and verum TPS applications, comprehensive structural and functional resting state MRI investigations and behavioral tests targeting tactile spatial discrimination and sensorimotor dexterity were performed. Results Compared to sham, global efficiency significantly increased within the cortical sensorimotor network after verum TPS, indicating an upregulation of the stimulated functional brain network. Axial diffusivity in left sensorimotor areas decreased after verum TPS, demonstrating an improved axonal status in the stimulated area. Conclusions TPS increased the functional and structural coupling within the stimulated left primary somatosensory cortex and adjacent sensorimotor areas up to one week after the last stimulation. These findings suggest that TPS induces neuroplastic changes that go beyond the spatial and temporal stimulation settings encouraging further clinical applications.

scholarly journals Cellular resolution anatomical and molecular atlases for prenatal human brains

2021 ◽  
Author(s):  
Song-Lin Ding ◽  
Joshua J. Royall ◽  
Phil Lesnar ◽  
Benjamin A.C. Facer ◽  
Kimberly A. Smith ◽  
...  
Keyword(s):  
Human Brain ◽  
Hippocampal Formation ◽  
Marker Gene ◽  
Brain Structures ◽  
Marker Genes ◽  
Subcortical Structures ◽  
Cellular Resolution ◽  
Reliable Marker ◽  
Human Brains ◽  
Developmental Features

Increasing interest in studies of prenatal human brain development, particularly using new single-cell genomics and anatomical technologies to create cell atlases, creates a strong need for accurate and detailed anatomical reference atlases. In this study, we present two cellular-resolution digital anatomical atlases for prenatal human brain at post-conceptional weeks (PCW) 15 and 21. Both atlases were annotated on sequential Nissl-stained sections covering brain-wide structures on the basis of combined analysis of cytoarchitecture, acetylcholinesterase staining and an extensive marker gene expression dataset. This high information content dataset allowed reliable and accurate demarcation of developing cortical and subcortical structures and their subdivisions. Furthermore, using the anatomical atlases as a guide, spatial expression of 37 and 5 genes from the brains respectively at PCW 15 and 21 was annotated, illustrating reliable marker genes for many developing brain structures. Finally, the present study uncovered several novel developmental features, such as the lack of an outer subventricular zone in the hippocampal formation and entorhinal cortex, and the apparent extension of both cortical (excitatory) and subcortical (inhibitory) progenitors into the prenatal olfactory bulb. These comprehensive atlases provide useful tools for visualization, targeting, imaging and interpretation of brain structures of prenatal human brain, and for guiding and interpreting the next generation of cell census and connectome studies.

Mind and Matter

Mind Shift ◽  
2021 ◽  
pp. 19-31
Author(s):  
John Parrington
Keyword(s):  
Human Brain ◽  
Rene Descartes ◽  
Brain Structures ◽  
Human Mind ◽  
Black Box ◽  
Human Consciousness ◽  
Common Thread ◽  
René Descartes

This chapter discusses different views on the basis of human consciousness. A major problem with much popular speculation about the biological roots of consciousness is that those who advocate a gene-based view of consciousness often appear to have little understanding of modern genetics, while speculation about how brain structures shape that consciousness often bear little resemblance to emerging knowledge about the complexity of an actual human brain. There is a common thread here, which is that idealised genes and brains have been substituted for real ones. Unfortunately, because of this tendency, it is not clear how much we have really advanced forwards from René Descartes and his belief that the human mind was an unknowable entity, or for that matter, the behaviourists with their view that the human mind could be treated as a black box. In contrast, to understand human consciousness, there is a need to understand real genes, real brains, and how these have evolved in humans compared to other species.

scholarly journals GABAA receptors contribute more to rate than temporal coding in the IC of awake mice

2020 ◽  
Vol 123 (1) ◽  
pp. 134-148
Author(s):  
Boris Gourévitch ◽  
Elena J. Mahrt ◽  
Warren Bakay ◽  
Cameron Elde ◽  
Christine V. Portfors
Keyword(s):  
Firing Rate ◽  
Neuronal Response ◽  
Signal Transmission ◽  
Brain Structures ◽  
Temporal Coding ◽  
Model Organisms ◽  
Gabaergic Inhibition ◽  
Response Curves ◽  
Daily Lives ◽  
Complex Sounds

Speech is our most important form of communication, yet we have a poor understanding of how communication sounds are processed by the brain. Mice make great model organisms to study neural processing of communication sounds because of their rich repertoire of social vocalizations and because they have brain structures analogous to humans, such as the auditory midbrain nucleus inferior colliculus (IC). Although the combined roles of GABAergic and glycinergic inhibition on vocalization selectivity in the IC have been studied to a limited degree, the discrete contributions of GABAergic inhibition have only rarely been examined. In this study, we examined how GABAergic inhibition contributes to shaping responses to pure tones as well as selectivity to complex sounds in the IC of awake mice. In our set of long-latency neurons, we found that GABAergic inhibition extends the evoked firing rate range of IC neurons by lowering the baseline firing rate but maintaining the highest probability of firing rate. GABAergic inhibition also prevented IC neurons from bursting in a spontaneous state. Finally, we found that although GABAergic inhibition shaped the spectrotemporal response to vocalizations in a nonlinear fashion, it did not affect the neural code needed to discriminate vocalizations, based either on spiking patterns or on firing rate. Overall, our results emphasize that even if GABAergic inhibition generally decreases the firing rate, it does so while maintaining or extending the abilities of neurons in the IC to code the wide variety of sounds that mammals are exposed to in their daily lives. NEW & NOTEWORTHY GABAergic inhibition adds nonlinearity to neuronal response curves. This increases the neuronal range of evoked firing rate by reducing baseline firing. GABAergic inhibition prevents bursting responses from neurons in a spontaneous state, reducing noise in the temporal coding of the neuron. This could result in improved signal transmission to the cortex.

Virtual Reality—Virtual Brain: Questioning Reality

Leonardo ◽  
2018 ◽  
Vol 51 (5) ◽  
pp. 453-459 ◽  
Author(s):  
Teresa Wennberg
Keyword(s):  
Virtual Reality ◽  
Human Brain ◽  
Cognitive Processes ◽  
Human Memory ◽  
Computer Memory ◽  
Brain Functions ◽  
Multimedia Art ◽  
Individual Human

The author’s multimedia art is inspired by memory and cognitive processes. This paper discusses certain human brain functions, including a reflection on the evolution from individual human memory to collective computer memory and the role of the artist in this vital change.

Shock, Surgery and Cerebral Asymmetry

1970 ◽  
Vol 117 (537) ◽  
pp. 143-148 ◽  
Author(s):  
James Inglis
Keyword(s):  
Side Effects ◽  
Human Brain ◽  
Learning And Memory ◽  
Electroconvulsive Therapy ◽  
Systematic Study ◽  
Memory Function ◽  
Human Memory ◽  
Normal Activity ◽  
Temporal Lobectomy ◽  
Cerebral Asymmetry

The main contention of this paper is that some of the transient side-effects of electroconvulsive therapy on human memory resemble, in kind if not in degree, those more severe and chronic learning defects that are known to appear as an incidental result of temporal lobectomy in man. If this claim can plausibly be supported it would imply a pressing need for the more systematic study of other modes of therapeutically effective ECT that would interfere as little as possible with the normal activity of those parts of the human brain that are essential for adequate learning and memory function.

Short- and Long-range Neural Synchrony in Grapheme–Color Synesthesia

2013 ◽  
Vol 25 (7) ◽  
pp. 1148-1162 ◽  
Author(s):  
Gregor Volberg ◽  
Anna Karmann ◽  
Stefanie Birkner ◽  
Mark W. Greenlee
Keyword(s):  
Long Range ◽  
Visual Processing ◽  
Short Range ◽  
Phase Locking ◽  
Brain Structures ◽  
Neural Synchrony ◽  
Beta Band ◽  
Color Processing ◽  
Processing Stream ◽  
Theta Frequency

Grapheme–color synesthesia is a perceptual phenomenon where single graphemes (e.g., the letter “E”) induce simultaneous sensations of colors (e.g., the color green) that were not objectively shown. Current models disagree as to whether the color sensations arise from increased short-range connectivity between anatomically adjacent grapheme- and color-processing brain structures or from decreased effectiveness of inhibitory long-range connections feeding back into visual cortex. We addressed this issue by examining neural synchrony obtained from EEG activity, in a sample of grapheme–color synesthetes that were presented with color-inducing versus non-color-inducing graphemes. For color-inducing graphemes, the results showed a decrease in the number of long-range couplings in the theta frequency band (4–7 Hz, 280–540 msec) and a concurrent increase of short-range phase-locking within lower beta band (13–20 Hz, 380–420 msec at occipital electrodes). Because the effects were both found in long-range synchrony and later within the visual processing stream, the results support the idea that reduced inhibition is an important factor for the emergence of synesthetic colors.

scholarly journals Antibodies to normal and Alzheimer human brain structures from non-immunised mice of various ages

FEBS Letters ◽  
1987 ◽  
Vol 217 (1) ◽  
pp. 62-64 ◽  
Author(s):  
James Simpson ◽  
Ian H. Milne ◽  
John O. Gardner ◽  
Celia M. Yates ◽  
Keith James ◽  
...  
Keyword(s):  
Human Brain ◽  
Brain Structures
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