P2-11-03. TMS over the contralateral primary visual cortex induces cortico-cortical inhibition in the primary motor cortex

2019 ◽  
Vol 130 (10) ◽  
pp. e220
Author(s):  
Ryutaro Hayashi ◽  
Katsuya Ogata ◽  
Hisato Nakazono ◽  
Shozo Tobimatsu
Keyword(s):  
Visual Cortex ◽  
Motor Cortex ◽  
Primary Visual Cortex ◽  
Primary Motor Cortex ◽  
Cortical Inhibition

scholarly journals Intermittent Theta Burst Stimulation to the Primary Motor Cortex Reduces Cortical Inhibition: A TMS-EEG Study

2021 ◽  
Vol 11 (9) ◽  
pp. 1114
Author(s):  
Zhongfei Bai ◽  
Jiaqi Zhang ◽  
Kenneth N. K. Fong
Keyword(s):  
Visual Cortex ◽  
Motor Cortex ◽  
Primary Visual Cortex ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Motor Area ◽  
Cortical Inhibition ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Theta Burst

Introduction: The aim of this study was to reveal the effects of intermittent theta burst stimulation (iTBS) in modulating cortical networks using transcranial magnetic stimulation and electroencephalography (TMS-EEG) recording. Methods: Eighteen young adults participated in our study and received iTBS to the primary motor cortex (M1), supplementary motor area, and the primary visual cortex in three separate sessions. A finger tapping task and ipsilateral single-pulse TMS-EEG recording for the M1 were administrated before and after iTBS in each session. The effects of iTBS in motor performance and TMS-evoked potentials (TEPs) were investigated. Results: The results showed that iTBS to the M1, but not supplementary motor area or the primary visual cortex, significantly reduced the N100 amplitude of M1 TEPs in bilateral hemispheres (p = 0.019), with a more prominent effect in the contralateral hemisphere than in the stimulated hemisphere. Moreover, only iTBS to the M1 decreased global mean field power (corrected ps < 0.05), interhemispheric signal propagation (t = 2.53, p = 0.030), and TMS-induced early α-band synchronization (p = 0.020). Conclusion: Our study confirmed the local and remote after-effects of iTBS in reducing cortical inhibition in the M1. TMS-induced oscillations after iTBS for changed cortical excitability in patients with various neurological and psychiatric conditions are worth further exploration.

High-intensity Interval Exercise Promotes Motor Cortex Disinhibition and Early Motor Skill Consolidation

2017 ◽  
Vol 29 (4) ◽  
pp. 593-604 ◽  
Author(s):  
Ellen L. Stavrinos ◽  
James P. Coxon
Keyword(s):  
Motor Cortex ◽  
Motor Skill ◽  
High Intensity ◽  
Primary Motor Cortex ◽  
Long Term Potentiation ◽  
Exercise Group ◽  
Cortical Inhibition ◽  
Motor Memory ◽  
Control Group ◽  
High Intensity Interval

Gamma-aminobutyric acid (GABA) inhibition shapes motor cortex output, gates synaptic plasticity in the form of long-term potentiation, and plays an important role in motor learning. Remarkably, recent studies have shown that acute cardiovascular exercise can improve motor memory, but the cortical mechanisms are not completely understood. We investigated whether an acute bout of lower-limb high-intensity interval (HIT) exercise could promote motor memory formation in humans through changes in cortical inhibition within the hand region of the primary motor cortex. We used TMS to assess the input–output relationship, along with inhibition involving GABAA and GABAB receptors. Measures were obtained before and after a 20-min session of HIT cycling (exercise group) or rest (control group). We then had the same participants learn a new visuomotor skill and perform a retention test 5 hr later in the absence of sleep. No differences were found in corticomotor excitability or GABAB inhibition; however, synaptic GABAA inhibition was significantly reduced for the exercise group but not the control group. HIT exercise was found to enhance motor skill consolidation. These findings link modification of GABA to improved motor memory consolidation after HIT exercise and suggest that the beneficial effects of exercise on consolidation might not be dependent on sleep.

scholarly journals Primary visual cortex injury produces loss of inhibitory neurons and long-term visual circuit dysfunction

2020 ◽  
Author(s):  
Jan C. Frankowski ◽  
Andrzej T. Foik ◽  
Jiana R. Machhor ◽  
David C. Lyon ◽  
Robert F. Hunt
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Traumatic Injury ◽  
Cortical Inhibition ◽  
Inhibitory Neurons ◽  
List Type ◽  
V1 Neurons ◽  
Adult Mice ◽  
Brain Injured ◽  
The Impact

SummaryPrimary sensory areas of the mammalian neocortex have a remarkable degree of plasticity, allowing neural circuits to adapt to dynamic environments. However, little is known about the effect of traumatic brain injury on visual system function. Here we applied a mild focal contusion injury to primary visual cortex (V1) in adult mice. We found that, although V1 was largely intact in brain-injured mice, there was a reduction in the number of inhibitory interneurons that extended into deep cortical layers. In general, we found a preferential reduction of interneurons located in superficial layers, near the impact site, while interneurons positioned in deeper layers were better preserved. Three months after injury, V1 neurons showed dramatically reduced responses to visual stimuli and weaker orientation selectivity and tuning, consistent with the loss of cortical inhibition. Our results demonstrate that V1 neurons no longer robustly and stably encode visual input following a mild traumatic injury.HighlightsInhibitory neurons are lost throughout brain injured visual cortexVisually-evoked potentials are severely degraded after injuryInjured V1 neurons show weaker selectivity and tuning consistent with reduced interneurons

scholarly journals Intersectional, anterograde transsynaptic targeting of the neurons receiving monosynaptic inputs from two upstream regions

2021 ◽  
Author(s):  
Takuma Kitanishi ◽  
Mariko Tashiro ◽  
Naomi Kitanishi ◽  
Kenji Mizuseki
Keyword(s):  
Gene Expression ◽  
Visual Cortex ◽  
Motor Cortex ◽  
Primary Visual Cortex ◽  
Dorsal Striatum ◽  
Systemic Delivery ◽  
Adeno Associated Virus ◽  
Virus Serotype ◽  
Serotype 1 ◽  
The Brain

A brain region typically receives inputs from multiple upstream areas. However, currently, no method is available to selectively access neurons that receive monosynaptic inputs from two upstream regions. Here, we devised a method to genetically label such neurons in mice by combining the anterograde transsynaptic spread of adeno-associated virus serotype 1 (AAV1) with intersectional gene expression. Injections of AAV1s expressing either Cre or Flpo recombinases and the Cre/Flpo double-dependent AAV into two upstream regions and the downstream region, respectively, were used to label the postsynaptic neurons receiving inputs from the two upstream regions. We demonstrated this labelling in two distinct circuits: the retina/primary visual cortex to the superior colliculus and the bilateral motor cortex to the dorsal striatum. Systemic delivery of the intersectional AAV allowed for unbiased detection of the labelled neurons throughout the brain. This strategy may help analyse the interregional integration of information in the brain.

scholarly journals Coding strategy for surface luminance switches in the primary visual cortex of the awake monkey

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Yi Yang ◽  
Tian Wang ◽  
Yang Li ◽  
Weifeng Dai ◽  
Guanzhong Yang ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Object Identification ◽  
Cortical Inhibition ◽  
Neural Dynamics ◽  
Neural Responses ◽  
Efficient Coding ◽  
Edge Contrast ◽  
Non Local ◽  
Coding Strategy

AbstractBoth surface luminance and edge contrast of an object are essential features for object identification. However, cortical processing of surface luminance remains unclear. In this study, we aim to understand how the primary visual cortex (V1) processes surface luminance information across its different layers. We report that edge-driven responses are stronger than surface-driven responses in V1 input layers, but luminance information is coded more accurately by surface responses. In V1 output layers, the advantage of edge over surface responses increased eight times and luminance information was coded more accurately at edges. Further analysis of neural dynamics shows that such substantial changes for neural responses and luminance coding are mainly due to non-local cortical inhibition in V1’s output layers. Our results suggest that non-local cortical inhibition modulates the responses elicited by the surfaces and edges of objects, and that switching the coding strategy in V1 promotes efficient coding for luminance.

scholarly journals Substantively Lowered Levels of Pantothenic Acid (Vitamin B5) in Several Regions of the Human Brain in Parkinson’s Disease Dementia

Metabolites ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 569
Author(s):  
Melissa Scholefield ◽  
Stephanie J. Church ◽  
Jingshu Xu ◽  
Stefano Patassini ◽  
Nigel M. Hooper ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Motor Cortex ◽  
Substantia Nigra ◽  
Primary Visual Cortex ◽  
Entorhinal Cortex ◽  
Pantothenic Acid ◽  
Middle Temporal Gyrus ◽  
Cingulate Gyrus ◽  
Middle Temporal ◽  
Vitamin B5

Pantothenic acid (vitamin B5) is an essential trace nutrient required for the synthesis of coenzyme A (CoA). It has previously been shown that pantothenic acid is significantly decreased in multiple brain regions in both Alzheimer’s disease (ADD) and Huntington’s disease (HD). The current investigation aimed to determine whether similar changes are also present in cases of Parkinson’s disease dementia (PDD), another age-related neurodegenerative condition, and whether such perturbations might occur in similar regions in these apparently different diseases. Brain tissue was obtained from nine confirmed cases of PDD and nine controls with a post-mortem delay of 26 h or less. Tissues were acquired from nine regions that show high, moderate, or low levels of neurodegeneration in PDD: the cerebellum, motor cortex, primary visual cortex, hippocampus, substantia nigra, middle temporal gyrus, medulla oblongata, cingulate gyrus, and pons. A targeted ultra–high performance liquid chromatography—tandem mass spectrometry (UHPLC-MS/MS) approach was used to quantify pantothenic acid in these tissues. Pantothenic acid was significantly decreased in the cerebellum (p = 0.008), substantia nigra (p = 0.02), and medulla (p = 0.008) of PDD cases. These findings mirror the significant decreases in the cerebellum of both ADD and HD cases, as well as the substantia nigra, putamen, middle frontal gyrus, and entorhinal cortex of HD cases, and motor cortex, primary visual cortex, hippocampus, middle temporal gyrus, cingulate gyrus, and entorhinal cortex of ADD cases. Taken together, these observations indicate a common but regionally selective disruption of pantothenic acid levels across PDD, ADD, and HD.

scholarly journals Shared and distinct transcriptomic cell types across neocortical areas

2017 ◽  
Author(s):  
Bosiljka Tasic ◽  
Zizhen Yao ◽  
Kimberly A. Smith ◽  
Lucas Graybuck ◽  
Thuc Nghi Nguyen ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Motor Cortex ◽  
Single Cell ◽  
Primary Visual Cortex ◽  
Cortical Cell ◽  
Cell Types ◽  
Rna Seq ◽  
Mouse Cortex ◽  
Single Cell Rna Sequencing ◽  
Cortical Regions

ABSTRACTNeocortex contains a multitude of cell types segregated into layers and functionally distinct regions. To investigate the diversity of cell types across the mouse neocortex, we analyzed 12,714 cells from the primary visual cortex (VISp), and 9,035 cells from the anterior lateral motor cortex (ALM) by deep single-cell RNA-sequencing (scRNA-seq), identifying 116 transcriptomic cell types. These two regions represent distant poles of the neocortex and perform distinct functions. We define 50 inhibitory transcriptomic cell types, all of which are shared across both cortical regions. In contrast, 49 of 52 excitatory transcriptomic types were found in either VISp or ALM, with only three present in both. By combining single cell RNA-seq and retrograde labeling, we demonstrate correspondence between excitatory transcriptomic types and their region-specific long-range target specificity. This study establishes a combined transcriptomic and projectional taxonomy of cortical cell types from functionally distinct regions of the mouse cortex.

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