scholarly journals Bidirectional propagation of low frequency oscillations over the human hippocampal surface

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jonathan K. Kleen ◽  
Jason E. Chung ◽  
Kristin K. Sellers ◽  
Jenny Zhou ◽  
Michael Triplett ◽  
...  
Keyword(s):  
Low Frequency ◽  
Low Frequency Oscillations ◽  
Spatiotemporal Processing ◽  
Propagation Axis ◽  
Theta Frequency ◽  
Temporal Pole ◽  
Scale Network ◽  
Bidirectional Propagation ◽  
Oscillation Frequencies

AbstractThe hippocampus is diversely interconnected with other brain systems along its axis. Cycles of theta-frequency activity are believed to propagate from the septal to temporal pole, yet it is unclear how this one-way route supports the flexible cognitive capacities of this structure. We leveraged novel thin-film microgrid arrays conformed to the human hippocampal surface to track neural activity two-dimensionally in vivo. All oscillation frequencies identified between 1–15 Hz propagated across the tissue. Moreover, they dynamically shifted between two roughly opposite directions oblique to the long axis. This predominant propagation axis was mirrored across participants, hemispheres, and consciousness states. Directionality was modulated in a participant who performed a behavioral task, and it could be predicted by wave amplitude topography over the hippocampal surface. Our results show that propagation directions may thus represent distinct meso-scale network computations, operating along versatile spatiotemporal processing routes across the hippocampal body.

scholarly journals Corrigendum: Long-Lasting Response Changes in Deep Cerebellar Nuclei in vivo Correlate With Low-Frequency Oscillations

2019 ◽  
Vol 13 ◽  
Author(s):  
Letizia Moscato ◽  
Ileana Montagna ◽  
Licia De Propris ◽  
Simona Tritto ◽  
Lisa Mapelli ◽  
...  
Keyword(s):  
Low Frequency ◽  
Cerebellar Nuclei ◽  
Deep Cerebellar Nuclei ◽  
Low Frequency Oscillations

In vivo imaging of spontaneous low-frequency oscillations in cerebral hemodynamics with a digital red-green-blue camera

2017 ◽  
Author(s):  
Afrina Mustari ◽  
Naoki Nakamura ◽  
Izumi Nishidate ◽  
Satoko Kawauchi ◽  
Shunichi Sato ◽  
...  
Keyword(s):  
In Vivo Imaging ◽  
Low Frequency ◽  
Cerebral Hemodynamics ◽  
Low Frequency Oscillations

scholarly journals VIBRATORY SEPARATION OF GRAIN FROM THE EAR: PROBLEMS AND PERSPECTIVES

2020 ◽  
Author(s):  
V.I. Pakhomov ◽  
◽  
S.V. Braginets ◽  
O.N. Bakhchevnikov ◽  
D.V. Rudoy ◽  
...  
Keyword(s):  
High Frequency ◽  
Natural Frequencies ◽  
Low Frequency ◽  
Mechanical Resonance ◽  
High Frequency Oscillations ◽  
Low Frequency Oscillations ◽  
Oscillation Frequencies

The method of vibratory separation of grain from ear is validated in article. It is set that transferring to a stalk with ear low frequency oscillations in the range 18…100 Hz corresponding to natural frequencies of its oscillations are possible to achieve damage of ear or its detachment from a stalk as a result of a resonance. But this interval of oscillation frequencies does not provide separation of grains from ear as does not lead to damage of perular scales. Transmission to ear of high-frequency oscillations in the range 100…14000 Hz matching its natural frequencies of oscillations is perspective for this purpose. The mechanical resonance generate to grain separation owing to break off perular scales from ear can result from such vibratory influence.

scholarly journals Long-Lasting Response Changes in Deep Cerebellar Nuclei in vivo Correlate With Low-Frequency Oscillations

2019 ◽  
Vol 13 ◽  
Author(s):  
Letizia Moscato ◽  
Ileana Montagna ◽  
Licia De Propris ◽  
Simona Tritto ◽  
Lisa Mapelli ◽  
...  
Keyword(s):  
Low Frequency ◽  
Cerebellar Nuclei ◽  
Deep Cerebellar Nuclei ◽  
Low Frequency Oscillations

scholarly journals Changes in electromyographic activity, mechanical power, and relaxation rates following inspiratory ribcage muscle fatigue

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Antonio Sarmento ◽  
Guilherme Fregonezi ◽  
Maria Lira ◽  
Layana Marques ◽  
Francesca Pennati ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Low Frequency ◽  
Mechanical Power ◽  
Electromyographic Activity ◽  
Median Frequency ◽  
Relaxation Rates ◽  
Shortening Velocity ◽  
Inspiratory Muscles ◽  
Underlying Mechanisms

AbstractMuscle fatigue is a complex phenomenon enclosing various mechanisms. Despite technological advances, these mechanisms are still not fully understood in vivo. Here, simultaneous measurements of pressure, volume, and ribcage inspiratory muscle activity were performed non-invasively during fatigue (inspiratory threshold valve set at 70% of maximal inspiratory pressure) and recovery to verify if inspiratory ribcage muscle fatigue (1) leads to slowing of contraction and relaxation properties of ribcage muscles and (2) alters median frequency and high-to-low frequency ratio (H/L). During the fatigue protocol, sternocleidomastoid showed the fastest decrease in median frequency and slowest decrease in H/L. Fatigue was also characterized by a reduction in the relative power of the high-frequency and increase of the low-frequency. During recovery, changes in mechanical power were due to changes in shortening velocity with long-lasting reduction in pressure generation, and slowing of relaxation [i.e., tau (τ), half-relaxation time (½RT), and maximum relaxation rate (MRR)] was observed with no significant changes in contractile properties. Recovery of median frequency was faster than H/L, and relaxation rates correlated with shortening velocity and mechanical power of inspiratory ribcage muscles; however, with different time courses. Time constant of the inspiratory ribcage muscles during fatigue and recovery is not uniform (i.e., different inspiratory muscles may have different underlying mechanisms of fatigue), and MRR, ½RT, and τ are not only useful predictors of inspiratory ribcage muscle recovery but may also share common underlying mechanisms with shortening velocity.

scholarly journals Low-frequency oscillations in cortical level to help diagnose task-specific dystonia

2021 ◽  
pp. 105444
Author(s):  
Chun-Chuan Chen ◽  
Antonella Macerollo ◽  
Hoon-Ming Heng ◽  
Ming-Kuei Lu ◽  
Chon-Haw Tsai ◽  
...  
Keyword(s):  
Low Frequency ◽  
Cortical Level ◽  
Low Frequency Oscillations
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