scholarly journals Gait change in tongue movement

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Donald Derrick ◽  
Bryan Gick
Keyword(s):  
Motor System ◽  
Time Course ◽  
Speech Rate ◽  
Gait Pattern ◽  
Fluctuation Analysis ◽  
Tongue Movement ◽  
Critical Fluctuation ◽  
Movement Rate ◽  
Speech Planning ◽  
Gain Access

AbstractDuring locomotion, humans switch gaits from walking to running, and horses from walking to trotting to cantering to galloping, as they increase their movement rate. It is unknown whether gait change leading to a wider movement rate range is limited to locomotive-type behaviours, or instead is a general property of any rate-varying motor system. The tongue during speech provides a motor system that can address this gap. In controlled speech experiments, using phrases containing complex tongue-movement sequences, we demonstrate distinct gaits in tongue movement at different speech rates. As speakers widen their tongue-front displacement range, they gain access to wider speech-rate ranges. At the widest displacement ranges, speakers also produce categorically different patterns for their slowest and fastest speech. Speakers with the narrowest tongue-front displacement ranges show one stable speech-gait pattern, and speakers with widest ranges show two. Critical fluctuation analysis of tongue motion over the time-course of speech revealed these speakers used greater effort at the beginning of phrases—such end-state-comfort effects indicate speech planning. Based on these findings, we expect that categorical motion solutions may emerge in any motor system, providing that system with access to wider movement-rate ranges.

Mechanisms of Potentiation by Calcium-Calmodulin Kinase II of Postsynaptic Sensitivity in Rat Hippocampal CA1 Neurons

1997 ◽  
Vol 78 (5) ◽  
pp. 2682-2692 ◽  
Author(s):  
Aneil M. Shirke ◽  
Roberto Malinow
Keyword(s):  
Time Course ◽  
Long Term Potentiation ◽  
Similar Process ◽  
Fluctuation Analysis ◽  
Maximal Effect ◽  
Internal Perfusion ◽  
Ca1 Neurons ◽  
Hippocampal Ca1 Neurons ◽  
Calmodulin Kinase ◽  
Hippocampal Ca1

Shirke, Aneil M. and Roberto Malinow. Mechanisms of potentiation by calcium-calmodulin kinase II of postsynaptic sensitivity in rat hippocampal CA1 neurons. J. Neurophysiol. 78: 2682–2692, 1997. Preactivated recombinant α-calcium–calmodulin dependent multifunctional protein kinase II (CaMKII*) was perfused internally into CA1 hippocampal slice neurons to test the effect on synaptic transmission and responses to exogenous application of glutamate analogues. After measurement of baseline transmission, internal perfusion of CaMKII* increased synaptic strength in rat hippocampal neurons and diminished the fraction of synaptic failures. After measurement of baseline responses to applied transmitter, CaMKII* perfusion potentiated responses to kainate but not responses to N-methyl-d-aspartate. Internal perfusion of CaMKII*potentiated the maximal effect of kainate. Potentiation byCaMKII* did not change the time course of responses to kainate, whereas increasing response size by pharmacologically manipulating desensitization or deactivation rate constants significantly altered the time course of responses. Nonstationary fluctuation analysis of responses to kainate showed a decrease in the coefficient of variation after potentiation by CaMKII*. These data support the hypothesis that CaMKII increases postsynaptic responsiveness by increasing the available number of active α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid/kainate channels and suggests that a similar process may occur during the expression of long-term potentiation.

scholarly journals Eye-tracking the time course of distal and global speech rate effects.

2020 ◽  
Vol 46 (10) ◽  
pp. 1148-1163
Author(s):  
Merel Maslowski ◽  
Antje S. Meyer ◽  
Hans Rutger Bosker
Keyword(s):  
Eye Tracking ◽  
Time Course ◽  
Speech Rate ◽  
Rate Effects

Forced Revision in Fast Typing: A Note

1988 ◽  
Vol 40 (3) ◽  
pp. 581-589 ◽  
Author(s):  
L. H. Shaffer
Keyword(s):  
Motor System ◽  
Time Course ◽  
Motor Output ◽  
Motor Programming

Forced revision during transcription was brought about by having the text change suddenly at a preset distance ahead of the current motor output. The adaptiveness of the motor system to change was studied as a function of this trigger distance. Two out of five typists tested were able to assimilate the change with minimum disruption of typing fluency. The timescale of revision by these two appears to be within earlier estimates of the time course of motor programming in normal conditions. It shows some sensitivity to syntax, being larger if the change was triggered within the word rather than in the previous word.

scholarly journals Differences in Glycinergic mIPSCs in the Auditory Brain Stem of Normal and Congenitally Deaf Neonatal Mice

2004 ◽  
Vol 91 (2) ◽  
pp. 1006-1012 ◽  
Author(s):  
Richardson N. Leao ◽  
Sharon Oleskevich ◽  
Hong Sun ◽  
Melissa Bautista ◽  
Robert E.W. Fyffe ◽  
...  
Keyword(s):  
Time Course ◽  
Single Channel ◽  
Fluctuation Analysis ◽  
Electron Microscopic ◽  
Early Postnatal Development ◽  
Fundamental Properties ◽  
Medial Nucleus ◽  
Synaptic Structure ◽  
Auditory Brain Stem ◽  
Brain Slice Preparation

We have investigated the fundamental properties of central auditory glycinergic synapses in early postnatal development in normal and congenitally deaf ( dn/dn) mice. Glycinergic miniature inhibitory postsynaptic currents (mIPSCs) were recorded using patch-clamp methods in neurons from a brain slice preparation of the medial nucleus of the trapezoid body (MNTB), at 12-14 days postnatal age. Our results show a number of significant differences between normal and deaf mice. The frequency of mIPSCs is greater (50%) in deaf versus normal mice. Mean mIPSC amplitude is smaller in deaf mice than in normal mice (mean mIPSC amplitude: deaf, 64 pA; normal, 106 pA). Peak-scaled fluctuation analysis of mIPSCs showed that mean single channel conductance is greater in the deaf mice (deaf, 64 pS; normal, 45 pS). The mean decay time course of mIPSCs is slower in MNTB neurons from deaf mice (mean half-width: deaf, 2.9 ms; normal, 2.3 ms). Light- and electron-microscopic immunolabeling results showed that MNTB neurons from deaf mice have more (30%) inhibitory synaptic sites (postsynaptic gephyrin clusters) than MNTB neurons in normal mice. Our results demonstrate substantial differences in glycinergic transmission in normal and congenitally deaf mice, supporting a role for activity during development in regulating both synaptic structure (connectivity) and the fundamental (quantal) properties of mIPSCs at central glycinergic synapses.

scholarly journals Patch recordings from the electrocytes of Electrophorus electricus. Na currents and PNa/PK variability.

1991 ◽  
Vol 97 (5) ◽  
pp. 1013-1041 ◽  
Author(s):  
S Shenkel ◽  
F J Sigworth
Keyword(s):  
Time Course ◽  
Single Channel ◽  
Reversal Potential ◽  
Fluctuation Analysis ◽  
Open Probability ◽  
Na Currents ◽  
Before And After ◽  
Steady State Inactivation ◽  
K Current ◽  
Reversal Potentials

Sodium currents were recorded in cell-attached and inside-out patches from the innervated membrane of Electrophorus electrocytes. Electrocytes from Sachs and main electric organs were prepared as described by Pasquale et al. (1986. J. Membr. Biol. 93:195.). Maximal currents in the Sachs organ, measured with 1-2 microns diameter patch pipettes and at room temperature, were in the range of 20 to 300 pA (27 patches) and were obtained near +10 mV. This range of current corresponds to approximately 70 to 1,300 channels in a patch. Maximal current in main organ cells also occurred near +10 mV and were in the range of 100 to 400 pA. Delayed K current was observed in a few patches. The inactivation phase of the currents during maintained depolarizations appears to be a single-exponential relaxation. The time constant decreases from 1 ms near -55 mV to a minimum of 0.3 ms near 0 mV, and then gradually increases with stronger depolarization. The mean currents are half inactivated near -90 mV with an apparent voltage dependence of e-fold per 6 mV. No apparent differences were observed in the decay time course or steady-state inactivation of the currents in the same patch before and after excision. From ensemble fluctuation analysis the peak open probability was found to be approximately 0.5 at +25 mV and increased only gradually with larger depolarizations. The single channel conductances were approximately 20 pS with 200 mM Na outside and 200 mM K inside, and 40 pS in 400 mM solutions. Reversal potentials in the 200 Na parallel 200 K solutions ranged from +51 to +94 mV in multichannel patches, corresponding to selectivity ratios PNa/PK from 8 to 43. Large differences in reversal potentials were seen even among patches from the same cell. Several controls rule out obvious sources of error in the reversal potential measurements. It is concluded that there is heterogeneity in the selectivity properties of the Na channels.

scholarly journals Spatiotemporal dynamics of auditory attention synchronize with speech

2016 ◽  
Vol 113 (14) ◽  
pp. 3873-3878 ◽  
Author(s):  
Malte Wöstmann ◽  
Björn Herrmann ◽  
Burkhard Maess ◽  
Jonas Obleser
Keyword(s):  
Spatial Attention ◽  
Time Course ◽  
Speech Rate ◽  
Temporal Structure ◽  
Low Frequency ◽  
Spatial Location ◽  
Brain Regions ◽  
Hemispheric Lateralization ◽  
Speech Comprehension ◽  
Alpha Power

Attention plays a fundamental role in selectively processing stimuli in our environment despite distraction. Spatial attention induces increasing and decreasing power of neural alpha oscillations (8–12 Hz) in brain regions ipsilateral and contralateral to the locus of attention, respectively. This study tested whether the hemispheric lateralization of alpha power codes not just the spatial location but also the temporal structure of the stimulus. Participants attended to spoken digits presented to one ear and ignored tightly synchronized distracting digits presented to the other ear. In the magnetoencephalogram, spatial attention induced lateralization of alpha power in parietal, but notably also in auditory cortical regions. This alpha power lateralization was not maintained steadily but fluctuated in synchrony with the speech rate and lagged the time course of low-frequency (1–5 Hz) sensory synchronization. Higher amplitude of alpha power modulation at the speech rate was predictive of a listener’s enhanced performance of stream-specific speech comprehension. Our findings demonstrate that alpha power lateralization is modulated in tune with the sensory input and acts as a spatiotemporal filter controlling the read-out of sensory content.

Autonomic responses during acute myocardial infarction in the rat model: implications for arrhythmogenesis

2018 ◽  
Vol 29 (4) ◽  
pp. 339-345 ◽  
Author(s):  
Theofilos M. Kolettis ◽  
Marianthi Kontonika ◽  
Panagiotis Lekkas ◽  
Antonios P. Vlahos ◽  
Giannis G. Baltogiannis ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Heart Rate ◽  
Sympathetic Activity ◽  
Time Course ◽  
Left Ventricular ◽  
Fluctuation Analysis ◽  
Vagal Activity ◽  
Ventricular Tachyarrhythmias ◽  
Autonomic Responses

AbstractBackgroundAutonomic responses participate in the pathophysiology of acute myocardial infarction, but their precise time course remains unclear. Here, we investigated the autonomic activity and ventricular tachyarrhythmias in conscious, unrestrained rats post-infarction.MethodsThe left coronary artery was ligated in 12 Wistar rats, and six rats were sham operated, followed by 24-h electrocardiographic recording via implanted telemetry transmitters. Sympathetic activity was assessed by detrended fluctuation analysis and vagal activity by time- and frequency-domain analysis of heart rate variability. The duration of the ventricular tachyarrhythmias was measured, and voluntary motion served as a marker of heart failure.ResultsIn sham-operated rats, heart rate and sympathetic activity remained low, whereas vagal activity rose progressively after the fourth hour. Post-ligation, medium-sized antero-septal necrosis was observed, reaching ~20% of the left ventricular volume; tachyarrhythmias were frequent, displaying a bimodal curve, and motion counts were low. Vagal activity decreased early post-ligation, coinciding with a high incidence of tachyarrhythmias, but tended to rise subsequently in rats with higher motion counts. Sympathetic activity increased after the third hour, along with a second tachyarrhythmia peak, and remained elevated throughout the 24-h period.ConclusionsVagal withdrawal, followed by gradual sympathetic activation, may participate in arrhythmogenesis during acute myocardial infarction.

scholarly journals Potassium conductance of the squid giant axon. Single-channel studies.

1988 ◽  
Vol 92 (2) ◽  
pp. 179-196 ◽  
Author(s):  
I Llano ◽  
C K Webb ◽  
F Bezanilla
Keyword(s):  
Time Course ◽  
Single Channel ◽  
Potassium Conductance ◽  
Giant Axon ◽  
Squid Giant Axon ◽  
K Channel ◽  
Delayed Rectifier ◽  
Fluctuation Analysis ◽  
Patch Clamp Technique ◽  
Relative Contribution

The patch-clamp technique was implemented in the cut-open squid giant axon and used to record single K channels. We present evidence for the existence of three distinct types of channel activities. In patches that contained three to eight channels, ensemble fluctuation analysis was performed to obtain an estimate of 17.4 pS for the single-channel conductance. Averaged currents obtained from these multichannel patches had a time course of activation similar to that of macroscopic K currents recorded from perfused squid giant axons. In patches where single events could be recorded, it was possible to find channels with conductances of 10, 20, and 40 pS. The channel most frequently encountered was the 20-pS channel; for a pulse to 50 mV, this channel had a probability of being open of 0.9. In other single-channel patches, a channel with a conductance of 40 pS was present. The activity of this channel varied from patch to patch. In some patches, it showed a very low probability of being open (0.16 for a pulse to 50 mV) and had a pronounced lag in its activation time course. In other patches, the 40-pS channel had a much higher probability of being open (0.75 at a holding potential of 50 mV). The 40-pS channel was found to be quite selective for K over Na. In some experiments, the cut-open axon was exposed to a solution containing no K for several minutes. A channel with a conductance of 10 pS was more frequently observed after this treatment. Our study shows that the macroscopic K conductance is a composite of several K channel types, but the relative contribution of each type is not yet clear. The time course of activation of the 20-pS channel and the ability to render it refractory to activation only by holding the membrane potential at a positive potential for several seconds makes it likely that it is the predominant channel contributing to the delayed rectifier conductance.

scholarly journals Voltage Gating of Shaker K+ Channels

1998 ◽  
Vol 112 (2) ◽  
pp. 223-242 ◽  
Author(s):  
Beatriz M. Rodríguez ◽  
Daniel Sigg ◽  
Francisco Bezanilla
Keyword(s):  
Temperature Dependence ◽  
Time Course ◽  
Recovery Period ◽  
Fluctuation Analysis ◽  
Kinetic Properties ◽  
Temperature Dependent ◽  
Open Probability ◽  
Voltage Range ◽  
K Channels ◽  
Gating Charge

Ionic (Ii) and gating currents (Ig) from noninactivating Shaker H4 K+ channels were recorded with the cut-open oocyte voltage clamp and macropatch techniques. Steady state and kinetic properties were studied in the temperature range 2–22°C. The time course of Ii elicited by large depolarizations consists of an initial delay followed by an exponential rise with two kinetic components. The main Ii component is highly temperature dependent (Q10 > 4) and mildly voltage dependent, having a valence times the fraction of electric field (z) of 0.2–0.3 eo. The Ig On response obtained between −60 and 20 mV consists of a rising phase followed by a decay with fast and slow kinetic components. The main Ig component of decay is highly temperature dependent (Q10 > 4) and has a z between 1.6 and 2.8 eo in the voltage range from −60 to −10 mV, and ∼0.45 eo at more depolarized potentials. After a pulse to 0 mV, a variable recovery period at −50 mV reactivates the gating charge with a high temperature dependence (Q10 > 4). In contrast, the reactivation occurring between −90 and −50 mV has a Q10 = 1.2. Fluctuation analysis of ionic currents reveals that the open probability decreases 20% between 18 and 8°C and the unitary conductance has a low temperature dependence with a Q10 of 1.44. Plots of conductance and gating charge displacement are displaced to the left along the voltage axis when the temperature is decreased. The temperature data suggests that activation consists of a series of early steps with low enthalpic and negative entropic changes, followed by at least one step with high enthalpic and positive entropic changes, leading to final transition to the open state, which has a negative entropic change.

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