Statistical test for peri-stimulus time histograms in assessing motor neuron activity

2002 ◽  
Vol 40 (4) ◽  
pp. 462-468 ◽  
Author(s):  
J. Ushiba ◽  
Y. Tomita ◽  
Y. Masakado ◽  
Y. Komune ◽  
Y. Muraoka
Keyword(s):  
Motor Neuron ◽  
Statistical Test ◽  
Neuron Activity ◽  
Stimulus Time

scholarly journals Loss of Correlated Motor Neuron Activity during Synaptic Competition at Developing Neuromuscular Synapses

Neuron ◽  
2001 ◽  
Vol 31 (3) ◽  
pp. 395-408 ◽  
Author(s):  
Kirkwood E. Personius ◽  
Rita J. Balice-Gordon
Keyword(s):  
Motor Neuron ◽  
Neuron Activity ◽  
Synaptic Competition ◽  
Neuromuscular Synapses

Aplysia ink release: central locus for selective sensitivity to long-duration stimuli

1979 ◽  
Vol 42 (5) ◽  
pp. 1223-1232 ◽  
Author(s):  
E. Shapiro ◽  
J. Koester ◽  
J. H. Byrne
Keyword(s):  
Motor Neuron ◽  
Spike Train ◽  
Motor Neurons ◽  
Neural Circuit ◽  
Reversal Potential ◽  
Secretory Process ◽  
Neuron Activity ◽  
Long Duration ◽  
Noxious Stimuli ◽  
Selective Sensitivity

1. A behavioral and electrophysiological analysis of defensive ink release in Aplysia californica was performed to examine the response of this behavior and its underlying neural circuit to various-duration noxious stimuli. 2. Three separate behavioral protocols were employed using electrical shocks to the head as noxious stimuli to elicit ink release. Ink release was found to be selectively responsive to longer duration stimuli, and to increase in a steeply graded fashion as duration is increased. 3. Intracellular stimulation of ink motor neurons revealed that ink release is a linear function of motor neuron spike train duration, indicating that the selective sensitivity of the behavior to long-duration stimuli is not due to a nonlinearity in the glandular secretory process. 4. In contrast, electrophysiological examination of ink motor neuron activity in response to sustained head shock revealed an accelerating spike train. During the later part of the spike train, compound excitatory synaptic potentials show a positive shift in reversal potential. 5. Our results suggest a central locus for the mechanisms that determine sensitivity of inking behavior to stimulus duration. 6. In contrast to ink release, defensive gill withdrawal was found to be extremely sensitive to short-duration stimuli.

Spinal Cord Coordination of Hindlimb Movements in the Turtle: Intralimb Temporal Relationships During Scratching and Swimming

1997 ◽  
Vol 78 (3) ◽  
pp. 1394-1403 ◽  
Author(s):  
Edelle C. Field ◽  
Paul S. G. Stein
Keyword(s):  
Spinal Cord ◽  
Motor Neuron ◽  
Activity Patterns ◽  
Angular Position ◽  
Knee Extension ◽  
Neuron Activity ◽  
Spinal Circuitry ◽  
Temporal Relationships ◽  
Kinematic Analyses ◽  
Behavioral Event

Field, Edelle C. and Paul S. G. Stein. Spinal cord coordination of hindlimb movements in the turtle: intralimb temporal relationships during scratching and swimming. J. Neurophysiol. 78: 1394–1403, 1997. Spinal cord neuronal circuits generate motor neuron activity patterns responsible for rhythmic hindlimb behaviors such as scratching and swimming. Kinematic analyses of limb movements generated by this motor neuron output reveal important characteristics of these behaviors. Intralimb kinematics of the turtle hindlimb were characterized during five distinct rhythmic forms of behavior: three forms of scratching and two forms of swimming. In each movement cycle for each form, the angles of the hip and knee joints were measured as well as the timing of a behavioral event, e.g., rub onset in scratching or powerstroke onset in swimming. There were distinct differences between the kinematics of different forms of the same behavior, e.g., rostral scratch versus pocket scratch. In contrast, there were striking similarities between forms of different behaviors, e.g., rostral scratch versus forward swimming. For each form of behavior there was a characteristic angular position of the hip at the onset of each behavioral event (rub or powerstroke). The phase of the onset of knee extension within the hip position cycle occurred while the hip was flexing in the rostral scratch and forward swim and while the hip was extending in the pocket scratch, caudal scratch, and back-paddling form of swimming. The phase of the onset of the behavioral event was not statistically different between rostral scratch and forward swim; nor was it different between pocket scratch and caudal scratch. These observations of similarities at the movement level support the suggestion that further similarities, such as shared spinal circuitry, may be present at the neural circuitry level as well.

scholarly journals Activity-Driven Synaptic and Axonal Degeneration in Canine Motor Neuron Disease

2004 ◽  
Vol 92 (2) ◽  
pp. 1175-1181 ◽  
Author(s):  
Dario I. Carrasco ◽  
Mark M. Rich ◽  
Qingbo Wang ◽  
Timothy C. Cope ◽  
Martin J. Pinter
Keyword(s):  
Motor Neuron ◽  
Motor Neuron Disease ◽  
Motor Unit ◽  
Neuromuscular Junctions ◽  
Muscular Atrophy ◽  
Motor Axon ◽  
Medial Gastrocnemius ◽  
Neuron Activity ◽  
Functional Changes ◽  
Unit Function

The role of neuronal activity in the pathogenesis of neurodegenerative disease is largely unknown. In this study, we examined the effects of increasing motor neuron activity on the pathogenesis of a canine version of inherited motor neuron disease (hereditary canine spinal muscular atrophy). Activity of motor neurons innervating the ankle extensor muscle medial gastrocnemius (MG) was increased by denervating close synergist muscles. In affected animals, 4 wk of synergist denervation accelerated loss of motor-unit function relative to control muscles and decreased motor axon conduction velocities. Slowing of axon conduction was greatest in the most distal portions of motor axons. Morphological analysis of neuromuscular junctions (NMJs) showed that these functional changes were associated with increased loss of intact innervation and with the appearance of significant motor axon and motor terminal sprouting. These effects were not observed in the MG muscles of age-matched, normal animals with synergist denervation for 5 wk. The results indicate that motor neuron action potential activity is a major contributing factor to the loss of motor-unit function and degeneration in inherited canine motor neuron disease.

Slow Temporal Filtering May Largely Explain the Transformation of Stick Insect (Carausius morosus) Extensor Motor Neuron Activity Into Muscle Movement

2007 ◽  
Vol 98 (3) ◽  
pp. 1718-1732 ◽  
Author(s):  
Scott L. Hooper ◽  
Christoph Guschlbauer ◽  
Géraldine von Uckermann ◽  
Ansgar Büschges
Keyword(s):  
Motor Neuron ◽  
Time Constant ◽  
Time Scale ◽  
Stick Insect ◽  
Neuron Activity ◽  
Temporal Filtering ◽  
Time Constants ◽  
Neural Input ◽  
Spike Number ◽  
Contraction And Relaxation

Understanding how nervous systems generate behavior requires understanding how muscles transform neural input into movement. The stick insect extensor tibiae muscle is an excellent system in which to study this issue because extensor motor neuron activity is highly variable during single leg walking and extensor muscles driven with this activity produce highly variable movements. We showed earlier that spike number, not frequency, codes for extensor amplitude during contraction rises, which implies the muscle acts as a slow filter on the time scale of burst interspike intervals (5–10 ms). We examine here muscle response to spiking variation over entire bursts, a time scale of hundreds of milliseconds, and directly measure muscle time constants. Muscle time constants differ during contraction and relaxation, and contraction time constants, although variable, are always extremely slow (200–700 ms). Models using these data show that extremely slow temporal filtering alone can explain much of the observed transform properties. This work also revealed an unexpected (to us) ability of slow filtering to transform steadily declining inputs into constant amplitude outputs. Examination of the effects of time constant variability on model output showed that variation within an SD primarily altered output amplitude, but variation across the entire range also altered contraction shape. These substantial changes suggest that understanding the basis of this variation is central to predicting extensor activity and that the animal could theoretically vary muscle time constant to match extensor response to changing behavioral need.

scholarly journals TRPM8-mediated cutaneous stimulation modulates motor neuron activity during treadmill stepping in mice

2019 ◽  
Vol 69 (6) ◽  
pp. 931-938 ◽  
Author(s):  
Kotaro Tamura ◽  
Satoshi Sugita ◽  
Tadayuki Tokunaga ◽  
Yoshihiko Minegishi ◽  
Noriyasu Ota
Keyword(s):  
Motor Neuron ◽  
Neuron Activity ◽  
Cutaneous Stimulation ◽  
Treadmill Stepping

Different Motor Neuron Spike Patterns Produce Contractions With Very Similar Rises in Graded Slow Muscles

2007 ◽  
Vol 97 (2) ◽  
pp. 1428-1444 ◽  
Author(s):  
Scott L. Hooper ◽  
Christoph Guschlbauer ◽  
Géraldine von Uckermann ◽  
Ansgar Büschges
Keyword(s):  
Motor Neuron ◽  
Motor Nerve ◽  
Stick Insect ◽  
Spike Frequency ◽  
Neuron Activity ◽  
Number Range ◽  
Neuron Spike ◽  
Extensor Muscles ◽  
Spike Number ◽  
Spike Patterns

Graded muscles produce small twitches in response to individual motor neuron spikes. During the early part of their contractions, contraction amplitude in many such muscles depends primarily on the number of spikes the muscle has received, not the frequency or pattern with which they were delivered. Stick insect ( Carausius morosus) extensor muscles are graded and thus would likely show spike-number dependency early in their contractions. Tonic stimulations of the extensor motor nerve showed that the response of the muscles differed from the simplest form of spike-number dependency. However, these differences actually increased the spike-number range over which spike-number dependency was present. When the motor nerve was stimulated with patterns mimicking the motor neuron activity present during walking, amplitude during contraction rises also depended much more on spike number than on spike frequency. A consequence of spike-number dependency is that brief changes in spike frequency do not alter contraction slope and we show here that extensor motor neuron bursts with different spike patterns give rise to contractions with very similar contraction rises. We also examined in detail the early portions of a large number of extensor motor neuron bursts recorded during single-leg walking and show that these portions of the bursts do not appear to have any common spike pattern. Although alternative explanations are possible, the simplest interpretation of these data is that extensor motor neuron firing during leg swing is not tightly controlled.

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