Sensation-Targeted Motor Control: Every Spike Counts? Focus on: “Whisker Movements Evoked by Stimulation of Single Motor Neurons in the Facial Nucleus of the Rat”

2008 ◽  
Vol 99 (6) ◽  
pp. 2757-2759 ◽  
Author(s):  
Erez Simony ◽  
Inbar Saraf-Sinik ◽  
David Golomb ◽  
Ehud Ahissar
Keyword(s):  
Motor Control ◽  
Motor Neurons ◽  
Facial Nucleus ◽  
Single Motor ◽  
Stimulation Of

Whisker Movements Evoked by Stimulation of Single Motor Neurons in the Facial Nucleus of the Rat

2008 ◽  
Vol 99 (6) ◽  
pp. 2821-2832 ◽  
Author(s):  
Lucas J. Herfst ◽  
Michael Brecht
Keyword(s):  
Motor Neurons ◽  
Large Range ◽  
Facial Nucleus ◽  
Time To Peak ◽  
Coding Scheme ◽  
Movement Characteristics ◽  
Output Structure ◽  
Single Spike ◽  
Stereotyped Movement ◽  
Stimulation Of

The lateral facial nucleus is the sole output structure whose neuronal activity leads to whisker movements. To understand how single facial nucleus neurons contribute to whisker movement we combined single-cell stimulation and high-precision whisker tracking. Half of the 44 stimulated neurons gave rise to fast whisker protraction or retraction movement, whereas no stimulation-evoked movements could be detected for the remainder. Direction, speed, and amplitude of evoked movements varied across neurons. Protraction movements were more common than retraction movements ( n = 16 vs. n = 4), had larger amplitudes (1.8 vs. 0.3° for single spike events), and most protraction movements involved only a single whisker, whereas most retraction movements involved multiple whiskers. We found a large range in the amplitude of single spike-evoked whisker movements (0.06–5.6°). Onset of the movement occurred at 7.6 (SD 2.5) ms after the spike and the time to peak deflection was 18.2 (SD 4.3) ms. Each spike reliably evoked a stereotyped movement. In two of five cases peak whisker deflection resulting from consecutive spikes was larger than expected when based on linear summation of single spike-evoked movement profiles. Our data suggest the following coding scheme for whisker movements in the facial nucleus. 1) Evoked movement characteristics depend on the identity of the stimulated neuron (a labeled line code). 2) The facial nucleus neurons are heterogeneous with respect to the movement properties they encode. 3) Facial nucleus spikes are translated in a one-to-one manner into whisker movements.

Synaptic regulation of cellular properties and burst oscillations of neurons in gastric mill system of spiny lobsters, Panulirus interruptus

1984 ◽  
Vol 52 (1) ◽  
pp. 54-73 ◽  
Author(s):  
D. F. Russell ◽  
D. K. Hartline
Keyword(s):  
Motor Neurons ◽  
Pattern Generator ◽  
Stomatogastric Ganglion ◽  
Gastric Mill ◽  
Panulirus Interruptus ◽  
Synaptic Regulation ◽  
Gastric Cells ◽  
Current Pulses ◽  
Regenerative Property ◽  
Stimulation Of

The properties of neurons in the stomatogastric ganglion (STG) participating in the pattern generator for the gastric mill rhythm were studied by intracellular current injection under several conditions: during ongoing gastric rhythms, in the nonrhythmic isolated STG, after stimulation of the nerve carrying central nervous system (CNS) inputs to the STG, or under Ba2+ or Sr2+. Slow regenerative depolarizations during ongoing rhythms were demonstrated in the anterior median, cardiopyloric, lateral cardiac, gastropyloric, and continuous inhibitor (AM, CP, LC, GP, and CI) neurons according to criteria such as voltage dependency, burst triggering, and termination by brief current pulses, etc. Experiments showed that regenerative-like behavior was not due to synaptic network interactions. The slow regenerative responses were abolished by isolating the stomatogastric ganglion but could be reestablished by stimulating the input nerve. This indicates that certain CNS inputs synaptically induce the regenerative property in specific gastric neurons. Slow regenerative depolarizations were not demonstrable in gastric mill (GM) motor neurons. Their burst oscillations and firing rate were instead proportional to injected current. CNS inputs evoked a prolonged depolarization in GM motor neurons, apparently by a nonregenerative mechanism. All the gastric cells showed prolonged regenerative potentials under 0.5-1.5 mM Ba2+. We conclude that the gastric neurons of the STG can be divided into three types according to their properties: those with a regenerative capability, a repetitively firing type, and a nonregenerative "proportional" type. The cells are strongly influenced by several types of CNS inputs, including "gastric command fibers."

Connections between thoraco-coxal proprioceptive afferents and motor neurons in the locust

2000 ◽  
Vol 203 (3) ◽  
pp. 435-445
Author(s):  
M. Wildman
Keyword(s):  
Electrical Stimulation ◽  
Sensory Neurons ◽  
Motor Neurons ◽  
Chordotonal Organ ◽  
Synaptic Connections ◽  
Afferent Neurons ◽  
Postsynaptic Potentials ◽  
The Common ◽  
Proprioceptive Afferents ◽  
Stimulation Of

The position of the coxal segment of the locust hind leg relative to the thorax is monitored by a variety of proprioceptors, including three chordotonal organs and a myochordotonal organ. The sensory neurons of two of these proprioceptors, the posterior joint chordotonal organ (pjCO) and the myochordotonal organ (MCO), have axons in the purely sensory metathoracic nerve 2C (N2C). The connections made by these afferents with metathoracic motor neurons innervating thoraco-coxal and wing muscles were investigated by electrical stimulation of N2C and by matching postsynaptic potentials in motor neurons with afferent spikes in N2C. Stretch applied to the anterior rotator muscle of the coxa (M121), with which the MCO is associated, evoked sensory spikes in N2C. Some of the MCO afferent neurons make direct excitatory chemical synaptic connections with motor neurons innervating the thoraco-coxal muscles M121, M126 and M125. Parallel polysynaptic pathways via unidentified interneurons also exist between MCO afferents and these motor neurons. Connections with the common inhibitor 1 neuron and motor neurons innervating the thoraco-coxal muscles M123/4 and wing muscles M113 and M127 are polysynaptic. Afferents of the pjCO also make polysynaptic connections with motor neurons innervating thoraco-coxal and wing muscles, but no evidence for monosynaptic pathways was found.

The Function of a Heteromorph Antennule in a Spiny Lobster, Panulirus Argus

1965 ◽  
Vol 43 (1) ◽  
pp. 55-78
Author(s):  
D. M. MAYNARD ◽  
M. J. COHEN
Keyword(s):  
Motor Neurons ◽  
Spiny Lobster ◽  
Panulirus Argus ◽  
Intracellular Recordings ◽  
Afferent Fibre ◽  
The Third ◽  
Naturally Occurring ◽  
Withdrawal Response ◽  
Basic Similarity ◽  
Stimulation Of

1. The effects of electrical and mechanical stimulation upon a ‘naturally occurring’ heteromorph appendage growing in place of one eyestalk in Panulirus argus were examined. The heteromorph resembled the outer flagellum of the antennule in form. 2. Heteromorph stimulation elicited both a generalized withdrawal response, and a specific depression of the third segment and flagellum of the ipsilateral antennule. Such a depression response was also elicited upon stimulation of the ipsilateral outer flagellum of the normal antennule and by no other input investigated. 3. The basic similarity of the two responses was confirmed by electromyography and by intracellular recordings from motor neurons and interneurons within the lobster brain. 4. It was concluded that at least one afferent fibre component from the heteromorph and normal flagellum terminated upon the same interneuron pools, while avoiding others, and that consequently these observations provide evidence for the formation of functional inter-neuronal connexions according to type specificity.

scholarly journals Nervous Control of Movement in Annelids

1960 ◽  
Vol 37 (1) ◽  
pp. 46-56
Author(s):  
DONALD MELVIN WILSON
Keyword(s):  
Motor Neurons ◽  
Fast Response ◽  
Slow Response ◽  
Nervous Control ◽  
Chemical Stimuli ◽  
Nerve Muscle ◽  
Slow System ◽  
Fast Responses ◽  
Stimulation Of

1. Nerve muscle preparations of the segmental nerves and associated muscles have been made using a nereid polychaete, Neanthes brandti (Malmgren). 2. Two kinds of response, differing in threshold and latency, were found. The ‘fast’ response is large at the first shock and (at frequencies above 1/sec.) decreases thereafter. The ‘slow’ response is small but facilitates with repetition at frequencies above 10/sec. Facilitation reaches a maximum after 3 or 4 shocks. 3. Isolated parapodia show several distinct reflex movements to mechanical and chemical stimuli. These must involve motor neurons in the parapodial ganglion. 4. Stimulation of the segmental nerves of the leech, Hirudo, evokes facilitating muscle potentials resembling in most details those of the ‘slow‘ system in Neanthes. 5. The ‘fast’ and ‘slow’ responses are discussed in comparison with other invertebrate systems, especially those of arthropods. The ‘slow’ responses in annelids show less facilitation. The ‘fast’ responses of polychaetes fatigue quickly and are probably useful only in ‘startle’ responses.

scholarly journals An Atoh1 CRE Knock-In Mouse Labels Motor Neurons Involved in Fine Motor Control

eNeuro ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. ENEURO.0221-20.2021
Author(s):  
Osita W. Ogujiofor ◽  
Iliodora V. Pop ◽  
Felipe Espinosa ◽  
Razaq O. Durodoye ◽  
Michael L. Viacheslavov ◽  
...  
Keyword(s):  
Motor Control ◽  
Motor Neurons ◽  
Fine Motor ◽  
Fine Motor Control

Reflex responses in active muscles elicited by stimulation of low-threshold afferents from the human foot

1992 ◽  
Vol 67 (5) ◽  
pp. 1375-1384 ◽  
Author(s):  
A. M. Aniss ◽  
S. C. Gandevia ◽  
D. Burke
Keyword(s):  
Motor Units ◽  
Medial Gastrocnemius ◽  
Emg Activity ◽  
Onset Latency ◽  
Single Motor ◽  
Reflex Responses ◽  
Posterior Tibial ◽  
Single Motor Units ◽  
Low Threshold ◽  
Stimulation Of

1. Reflex responses were elicited in muscles that act at the ankle by electrical stimulation of low-threshold afferents from the foot in human subjects who were reclining supine. During steady voluntary contractions, stimulus trains (5 pulses at 300 Hz) were delivered at two intensities to the sural nerve (1.2-4.0 times sensory threshold) or to the posterior tibial nerve (1.1-3.0 times motor threshold for the intrinsic muscles of the foot). Electromyographic (EMG) recordings were made from tibialis anterior (TA), peroneus longus (PL), soleus (SOL), medial gastrocnemius (MG), and lateral gastrocnemius (LG) muscles by the use of intramuscular wire electrodes. 2. As assessed by averages of rectified EMG, stimulation of the sural or posterior tibial nerves at nonpainful levels evoked a complex oscillation with onset latencies as early as 40 ms and lasting up to 200 ms in each muscle. The most common initial responses in TA were a decrease in EMG activity at an onset latency of 54 ms for sural stimuli, and an increase at an onset latency of 49 ms for posterior tibial stimuli. The response of PL to stimulation of the two nerves began with a strong facilitation of 44 ms (sural) and 49 ms (posterior tibial). With SOL, stimulation of both nerves produced early inhibition beginning at 45 and 50 ms, respectively. With both LG and MG, sural stimuli produced an early facilitation at 52-53 ms. However, posterior tibial stimuli produced different initial responses in these two muscles: facilitation in LG at 50 ms and inhibition in MG at 51 ms. 3. Perstimulus time histograms of the discharge of 61 single motor units revealed generally similar reflex responses as in multiunit EMG. However, different reflex components were not equally apparent in the responses of different single motor units: an individual motor unit could respond slightly differently with a change in stimulus intensity or background contraction level. The multiunit EMG record represents a global average that does not necessarily depict the precise pattern of all motor units contributing to the average. 4. When subjects stood erect without support and with eyes closed, reflex patterns were seen only in active muscles, and the patterns were similar to those in the reclining posture. 5. It is concluded that afferents from mechanoreceptors in the sole of the foot have multisynaptic reflex connections with the motoneuron pools innervating the muscles that act at the ankle. When the muscles are active in standing or walking, cutaneous feedback may play a role in modulating motoneuron output and thereby contribute to stabilization of stance and gait.

The Pedal Neurons of Aplysia Punctata

1968 ◽  
Vol 48 (1) ◽  
pp. 127-140
Author(s):  
D. A. DORSETT
Keyword(s):  
Motor Neurons ◽  
The Other ◽  
Afferent Pathways ◽  
Stimulation Of

1. Three classes of neurons have been identified in the pedal ganglia of Aplysia punctata. 2. The motor neurons, which may be unipolar or bipolar, have the axon passing into one of the pedal nerves and in the case of the bipolars, the other branch entering the pedal commissure. This synapses with neurons on the opposite side, thus providing an integrative link between the ganglia. 3. The interneurons are without axons in the pedal nerves or commissure, although afferent pathways to these cells and the motor neurons occur in the pedal nerves in a variety of combinations. 4. The pathways in the ipsilateral nerves are for the most part excitatory, but inhibitory fibres occur in the posterior pedal nerve. 5. Inhibitory potentials were often obtained in the interneurons by stimulation of the pedal commissure. 6. A second type of coordinative pathway is provided by fibres which enter the CNS in one of the pedal nerves and terminate on neurons in both pedal ganglia.

The Activity of Single Motor Fibres in Arthropods I. The Dragonfly Nymph

1965 ◽  
Vol 42 (3) ◽  
pp. 447-461
Author(s):  
ANN KNIGHTS
Keyword(s):  
Electrical Stimulation ◽  
Temporal Summation ◽  
Reciprocal Relationship ◽  
Response Patterns ◽  
Insect Muscle ◽  
Frequency Sensitivity ◽  
Single Motor ◽  
Dragonfly Nymph ◽  
Central Inhibition ◽  
Stimulation Of

1. Responses to mechanical and electrical stimulation have been investigated in single motor fibres dissected in the segmental nerves of the dragonfly nymph. 2. A large proportion of fibres possessed a background discharge which was often accelerated of inhibited on stimulation. Examples of central inhibition were common. 3. Efferent responses varied in type, delay and regularity, both with the input under stimulation and with the frequency and intensity of the volley. The majority of fibres responded to stimulation of more than one nerve root. 4. In many motor fibres changes in the parameters of stimulation demonstrated a reciprocal relationship between and frequency. An enhanced responsiveness occurred with frequency increases in the range of 10-100/sec. indicatind a considerable importance of temporal summation/facilitation. 5. The characteristic frequency-sensitivity of motor fibres and the variability of their response patterns are discussed in relation to the control of insect muscle.

scholarly journals Diabetes Mellitus-Related Dysfunction of the Motor System

2020 ◽  
Vol 21 (20) ◽  
pp. 7485
Author(s):  
Ken Muramatsu
Keyword(s):  
Motor Control ◽  
Motor Neurons ◽  
Motor System ◽  
Corticospinal Tract ◽  
Experimental Studies ◽  
Sensory System ◽  
Treatment Strategies ◽  
Motor Deficits ◽  
New Perspective ◽  
The Brain

Although motor deficits in humans with diabetic neuropathy have been extensively researched, its effect on the motor system is thought to be lesser than that on the sensory system. Therefore, motor deficits are considered to be only due to sensory and muscle impairment. However, recent clinical and experimental studies have revealed that the brain and spinal cord, which are involved in the motor control of voluntary movement, are also affected by diabetes. This review focuses on the most important systems for voluntary motor control, mainly the cortico-muscular pathways, such as corticospinal tract and spinal motor neuron abnormalities. Specifically, axonal damage characterized by the proximodistal phenotype occurs in the corticospinal tract and motor neurons with long axons, and the transmission of motor commands from the brain to the muscles is impaired. These findings provide a new perspective to explain motor deficits in humans with diabetes. Finally, pharmacological and non-pharmacological treatment strategies for these disorders are presented.

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