Journal ArticleDOI
Dual-mode operation of neuronal networks involved in left-right alternation
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TLDR
It is shown that ablation of a group of transcriptionally defined commissural neurons—the V0 population—leads to a quadrupedal hopping at all frequencies of locomotion, with two subgroups of V0 neurons required for the existence of left–right alternating modes at different speeds of locomotions.Abstract:
All forms of locomotion are repetitive motor activities that require coordinated bilateral activation of muscles. The executive elements of locomotor control are networks of spinal neurons that determine gait pattern through the sequential activation of motor-neuron pools on either side of the body axis. However, little is known about the constraints that link left-right coordination to locomotor speed. Recent advances have indicated that both excitatory and inhibitory commissural neurons may be involved in left-right coordination. But the neural underpinnings of this, and a possible causal link between these different groups of commissural neurons and left-right alternation, are lacking. Here we show, using intersectional mouse genetics, that ablation of a group of transcriptionally defined commissural neurons--the V0 population--leads to a quadrupedal hopping at all frequencies of locomotion. The selective ablation of inhibitory V0 neurons leads to a lack of left-right pattern at low frequencies, mixed coordination at medium frequencies, and alternation at high locomotor frequencies. When ablation is targeted to excitatory V0 neurons, left-right alternation is present at low frequencies, and hopping is restricted to medium and high locomotor frequencies. Therefore, the intrinsic logic of the central control of locomotion incorporates a modular organization, with two subgroups of V0 neurons required for the existence of left-right alternating modes at different speeds of locomotion. The two molecularly distinct sets of commissural neurons may constrain species-related naturally occurring frequency-dependent coordination and be involved in the evolution of different gaits.read more
Citations
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Journal ArticleDOI
Pace of movement: the role of single neurons in the subthalamic nucleus
TL;DR: These findings suggest that disparate schemes are utilized in the STN for neuronal recruitment for motor control of the upper and lower extremities and indicate a distributed model of motor control within the STn.
Journal ArticleDOI
Left–Right Locomotor Coordination in Human Neonates
TL;DR: In this paper , 46 neonates performed bilateral and unilateral stepping with one leg blocked in different positions, and they found that the hip position of the blocked limb significantly affected ipsilateral but not contralateral, muscle activities.
Book ChapterDOI
Recruitment of Motoneurons.
Vatsala Thirumalai,Urvashi Jha +1 more
TL;DR: The recruitment patterns of motoneurons are discussed in light of new and exciting studies that show modular sub networks of interneurons and their post-synaptic mot oneurons have been shown to drive movements with varying intensities.
Dissertation
Generation and selection of motor behaviors neural circuits and endocannabinoid modulation
TL;DR: This thesis shows that the release of endocannabinoids increases the excitability of the spinal locomotor network by depressing inhibitory synaptic transmission and potentiating excitatory synaptic transmission, and shows the existence of electrical coupling between motoneurons andexcitatory V2a interneurons, which extends mot oneurons influence onto premotor V2 a interneuronons.
Posted ContentDOI
Silencing long-descending inter-enlargement propriospinal neurons improves hindlimb stepping after contusive spinal cord injuries
Courtney T Shepard,Brandon L Brown,Morgan A. Van Rijswijck,Rachel M. Zalla,Darlene A. Burke,Johnny R. Morehouse,Amberley S Riegler,Scott R. Whittemore,David S.K. Magnuson +8 more
TL;DR: Conditional silencing of the long ascending propriospinal neurons in the intact adult rat resulted in disrupted alternation of each limb pair and after a thoracic contusion SCI significantly improved locomotor function, leading to speculate that the LAPNs and LDPNs have similar roles in the exchange of temporal information between the cervical and lumbar rhythm generating centers.
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Journal ArticleDOI
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