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
Decoding the organization of spinal circuits that control locomotion.
TL;DR: The emergent themes from this research are that the locomotor networks have a modular organization with distinct transmitter and molecular codes and that their organization is reconfigured with changes to the speed of locomotion or changes in gait.
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Current Principles of Motor Control, with Special Reference to Vertebrate Locomotion
TL;DR: This work aims at covering all main aspects of this complex behavior - from the operation of the microcircuits in the spinal cord to the systems and behavioral levels and extend from mammalian locomotion to the basic undulatory movements of lamprey and fish.
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Locomotor Rhythm Generation Linked to the Output of Spinal Shox2 Excitatory Interneurons
Kimberly J. Dougherty,Laskaro Zagoraiou,Laskaro Zagoraiou,Daisuke Satoh,Daisuke Satoh,Ismini Rozani,Staceyann Doobar,Silvia Arber,Silvia Arber,Thomas M. Jessell,Ole Kiehn +10 more
TL;DR: This work identifies an ipsilaterally projecting excitatory interneuron population, marked by the expression of Shox2 that overlaps partially with V2a interneurons, that appears to participate in the rhythm-generating kernel for spinal locomotion.
Journal ArticleDOI
Descending Command Neurons in the Brainstem that Halt Locomotion
Julien Bouvier,Julien Bouvier,Vittorio Caggiano,Roberto Leiras,Vanessa Caldeira,Carmelo Bellardita,Kira Balueva,Andrea Fuchs,Ole Kiehn +8 more
TL;DR: The V2a "stop neurons" represent a glutamatergic descending pathway that favors immobility and may thus help control the episodic nature of locomotion.
Journal ArticleDOI
V1 and V2b Interneurons Secure the Alternating Flexor-Extensor Motor Activity Mice Require for Limbed Locomotion
Jingming Zhang,Guillermo M. Lanuza,Guillermo M. Lanuza,Olivier Britz,Zhi Wang,Valerie C. Siembab,Ying Zhang,Tomoko Velasquez,Francisco J. Alvarez,Francisco J. Alvarez,Eric Frank,Martyn Goulding +11 more
TL;DR: This work shows that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally located inhibitory neurons, V1 and V2b interneurons (INs).
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