The Ancient Origins of Neural Substrates for Land Walking
MetadataShow full item record
© 2018 Elsevier Inc. Walking is the predominant locomotor behavior expressed by land-dwelling vertebrates, but it is unknown when the neural circuits that are essential for limb control first appeared. Certain fish species display walking-like behaviors, raising the possibility that the underlying circuitry originated in primitive marine vertebrates. We show that the neural substrates of bipedalism are present in the little skate Leucoraja erinacea, whose common ancestor with tetrapods existed ~420 million years ago. Leucoraja exhibits core features of tetrapod locomotor gaits, including left-right alternation and reciprocal extension-flexion of the pelvic fins. Leucoraja also deploys a remarkably conserved Hox transcription factor-dependent program that is essential for selective innervation of fin/limb muscle. This network encodes peripheral connectivity modules that are distinct from those used in axial muscle-based swimming and has apparently been diminished in most modern fish. These findings indicate that the circuits that are essential for walking evolved through adaptation of a genetic regulatory network shared by all vertebrates with paired appendages. Video Abstract: The circuits involved in limb control were established in the common ancestor to all vertebrates with pair appendages millions of years before the first tetrapod walked on land.
Showing items related by title, author, creator and subject.
Subregional DXA-derived vertebral bone mineral measures are stronger predictors of failure load in specimens with lower areal bone mineral density, compared to those with higher areal bone mineral densityBriggs, Andrew; Perilli, E.; Codrington, J.; Reynolds, K.; Parkinson, I.; Wark, J. (2014)Measurement of areal bone mineral density (aBMD) in intravertebral subregions may increase the diagnostic sensitivity of dual-energy X-ray absorptiometry (DXA)-derived parameters for vertebral fragility. This study ...
Repeat attenders at National Health Service walk-in centres - a descriptive study using routine dataMaheswaran, R.; Pearson, T.; Jiwa, Moyez (2009)Objectives Whilst numerous studies have examined repeat attendance at general practices or emergency departments, little is known about repeat attenders at walk-in centres. The aim of this study was to examine age, gender, ...
Coenen, Pieter; Van Werven, G.; Van Nunen, M.; Van Dieën, J.; Gerrits, K.; Janssen, T. (2012)Objective: There is increasing evidence that robot-assisted treadmill training might be useful for gait rehabilitation after stroke. The aim of this study was to evaluate the muscle activity of stroke patients during ...