scholarly journals Developmental constraints of quadrupedal coordination across crawling styles in human infants

2012 ◽  
Vol 107 (11) ◽  
pp. 3050-3061 ◽  
Author(s):  
Susan K. Patrick ◽  
J. Adam Noah ◽  
Jaynie F. Yang
Keyword(s):  
Nervous System ◽  
Stance Phase ◽  
Swing Phase ◽  
Interlimb Coordination ◽  
Young Age ◽  
Developmental Constraints ◽  
Human Infants ◽  
Coordination Patterns ◽  
Duration Of Cycle ◽  
Developing Nervous System

Human infants can crawl using several very different styles; this diversity appears at first glance to contradict our previous findings from hands-and-knees crawling, which suggested that there were strict limitations on coordination, imposed either mechanically or by the developing nervous system. To determine whether coordination was similarly restricted across crawling styles, we studied free crawling overground in 22 infants who used a number of different locomotor strategies. Despite the wide variety in the use of individual limbs and even the number of limbs used, the duration of the stance phase increased with duration of cycle, whereas the duration of the swing phase remained more constant. Additionally, all infants showed organized, rhythmic interlimb coordination. Alternating patterns (e.g., trotlike) predominated (86% of infants). Alternatively, yet much less frequently, all limbs used could work in synchrony (14% of infants). Pacelike patterns were never observed, even in infants that crawled with the belly remaining in contact with the ground so that stability was not a factor. To explore the robustness of the interlimb coordination, a perturbation that prolonged swing of the leg was imposed on 14 additional infants crawling on hands and knees overground or on the treadmill. The perturbation led to a resetting of the crawling pattern, but never to a change in the coordination of the limbs. The findings concur with those regarding other infant animals, together suggesting that the nervous system itself limits the coordination patterns available at a young age.

scholarly journals Interlimb Coordination in Human Crawling Reveals Similarities in Development and Neural Control With Quadrupeds

2009 ◽  
Vol 101 (2) ◽  
pp. 603-613 ◽  
Author(s):  
Susan K. Patrick ◽  
J. Adam Noah ◽  
Jaynie F. Yang
Keyword(s):  
Neural Control ◽  
Force Plate ◽  
Interlimb Coordination ◽  
Limb Length ◽  
Bipedal Walking ◽  
Human Infants ◽  
Hind Limbs ◽  
Underlying Mechanisms ◽  
Hands And Feet ◽  
Coordination Patterns

The study of quadrupeds has furnished most of our understanding of mammalian locomotion. To allow a more direct comparison of coordination between the four limbs in humans and quadrupeds, we studied crawling in the human, a behavior that is part of normal human development and mechanically more similar to quadrupedal locomotion than is bipedal walking. Interlimb coordination during hands-and-knees crawling is compared between humans and quadrupeds and between human infants and adults. Mechanical factors were manipulated during crawling to understand the relative contributions of mechanics and neural control. Twenty-six infants and seven adults were studied. Video, force plate, and electrogoniometer data were collected. Belt speed of the treadmill, width of base, and limb length were manipulated in adults. Influences of unweighting and limb length were explored in infants. Infants tended to move diagonal limbs together (trot-like). Adults additionally moved ipsilateral limbs together (pace-like). At lower speeds, movements of the four limbs were more equally spaced in time, with no clear pairing of limbs. At higher speeds, running symmetrical gaits were never observed, although one adult galloped. Widening stance prevented adults from using the pace-like gait, whereas lengthening the hind limbs (hands-and-feet crawling) largely prevented the trot-like gait. Limb length and unweighting had no effect on coordination in infants. We conclude that human crawling shares features both with other primates and with nonprimate quadrupeds, suggesting similar underlying mechanisms. The greater restriction in coordination patterns used by infants suggests their nervous system has less flexibility.

Infants Adapt Their Stepping to Repeated Trip-Inducing Stimuli

2003 ◽  
Vol 90 (4) ◽  
pp. 2731-2740 ◽  
Author(s):  
Marco Y. C. Pang ◽  
Tania Lam ◽  
Jaynie F. Yang
Keyword(s):  
Nervous System ◽  
Knee Flexion ◽  
Swing Phase ◽  
Flexor Muscle ◽  
Human Infants ◽  
Knee Flexor ◽  
Muscle Torque ◽  
Stepping Pattern ◽  
One Step ◽  
Treadmill Belt

This study examined whether human infants under the age of 12 mo learn to modify their stepping pattern after repeated trip-inducing stimuli. Thirty three infants aged from 5 to 11 mo were studied. The infants were held over a moving treadmill belt to induce stepping. Occasionally, a mechanical tap was applied to the dorsum of the left foot during the early swing phase to elicit a high step. In some trials, the stimulus was applied for only one step. In other trials, the foot was stimulated for a few consecutive steps. We determined whether the infants continued to show high stepping immediately after the removal of the stimuli. The results showed that after the foot was touched for two or more consecutive steps, some infants continued to demonstrate high stepping for a few steps after the removal of the stimuli (i.e., aftereffect). Such adaptation was achieved by an increase in hip and knee flexor muscle torque, which led to greater hip and knee flexion during the early swing phase. Aftereffects were more commonly seen in older infants (9 mo or older). The results indicated that before the onset of independent walking, the locomotor circuitry in human infants is capable of adaptive locomotor plasticity. The increased incidence of aftereffect in older infants also suggests that the ability to adapt to repeated trip-inducing stimuli may be related to other factors such as experience in stepping and maturation of the nervous system.

Migratory Neural Crest Cells Phagocytose Cellular Debris in the Developing Nervous System

2019 ◽  
Author(s):  
Yunlu Zhu ◽  
Samantha C. Crowley ◽  
Andrew J. Latimer ◽  
Gwendolyn M. Lewis ◽  
Rebecca Nash ◽  
...  
Keyword(s):  
Nervous System ◽  
Neural Crest ◽  
Neural Crest Cells ◽  
Cellular Debris ◽  
Developing Nervous System

scholarly journals Immunohistochemical localization of phosphoenolpyruvate carboxykinase in adult and developing mouse tissues.

1990 ◽  
Vol 38 (2) ◽  
pp. 171-178 ◽  
Author(s):  
D B Zimmer ◽  
M A Magnuson
Keyword(s):  
Nervous System ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Submaxillary Gland ◽  
Cell Types ◽  
Immunohistochemical Localization ◽  
Mouse Tissues ◽  
Multiple Cell ◽  
Cell Type Specific ◽  
Immunohistochemical Techniques ◽  
Developing Nervous System

We used immunohistochemical techniques to analyze the cell distribution of phosphoenolpyruvate carboxykinase (PEPCK) in adult and developing mouse tissues. PEPCK immunoreactivity was detected in many tissues, including some that had not been previously reported to contain PEPCK enzyme activity (bladder, stomach, ovary, vagina, parotid gland, submaxillary gland, and eye). In some multicellular tissues, PEPCK immunoreactivity was observed in multiple cell types. Several tissues (spleen, thyroid, and submaxillary gland) contained no detectable PEPCK immunoreactivity. During development, PEPCK immunoreactivity was associated with the developing nervous system and somites in 15-day embryos. At prenatal day 18, PEPCK immunoreactivity was detected only in the nervous system. At prenatal day 20, PEPCK immunoreactivity was observed in many of the tissues that contain PEPCK in the adult, with the exception of liver, lung, and stomach. PEPCK immunoreactivity was detected in liver at postnatal day 1, lung at postnatal day 7, and stomach after postnatal day 21. The only tissue in which PEPCK immunoreactivity decreased during development was the pancreas, where PEPCK immunoreactivity was detected at prenatal day 20 and was present until postnatal day 21. These results suggest that PEPCK expression is cell-type specific, more widespread than previously thought, and differentially expressed during development.

Developmental programmes of growth and survival in early sensory neurons

1991 ◽  
Vol 331 (1261) ◽  
pp. 259-262
Keyword(s):  
Nervous System ◽  
Sensory Neurons ◽  
Neurotrophic Factor ◽  
Target Distance ◽  
Trophic Factor ◽  
Growth And Survival ◽  
Target Field ◽  
Developing Nervous System

In the developing vertebrate nervous system the survival of neurons becomes dependent on the supply of a neurotrophic factor from their targets when their axons reach these targets. To determine how the onset of neurotrophic factor dependency is coordinated with the arrival of axons in the target field, we have studied the growth and survival of four populations of cranial sensory neurons whose axons have markedly different distances to grow to reach their targets. Axonal growth rate both in vivo and in vitro is related to target distance; neurons with more distant targets grow faster. The onset trophic factor dependency in culture is also related to target distance; neurons with more distant targets survive longer before becoming trophic factor dependent. These data suggest that programmes of growth and survival in early neurons play an important role in coordinating the timing of trophic interactions in the developing nervous system.

Central connections of sensory neurones from a hair plate proprioceptor in the thoraco-coxal joint of the locust.

1995 ◽  
Vol 198 (7) ◽  
pp. 1589-1601 ◽  
Author(s):  
F Kuenzi ◽  
M Burrows
Keyword(s):  
Stance Phase ◽  
Swing Phase ◽  
Motor Neurone ◽  
Sensory Neurone ◽  
Sensory Neurones ◽  
Selective Stimulation ◽  
Basal Joint ◽  
Motor Neurones ◽  
Individual Motor ◽  
Stimulation Of

The hair plate proprioceptors at the thoraco-coxal joint of insect limbs provide information about the movements of the most basal joint of the legs. The ventral coxal hair plate of a middle leg consists of group of 10-15 long hairs (70 microns) and 20-30 short hairs (30 microns). The long hairs are deflected by the trochantin as the leg is swung forward during the swing phase of walking, and their sensory neurones respond phasically during an imposed deflection and tonically if the deflection is maintained. Selective stimulation of the long hairs elicits a resistance reflex that rotates the coxa posteriorly and is similar to that occurring at the transition from the swing to the stance phase of walking. The motor neurones innervating the posterior rotator and adductor coxae muscles are excited, and those to the antagonistic anterior rotator muscle are inhibited. By contrast, selective stimulation of the short hairs leads only to a weak inhibition of the anterior rotator. The excitatory effects of the long hairs are mediated, in part, by direct connections between their sensory neurones and particular motor neurones. A spike in a sensory neurone elicits a short-latency depolarising postsynaptic potential (PSP) in posterior rotator and adductor motor neurones whose amplitude is enhanced by hyperpolarising current injected into the motor neurone. When the calcium in the saline is replaced with magnesium, the amplitude of the PSP is reduced gradually, and not abruptly as would be expected if an interneurone were interposed in the pathway. Several sensory neurones from long hairs converge to excite an individual motor neurone, evoking spikes in some motor neurones. The projections of the sensory neurones overlap with some of the branches of the motor neurones in the lateral association centre of the neuropile. It is suggested that these pathways would limit the extent of the swing phase of walking and contribute to the switch to the stance phase in a negative feedback loop that relieves the excitation of the hairs by rotating the coxa backwards.

Sign in / Sign up

Export Citation Format

Share Document