Synergistic action of gravity and temperature on the motor system within the lifespan: A “Baby Astronaut” hypothesis

Meigal, Alexander

doi:10.1016/j.mehy.2012.12.004

Cited by 16 publications

(31 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Both firing properties and synaptic inputs mature earlier in flexor MNs compared to extensor MNs1630. This distinction has been related to lowered gravitational influences and resultant reduced activity of antigravity muscles (i.e., extensor muscles) during the in utero life of mammalian foetuses3132. Our study reveals that this delay of extensor MN maturation also extends to their integrative synaptic properties, as indicated by the differential changes in ADSP forms.…”

Section: Discussionmentioning

confidence: 57%

Distinct and developmentally regulated activity-dependent plasticity at descending glutamatergic synapses on flexor and extensor motoneurons

Lenschow¹,

Cazalets²,

Bertrand³

2016

Sci Rep

View full text Add to dashboard Cite

Activity-dependent synaptic plasticity (ADSP) is paramount to synaptic processing and maturation. However, identifying the ADSP capabilities of the numerous synapses converging onto spinal motoneurons (MNs) remain elusive. Using spinal cord slices from mice at two developmental stages, 1–4 and 8–12 postnatal days (P1–P4; P8–P12), we found that high-frequency stimulation of presumed reticulospinal neuron axons in the ventrolateral funiculus (VLF) induced either an NMDA receptor-dependent-long-term depression (LTD), a short-term depression (STD) or no synaptic modulation in limb MNs. Our study shows that P1–P4 cervical MNs expressed the same plasticity profiles as P8–P12 lumbar MNs rather than P1–P4 lumbar MNs indicating that ADSP expression at VLF-MN synapses is linked to the rostrocaudal development of spinal motor circuitry. Interestingly, we observed that the ADSP expressed at VLF-MN was related to the functional flexor or extensor MN subtype. Moreover, heterosynaptic plasticity was triggered in MNs by VLF axon tetanisation at neighbouring synapses not directly involved in the plasticity induction. ADSP at VLF-MN synapses specify differential integrative synaptic processing by flexor and extensor MNs and could contribute to the maturation of spinal motor circuits and developmental acquisition of weight-bearing locomotion.

show abstract

Section: Discussionmentioning

confidence: 57%

Distinct and developmentally regulated activity-dependent plasticity at descending glutamatergic synapses on flexor and extensor motoneurons

Lenschow¹,

Cazalets²,

Bertrand³

2016

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The motor abilities of precocial species suggest that vestibular functions have matured in utero . Even though intrauterine cavity is similar to a microgravity environment (Wood, 1970; Sekulic et al, 2005; Meigal, 2013) because of neutral buoyancy in the amniotic fluid, the otoliths in the intrauterine environment are constantly exposed to the effects of gravity, and are stimulated by the linear accelerations induced by the movements of the mother (Ronca et al, 1993). In addition hair cells do not need the gravitational stimulus to develop.…”

Section: The Vestibular Development In Precocial or Altricial Speciesmentioning

confidence: 99%

The development of vestibular system and related functions in mammals: impact of gravity

Jamon

2014

Front. Integr. Neurosci.

View full text Add to dashboard Cite

This chapter reviews the knowledge about the adaptation to Earth gravity during the development of mammals. The impact of early exposure to altered gravity is evaluated at the level of the functions related to the vestibular system, including postural control, homeostatic regulation, and spatial memory. The hypothesis of critical periods in the adaptation to gravity is discussed. Demonstrating a critical period requires removing the gravity stimulus during delimited time windows, what is impossible to do on Earth surface. The surgical destruction of the vestibular apparatus, and the use of mice strains with defective graviceptors have provided useful information on the consequences of missing gravity perception, and the possible compensatory mechanisms, but transitory suppression of the stimulus can only be operated during spatial flight. The rare studies on rat pups housed on board of space shuttle significantly contributed to this problem, but the use of hypergravity environment, produced by means of chronic centrifugation, is the only available tool when repeated experiments must be carried out on Earth. Even though hypergravity is sometimes considered as a mirror situation to microgravity, the two situations cannot be confused because a gravitational force is still present. The theoretical considerations that validate the paradigm of hypergravity to evaluate critical periods are discussed. The question of adaption of graviceptor is questioned from an evolutionary point of view. It is possible that graviception is hardwired, because life on Earth has evolved under the constant pressure of gravity. The rapid acquisition of motor programming by precocial mammals in minutes after birth is consistent with this hypothesis, but the slow development of motor skills in altricial species and the plasticity of vestibular perception in adults suggest that gravity experience is required for the tuning of graviceptors. The possible reasons for this dichotomy are discussed.

show abstract

“…являются гравитация и более низкая температура, харак-терные для внеутробной жизни [25,26]. Нейрофизиологическая интерпретация полученных результатов базируется на данных, полученных при иссле-довании активности отдельных двигательных единиц (ДЕ) и иЭМГ.…”

Section: оригинальная статьяunclassified

“…Данные о параметрах иЭМГ недоношенных детей позво-ляют сделать предположение, что происходит внутриутроб-но, когда нерожденный ребенок еще погружен в около-плодные воды и фактически подвергается иммерсионной микрогравитации [26]. Выяснилось, что все нелинейные параметры иЭМГ у недоношенных детей примерно вдвое меньше по сравнению с доношенными сверстниками.…”

Section: оригинальная статьяunclassified

Development of an Infant’s Peripheral Motor System Within the First 3 Years of Life as Studied Using Surface Electromyography

Зарипова¹,

Мейгал²,

Макарова³

2015

Pediatr. farmakol.

View full text Add to dashboard Cite

Synergistic action of gravity and temperature on the motor system within the lifespan: A “Baby Astronaut” hypothesis

Cited by 16 publications

References 63 publications

Distinct and developmentally regulated activity-dependent plasticity at descending glutamatergic synapses on flexor and extensor motoneurons

Distinct and developmentally regulated activity-dependent plasticity at descending glutamatergic synapses on flexor and extensor motoneurons

The development of vestibular system and related functions in mammals: impact of gravity

Development of an Infant’s Peripheral Motor System Within the First 3 Years of Life as Studied Using Surface Electromyography

Contact Info

Product

Resources

About