Related Experiment Videos
Development of righting when falling from a bipedal standing posture: evidence for the dissociation of dynamic and
1Department of Psychology, University of Lethbridge, Alberta, Canada.
Insights
Rat pups develop righting reflexes differently based on sensory input. Air righting emerges later than ground righting, suggesting neural mechanisms mature based on context, not just sensory systems.
Area of Science:
- Developmental neuroscience
- Animal behavior
- Sensory processing
Background:
- Righting reflexes in rats are crucial for survival.
- Contact righting (on ground) is present at birth, while air righting (in air) emerges later.
- Sensory inputs differ between ground (vestibular, proprioceptive-tactile) and air (vestibular only) righting.
Purpose of the Study:
- To investigate the developmental basis of righting reflexes in rats.
- To determine if sensory input differences or neural maturation drive developmental timing of righting.
- To differentiate between context-specific (falling vs. stationary) and sensory-specific righting mechanisms.
Main Methods:
- Pups were tested for righting reflexes after being pushed backward from a bipedal stance.
- This method provided proprioceptive-tactile information during a fall.
- Developmental onset and maturation of this bipedal righting were compared to air and contact righting.
Main Results:
- Righting from a bipedal fall developed similarly to air righting, not contact righting.
- This suggests neural mechanisms for acceleratory (falling) righting mature differently from stationary righting.
- Some evidence indicates a dissociation between vestibular-only and combined vestibular/proprioceptive-tactile righting development.
Conclusions:
- The developmental timing of righting reflexes is primarily determined by the context of the righting event (falling vs. stationary), not solely by the sensory systems involved.
- Neural systems appear organized for specific righting contexts.
- Righting systems may require classification based on both sensory input and the context of the righting maneuver.
Abstract:
Righting to prone when placed supine on the ground by rats is present at birth, albeit in incomplete form. In contrast, righting in the air when falling from the supine position does not begin to emerge until the end of the first week and is not complete until the end of the third week postnatally. On the ground, the animals have sensory information from proprioceptive-tactile sources, as well as vestibular; in the air, they have only vestibular. Thus, it is possible that the difference between contact righting and air righting is a reflection of the relative difference in the maturation of tactile vs. vestibular mechanisms. In this study, pups were tested by pushing them backwards from a bipedal standing position. Such a context provided proprioceptive-tactile information during the fall. The results showed that the developmental onset and maturation of righting from the bipedal position resembled that of air righting rather than contact righting. This suggests that the difference between air righting and contact righting is not due to differences in sensory inputs, but to differential maturation of neural mechanisms for acceleratory (i.e., falling) vs. stationary (i.e., lying on the ground) forms of righting. That is, the appropriate neural systems are organized for the type of righting, not for the sensory systems used. Even so, some evidence is provided suggesting a developmental dissociation between righting from falling with vestibular information only, and with proprioceptive-tactile information in addition. Therefore, righting systems appear to need two dimensions of classification--one based on sensory systems involved, and the other in terms of the context of righting (i.e., falling vs. stationary).