Spinal Locomotion in Cats Following Spinal Cord Injury: A Prospective Study

This article aimed to evaluate the safety and efficacy of intensive neurorehabilitation in paraplegic cats, with no deep pain perception (grade 0 on the modified Frankel scale), with more than three months of injury. Nine cats, admitted to the Arrábida Veterinary Hospital/Arrábida Animal Rehabilitation Center (CRAA), were subjected to a 12-week intensive functional neurorehabilitation protocol, based on ground and underwater treadmill locomotor training, electrostimulation, and kinesiotherapy exercises, aiming to obtain a faster recovery to ambulation and a modulated locomotor pattern of flexion/extension. Of the nine cats that were admitted in this study, 56% (n = 5) recovered from ambulation, 44% of which (4/9) did so through functional spinal locomotion by reflexes, while one achieved this through the recovery of deep pain perception. These results suggest that intensive neurorehabilitation can play an important role in ambulation recovery, allowing for a better quality of life and well-being, which may lead to a reduction in the number of euthanasia procedures performed on paraplegic animals.

Unusual Quadrupedal Locomotion in Rat during Recovery from Lumbar Spinal Blockade of 5-HT7 Receptors

Coordination of four-limb movements during quadrupedal locomotion is controlled by supraspinal monoaminergic descending pathways, among which serotoninergic ones play a crucial role. Here we investigated the locomotor pattern during recovery from blockade of 5-HT7 or 5-HT2A receptors after intrathecal application of SB269970 or cyproheptadine in adult rats with chronic intrathecal cannula implanted in the lumbar spinal cord. The interlimb coordination was investigated based on electromyographic activity recorded from selected fore- and hindlimb muscles during rat locomotion on a treadmill. In the time of recovery after hindlimb transient paralysis, we noticed a presence of an unusual pattern of quadrupedal locomotion characterized by a doubling of forelimb stepping in relation to unaffected hindlimb stepping (2FL-1HL) after blockade of 5-HT7 receptors but not after blockade of 5-HT2A receptors. The 2FL-1HL pattern, although transient, was observed as a stable form of fore-hindlimb coupling during quadrupedal locomotion. We suggest that modulation of the 5-HT7 receptors on interneurons located in lamina VII with ascending projections to the forelimb spinal network can be responsible for the 2FL-1HL locomotor pattern. In support, our immunohistochemical analysis of the lumbar spinal cord demonstrated the presence of the 5-HT7 immunoreactive cells in the lamina VII, which were rarely 5-HT2A immunoreactive.

Behavioral changes in the brown planthopper, Nilaparvata lugens, mediated by melatonin

Background Melatonin has been proved to exist and play importance roles in rice plant, such as biosynthesis and resistance. However, little is known about the function of melatonin in its monophagous pest, the brown planthopper. Methods In this study, we examined the effects of melatonin on the copulatory and locomotor behaviors of brachypterous and macropterous adult planthoppers by exposing them to melatonin, luzindole (a melatonin receptor antagonist), or a combination of melatonin and luzindole. Results A total of 68.7% of copulation events occurred at night in the control, while 31.2% occurred at night in the melatonin treatment, which led to a decrease in offspring. Brachypterous males were involved in mating events in the melatonin treatment but not in the other two treatments or the control. The daily locomotor pattern in the melatonin treatment was markedly different from that in the luzindole and melatonin and luzindole treatments. The total locomotor activities of the macropterous and brachypterous males exposed with melatonin were suppressed compared to those in the control. Melatonin significantly decreased the daytime and nighttime locomotor activities of macropterous females. In comparison, the activity of brachypterous females decreased slightly in the daytime but was more than double that of the control females at night. Conclusions Our results reveal that melatonin plays a role in the behaviors of brown planthoppers.

Locomotion-induced ocular motor behavior in larval Xenopus is developmentally tuned by visuo-vestibular reflexes

Locomotion requires neural computations to maintain stable perception of the world despite disturbing consequences of the motor behavior on sensory stability. The developmental establishment of locomotor proficiency is therefore accompanied by a concurrent maturation of gaze-stabilizing motor behaviors. Using developing Xenopus larvae, we demonstrate mutual plasticity of predictive spinal locomotor efference copies and multi-sensory motion signals with the aim to constantly ensure dynamically adequate eye movements during swimming. Following simultaneous ontogenetic onsets of locomotion, spino-ocular, optokinetic and otolith-ocular motor behaviors, locomotor efference copy-driven eye movements improve through gradually augmenting influences of semicircular canal signals. Accordingly, neuronal computations change from predominating cancelation of angular vestibulo-ocular reflexes by locomotor efference copies in young larvae to summation of these signals in older larvae. The developmental switch occurs in synchrony with the reduced efficacy of the tail-undulatory locomotor pattern generator causing gradually declining influences on the ocular motor output.

Locomotion-induced ocular motor behavior in larval Xenopus is developmentally tuned by visuo-vestibular reflexes

ABSTRACTLocomotion requires neural computations to maintain stable perception of the world despite disturbing consequences of the motor behavior on sensory stability. The developmental establishment of locomotor proficiency is therefore accompanied by a concurrent maturation of gaze-stabilizing motor behaviors. Using developing larval Xenopus, we demonstrate mutual plasticity of predictive spinal locomotor efference copies and multi-sensory motion signals with the aim to constantly ensure dynamically adequate eye movements during swimming. Following simultaneous ontogenetic onsets of locomotion, spino-ocular, optokinetic and otolith-ocular motor behaviors, locomotor efference copy-driven eye movements improve through gradually augmenting influences of semicircular canal signals. Accordingly, neuronal computations change from a predominating cancelation of angular vestibulo-ocular reflexes by locomotor efference copies in young larvae to a summation of these signals in older larvae. The developmental switch occurs in synchrony with a reduced efficacy of the tail-undulatory locomotor pattern generator causing gradually decaying influences on the ocular motor output.

Evidence for habitual climbing in a Pleistocene hominin in South Africa

Bipedalism is a defining trait of the hominin lineage, associated with a transition from a more arboreal to a more terrestrial environment. While there is debate about when modern human-like bipedalism first appeared in hominins, all known South African hominins show morphological adaptations to bipedalism, suggesting that this was their predominant mode of locomotion. Here we present evidence that hominins preserved in the Sterkfontein Caves practiced two different locomotor repertoires. The trabecular structure of a proximal femur (StW 522) attributed to Australopithecus africanus exhibits a modern human-like bipedal locomotor pattern, while that of a geologically younger specimen (StW 311) attributed to either Homo sp. or Paranthropus robustus exhibits a pattern more similar to nonhuman apes, potentially suggesting regular bouts of both climbing and terrestrial bipedalism. Our results demonstrate distinct morphological differences, linked to behavioral differences between Australopithecus and later hominins in South Africa and contribute to the increasing evidence of locomotor diversity within the hominin clade.