Onset of neonatal locomotor behavior and the mechanical development of Achilles and tail tendons.

Tendon tissue engineering approaches are challenged by a limited understanding of the role mechanical loading plays in normal tendon development. We propose that the increased loading that developing postnatal tendons experience with the onset of locomotor behavior impacts tendon formation. The objective of this study was to assess the onset of spontaneous weight-bearing locomotion in postnatal day (P) 1, 5, and 10 rats, and characterize the relationship between locomotion and the mechanical development of weight-bearing and non-weight-bearing tendons.

Locomotion and posture development in immature male and female rats (Rattus norvegicus): Comparison of sensory-enriched versus sensory-deprived testing environments.

The aim of the current study was to provide normative data on spontaneous locomotion and posture behavior in developing rats (Rattus norvegicus), during the first 2 postnatal weeks. Male and female rat pups were tested daily from P1 (postnatal day 1; ∼24 hr after birth) to P15 in a sensory-enriched or sensory-deprived testing environment, which was enclosed in a temperature-controlled incubator. Pups in the sensory-deprived condition were tested individually and placed in a square, Plexiglas box (open-field) for a 20-min test period.

Histamine modulates spinal motoneurons and locomotor circuits.

Spinal motoneurons and locomotor networks are regulated by monoamines, among which, the contribution of histamine has yet to be fully addressed. The present study investigates histaminergic regulation of spinal activity, combining intra- and extracellular electrophysiological recordings from neonatal rat spinal cord in vitro preparations. Histamine dose-dependently and reversibly generated motoneuron depolarization and action potential firing.

The Reciprocity Team: Development of an Interprofessional Research Collaboration.

The purpose of this article is to articulate and provide detail about an interprofessional research collaboration at a public university in a rural area of western United States. This interprofessional research collaboration was organized to explore infant and maternal reciprocity. As a part of the organization and process portion of the collaborative effort, the authors identify the unique attributes of their collaboration.

Stimulation of 5-HT2A receptors recovers sensory responsiveness in acute spinal neonatal rats.

Quipazine is a 5-HT-receptor agonist that has been used to induce motor activity and promote recovery of function after spinal cord injury in neonatal and adult rodents. Sensory stimulation also activates sensory and motor circuits and promotes recovery after spinal cord injury. In rats, tail pinching is an effective and robust method of sacrocaudal sensory afferent stimulation that induces motor activity, including alternating stepping.

Serotonergic activation of locomotor behavior and posture in one-day old rats.

The purpose of this study was to determine what dose of quipazine, a serotonergic agonist, facilitates air-stepping and induces postural control and patterns of locomotion in newborn rats. Subjects in both experiments were 1-day-old rat pups. In Experiment 1, pups were restrained and tested for air-stepping in a 35-min test session.

Developmental plasticity of coordinated action patterns in the perinatal rat.

Some of the most simple, stereotyped, reflexive, and spinal-mediated motor behaviors expressed by animals display a level of flexibility and plasticity that is not always recognized. We discuss several examples of how coordinated action patterns have been shown to be flexible and adaptive in response to sensory feedback. We focus on interlimb and intralimb coordination during the expression of two action patterns (stepping and the leg extension response) in newborn rats, as well as interlimb motor learning.