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. We also discuss the idea that the spinal cord is a major mechanism for supporting plasticity in the developing motor system. An implication of this research is that normally occurring sensory stimulation during the perinatal period influences the typical development and expression of action patterns, and that exploiting the developmental plasticity of the motor system may lead to improved strategies for promoting recovery of function in human infants with motor disorders.

Activation of the serotonin system has been shown to induce locomotor activity following a spinal cord transection. This study examines how the isolated spinal cord adapts to a sensory perturbation during activation of the serotonergic system. Real-time and persistent effects of a perturbation were examined in intact and spinal transected newborn rats. Rats received a spinal surgery (sham or low thoracic transection) on postnatal day 1 and were tested 9 days later. At test, subjects were treated with the serotonergic receptor agonist quipazine (3.0 mg/kg) to induce stepping behavior. Half of the subjects experienced range of motion (ROM) restriction during stepping, while the other half did not. Differences in stepping behavior (interlimb coordination) and limb trajectories (intralimb coordination) were found to occur in both intact and spinal subjects. Adaptations were seen in the forelimbs and hindlimbs. Also, real-time and persistent effects of ROM restriction (following removal of the perturbation) were seen in ROM-restricted subjects. This study demonstrates the sensitivity of the isolated spinal cord to sensory feedback in conjunction with serotonin modulation.

Multiple-choice questions are frequently used in college classrooms as part of student assessment. While multiple-choice assessments (compared to other formats such as constructed response) seem to be the preferred method of testing by instructors and students, their effectiveness in assessing comprehension in college courses is sometimes called into question. Research has shown that there are ways to optimize the construction and use of multiple-choice testing to benefit college classroom instruction and assessment, student learning, and performance, and to more efficiently utilize instructor's time and energy. This teacher-ready research review provides an overview of the research on utilizing multiple-choice questions as well as some tips on using, writing, and administering multiple-choice questions during assessments. We also summarize the benefits and potential issues with using multiple-choice questions including concerns about cheating, ways to detect and deter cheating, and testing issues and strategies unique to online formats. We hope that this short review will be helpful to instructors as they prepare courses and assessments and further encourage the use of empirical data in pedagogy related decision-making.

Quipazine is a 5-HT2A 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 pinch is an effective and robust method of sacrocaudal sensory afferent stimulation that induces motor activity, including alternating stepping. In this study, responsiveness to tail pinch following treatment with quipazine (or saline vehicle control) was examined in spinal cord transected (at mid-thoracic level) and intact neonatal rats. Rat pups were secured in the supine posture with limbs unrestricted. Quipazine or saline was administered intraperitoneally and after a 10-min period, a tail pinch was administered. A 1-min baseline period prior to tail pinch administration and a 1-min response period post-tail pinch was observed and hindlimb motor activity, including locomotor-like stepping behavior, was recorded and analyzed. Neonatal rats showed an immediate and robust response to sensory stimulation induced by tail pinch. Quipazine recovered hindlimb movement and step frequency in spinal rats back to intact levels, suggesting a synergistic, additive effect of 5-HT receptor and sensory stimulation in spinal rats. Although levels of activity in spinal rats were restored with quipazine, movement quality (high versus low amplitude) was only partially restored.

The development of postural control is considered an important factor for the expression of coordinated behavior such as locomotion. In the natural setting of the nest, newborn rat pups adapt their posture to perform behaviors of ecological relevance such as those related to suckling. The current study explores the role of posture in the expression of three behaviors in the newborn rat: spontaneous limb activity, locomotor-like stepping behavior, and the leg extension response (LER). One-day-old rat pups were tested in one of two postures – prone or supine – on each of these behavioral measures. Results showed that pups expressed more spontaneous activity while supine, more stepping while prone, and no differences in LER expression between the two postures. Together these findings show that posture affects the expression of newborn behavior patterns in different ways, and suggest that posture may act as a facilitator or a limiting factor in the expression of different behaviors during early development.