Long-term alteration of leg position due to shock avoidance by spinal rats

Buerger, A. A.; Fennessy, A.

doi:10.1016/s0014-4886(71)80001-8

Cited by 27 publications

(12 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other studies of spinally transected animals are consistent with a significant level of plasticity of the spinal circuitry associated with hindlimb function (Buerger and Fennessy, 1971;Grau et al, 1998). Furthermore, operant conditioning experiments showed that monkeys and rats can be trained to decrease or increase hindlimb Hoffman reflex responses, although this training is not linked to practice of a motor task Wolpaw, 1995, 1997;Chen et al, 1999).…”

mentioning

confidence: 69%

Use-Dependent Modulation of Inhibitory Capacity in the Feline Lumbar Spinal Cord

Tillakaratne¹,

Leon²,

Hoang³

et al. 2002

J. Neurosci.

189

171

View full text Add to dashboard Cite

The ability to perform stepping and standing can be reacquired after complete thoracic spinal cord transection in adult cats with appropriate, repetitive training. We now compare GAD(67)A levels in the spinal cord of cats that were trained to step or stand. We confirmed that a complete spinal cord transection at approximately T12 increases glutamic acid decarboxylase (GAD)(67) in both the dorsal and ventral horns of L5-L7. We now show that step training decreases these levels toward control. Kinematic analyses show that this downward modulation is correlated inversely with stepping ability. Compared with intact cats, spinal cord-transected cats had increased punctate GAD(67) immunoreactivity around neurons in lamina IX at cord segments L5-L7. Compared with spinal nontrained cats, those trained to stand on both hindlimbs had more GAD(67) puncta bilaterally in a subset of lamina IX neurons. In cats trained to stand unilaterally, this elevated staining pattern was limited to the trained side and extended for at least 4 mm in the L6 and L7 segments. The location of this asymmetric GAD(67) staining corresponded to the motor columns of primary knee flexors, which are minimally active during standing, perhaps because of extensor-activated inhibitory interneuron projections. The responsiveness to only a few days of motor training, as well as the GABA-synthesizing potential in the spinal cord, persists for at least 25 months after the spinal cord injury. This modulation is specific to the motor task that is performed repetitively and is closely linked to the ability of the animal to perform a specific motor task.

show abstract

mentioning

confidence: 69%

Use-Dependent Modulation of Inhibitory Capacity in the Feline Lumbar Spinal Cord

Tillakaratne¹,

Leon²,

Hoang³

et al. 2002

J. Neurosci.

189

171

View full text Add to dashboard Cite

show abstract

“…The question addressed in the present study, therefore, was whether bipedal step-training (StepTr) or unipedal hindlimb stand-training (Stand-Tr) in neonatal spinally transected rats changed the potential to perform a novel, acute instrumental spinal learning task relative to non-trained (Non-Tr) rats [3,4,6,7,25,27]. During the 30 min instrumental learning task, spinally transected rats receive shock to the tibialis anterior (TA) muscle whenever the leg is extended, and learn to maintain the leg in a flexed position, thereby minimizing net shock exposure [25].…”

Section: Introductionmentioning

confidence: 99%

Two chronic motor training paradigms differentially influence acute instrumental learning in spinally transected rats

Bigbee

Crown

Ferguson

et al. 2007

Behavioural Brain Research

View full text Add to dashboard Cite

The effect of two chronic motor training paradigms on the ability of the lumbar spinal cord to perform an acute instrumental learning task was examined in neonatally (postnatal day 5; P5) spinal cord transected (i.e., spinal) rats. At ∼P30, rats began either unipedal hindlimb stand training (Stand-Tr; 20-25 min/day, 5 days/wk), or bipedal hindlimb step training (Step-Tr; 20 min/day; 5 days/wk) for 7 wks. Non-trained spinal rats (Non-Tr) served as controls. After 7 wks all groups were tested on the flexor-biased instrumental learning paradigm. We hypothesized that 1) Step-Tr rats would exhibit an increased capacity to learn the flexor-biased task relative to Non-Tr subjects, as locomotion involves repetitive training of the tibialis anterior (TA), the ankle flexor whose activation is important for successful instrumental learning, and 2) Stand-Tr rats would exhibit a deficit in acute motor learning, as unipedal training activates the ipsilateral ankle extensors, but not flexors. Results showed no differences in acute learning potential between Non-Tr and Step-Tr rats, while the Stand-Tr group showed a reduced capacity to learn the acute task. Further investigation of the Stand-Tr group showed that, while both the ipsilateral and contralateral hindlimbs were significantly impaired in their acute learning potential, the contralateral, untrained hindlimbs exhibited significantly greater learning deficits. These results suggest that different types of chronic peripheral input may have a significant impact on the ability to learn a novel motor task, and demonstrate the potential for experiencedependent plasticity in the spinal cord in the absence of supraspinal connectivity.

show abstract

“…Central sensitization produces a lasting increase in behavioral reactivity that has been linked to the development of neuropathic pain (Treede et al 1992). Other studies showed that spinal cord neurons are sensitive to stimulus (Pavlovian) relations (Fitzgerald and Thompson 1967;Patterson et al 1973;Beggs et al 1983) and that the vigor of a spinal reflex is modified by its consequences (instrumental learning; Buerger and Fennessy 1970;Chopin and Buerger 1976;Grau et al 1998). These effects appear to be mediated by some of the same neurochemical mechanisms implicated in neurobiological models of learning and memory within the brain (Harris et al 1984;Morris et al 1986).…”

Section: Introductionmentioning

confidence: 99%

“…Recent studies have challenged this perspective, demonstrating that spinal cord neurons can support some complex behaviors (e.g., stepping) and simple forms of learning (Fitzgerald and Thompson 1967;Buerger and Fennessy 1970;Patterson et al 1973;Chopin and Buerger 1976;Beggs et al 1983;Edgerton et al 1992;Grau et al 1998). An example of spinal learning is observed in the pain system, where stimuli that engage pain (nociceptive) fibers can sensitize spinal neurons, a phenomenon known as central sensitization (Woolf 1983).…”

Section: Introductionmentioning

confidence: 99%

Exposure to intermittent nociceptive stimulation under pentobarbital anesthesia disrupts spinal cord function in rats

et al. 2007

View full text Add to dashboard Cite

Rationale-Spinal cord plasticity can be assessed in spinal rats using an instrumental learning paradigm in which subjects learn an instrumental response, hindlimb flexion, to minimize shock exposure. Prior exposure to uncontrollable intermittent stimulation blocks learning in spinal rats but has no effect if given before spinal transection, suggesting that supraspinal systems modulate nociceptive input to the spinal cord, rendering it less susceptible to the detrimental consequences of uncontrollable stimulation.Objective-The present study examines whether disrupting brain function with pentobarbital blocks descending inhibitory systems that normally modulate nociceptive input, making the spinal cord more sensitive to the adverse effect of uncontrollable intermittent stimulation. Materials and methods-MaleSprague-Dawley rats received uncontrollable intermittent stimulation during pentobarbital anesthesia after (experiment 1) or before (experiment 2) spinal cord transection. They were then tested for instrumental learning at a later time point. Experiment 3 examined whether these manipulations affected nociceptive (thermal) thresholds.Results-Experiment 1 showed that pentobarbital had no effect on the induction of the learning deficit after spinal cord transection. Experiment 2 showed that intact rats anesthetized during uncontrollable intermittent stimulation failed to learn when later transected and tested for instrumental learning. Experiment 3 found that uncontrollable intermittent stimulation induced an antinociception in intact subjects that was blocked by pentobarbital. Conclusions-The results suggest a surgical dose of pentobarbital (50 mg/kg) suppresses supraspinal (experiment 2) but not spinal (experiment 1) systems that modulate nociceptive input to the spinal cord by blocking the antinociception that is induced by this input (experiment 3).

show abstract

Long-term alteration of leg position due to shock avoidance by spinal rats

Cited by 27 publications

References 18 publications

Use-Dependent Modulation of Inhibitory Capacity in the Feline Lumbar Spinal Cord

Use-Dependent Modulation of Inhibitory Capacity in the Feline Lumbar Spinal Cord

Two chronic motor training paradigms differentially influence acute instrumental learning in spinally transected rats

Exposure to intermittent nociceptive stimulation under pentobarbital anesthesia disrupts spinal cord function in rats

Contact Info

Product

Resources

About