Effect of Epidural Stimulation on Muscle Activation and Sensory Perception

Author(s):  
2017 ◽  
Vol 118 (4) ◽  
pp. 2344-2357 ◽  
Author(s):  
Elisa J. Gonzalez-Rothi ◽  
Kristi A. Streeter ◽  
Marie H. Hanna ◽  
Anna C. Stamas ◽  
Paul J. Reier ◽  
...  

C2 spinal hemilesion (C2Hx) paralyzes the ipsilateral diaphragm, but recovery is possible through activation of “crossed spinal” synaptic inputs to ipsilateral phrenic motoneurons. We tested the hypothesis that high-frequency epidural stimulation (HF-ES) would potentiate ipsilateral phrenic output after subacute and chronic C2Hx. HF-ES (300 Hz) was applied to the ventrolateral C4 or T2 spinal cord ipsilateral to C2Hx in anesthetized and mechanically ventilated adult rats. Stimulus duration was 60 s, and currents ranged from 100 to 1,000 µA. Bilateral phrenic nerve activity and ipsilateral hypoglossal (XII) nerve activity were recorded before and after HF-ES. Higher T2 stimulus currents potentiated ipsilateral phasic inspiratory activity at both 2 and 12 wk post-C2Hx, whereas higher stimulus currents delivered at C4 potentiated ipsilateral phasic phrenic activity only at 12 wk ( P = 0.028). Meanwhile, tonic output in the ipsilateral phrenic nerve reached 500% of baseline values at the high currents with no difference between 2 and 12 wk. HF-ES did not trigger inspiratory burst-frequency changes. Similar responses occurred following T2 HF-ES. Increases in contralateral phrenic and XII nerve output were induced by C4 and T2 HF-ES at higher currents, but the relative magnitude of these changes was small compared with the ipsilateral phrenic response. We conclude that following incomplete cervical spinal cord injury, HF-ES of the ventrolateral midcervical or thoracic spinal cord can potentiate efferent phrenic motor output with little impact on inspiratory burst frequency. However, the substantial increases in tonic output indicate that the uninterrupted 60-s stimulation paradigm used is unlikely to be useful for respiratory muscle activation after spinal injury. NEW & NOTEWORTHY Previous studies reported that high-frequency epidural stimulation (HF-ES) activates the diaphragm following acute spinal transection. This study examined HF-ES and phrenic motor output following subacute and chronic incomplete cervical spinal cord injury. Short-term potentiation of phrenic bursting following HF-ES illustrates the potential for spinal stimulation to induce respiratory neuroplasticity. Increased tonic phrenic output indicates that alternatives to the continuous stimulation paradigm used in this study will be required for respiratory muscle activation after spinal cord injury.


1934 ◽  
Vol 29 (3) ◽  
pp. 350-352 ◽  
Author(s):  
George Van Ness Dearborn
Keyword(s):  

CounterText ◽  
2016 ◽  
Vol 2 (3) ◽  
pp. 283-306
Author(s):  
Tamara Brzostowska-Tereszkiewicz

Multisensory and cross-modal perception have been recognised as crucial for shaping modernist epistemology, aesthetics, and art. Illustrative examples of how it might be possible to test equivalences (or mutual translatability) between different sensual modalities can be found in theoretical pronouncements on the arts and in artistic production of both the avant-garde and high modernism. While encouraging multisensory, cross-modal, and multimodal artistic experiments, twentieth-century artists set forth a new language of sensory integration. This article addresses the problem of the literary representation of multisensory and cross-modal experience as a particular challenge for translation, which is not only a linguistic and cross-cultural operation but also cross-sensual, involving the gap between different culture-specific perceptual realities. The problem of sensory perception remains a vast underexplored terrain of modernist translation history and theory, and yet it is one with potentially far-reaching ramifications for both a cultural anthropology of translation and modernism's sensory anthropology. The framework of this study is informed by Douglas Robinson's somatics of translation and Clive Scott's perceptive phenomenology of translation, which help to put forth the notion of sensory equivalence as a pragmatic correspondence between the source and target texts, appealing to a range of somato-sensory (audial, visual, haptic, gestural, articulatory kinaesthetic, proprioceptive) modalities of reader response.


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