Defecation Induced by Stimulation of Sacral S2 Spinal Root in Cats

2021 ◽  
Author(s):  
Jicheng Wang ◽  
Zhijun Shen ◽  
Bing Shen ◽  
Jianan Jian ◽  
Travis Hannan ◽  
...  
Keyword(s):  
Distal Colon ◽  
Spinal Nerve ◽  
Ventral Root ◽  
Spinal Root ◽  
Balloon Catheters ◽  
Minimally Invasive Surgical ◽  
Lead Electrode ◽  
Cord Injury ◽  
Minute Duration ◽  
Stimulation Of

The aim of this study was to determine if stimulation of sacral spinal nerve roots can induce defecation in cats. In anesthetized cats, bipolar hook electrodes were placed on the S1-S3 dorsal and/or ventral roots. Stimulus pulses (1-50 Hz, 0.2 ms) were applied to an individual S1-S3 root to induce proximal/distal colon contractions and defecation. Balloon catheters were inserted into the proximal and distal colon to measure contraction pressure. Glass marbles were inserted into the rectum to demonstrate defecation by videotaping the elimination of marbles. Stimulation of the S2 ventral root at 7 Hz induced significantly (p<0.05) larger contractions (32±9 cmH2O) in both proximal and distal colon than stimulation of the S1 or S3 ventral root. Intermittent (5 times) stimulation (1 minute on and 1 minute off) of both dorsal and ventral S2 roots at 7 Hz produced reproducible colon contractions without fatigue, while continuous stimulation of 5-minute duration caused significant fatigue in colon contractions. Stimulation (7 Hz) of both dorsal and ventral S2 roots together successfully induced defecation that eliminated 1-2 marbles from the rectum. This study indicates the possibility to develop a novel neuromodulation device to restore defecation function after spinal cord injury using a minimally invasive surgical approach to insert a lead electrode via the sacral foramen to stimulate a sacral spinal root.

Clinical study of reconstructed bladder innervation below the level of spinal cord injury to produce urination by Achilles tendon–to-bladder reflex contractions

2009 ◽  
Vol 10 (5) ◽  
pp. 452-457 ◽  
Author(s):  
Haodong Lin ◽  
Chunlin Hou ◽  
Xianyou Zhen ◽  
Zhen Xu
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Achilles Tendon ◽  
Neurogenic Bladder ◽  
External Sphincter ◽  
Ventral Root ◽  
Clinical Approach ◽  
Spinal Root ◽  
Cord Injury

Object Neurogenic bladder dysfunction following spinal cord injury (SCI) is a major medical and social problem for which there is no ideal treatment strategy. In the present study, the authors analyze the effectiveness of neurogenic bladder reinnervation in patients with SCIs by using Achilles tendon reflexes below the paraplegic level. Methods Spinal root anastomoses were performed in 12 paraplegic patients with hyperreflexic neurogenic bladder and detrusor external sphincter dyssynergia (DESD) caused by complete suprasacral SCI, in an attempt to reinnervate the bladder. The surgery anastomosed the unilateral proximal end of the S-1 ventral root and the distal end of the S-2 and/or S-3 ventral roots to build the Achilles tendon–to-bladder reflex, while the S-1 dorsal root was kept intact as the trigger for micturition after axonal regeneration. All patients underwent urodynamic evaluation before surgery and at follow-up. Results The mean follow-up duration was 3 years. Of the 12 patients, 9 (75%) regained satisfactory bladder control within 6 to 12 months after ventral root microanastomosis. In these 9 patients, urodynamic studies revealed a change from detrusor hyperreflexia with DESD and high detrusor pressure to almost normal storage and synergic voiding without DESD. The average bladder capacity increased from 258 ± 33 ml to 350 ± 49 ml, residual urine decreased from 214 ± 36 ml to 45 ± 11 ml, and urinary infections were not observed. Patients with impaired renal function experienced a full recovery. Three patients failed to show any improvement after the operation. Conclusions These results suggest the effectiveness of bladder innervation below the level of SCI to produce urination by Achilles tendon–to-bladder reflex contractions, and might therefore provide a new clinical approach to reconstructing spasmodic bladder urination function.

Drastic Decrease in Isoflurane Minimum Alveolar Concentration and Limb Movement Forces after Thoracic Spinal Cooling and Chronic Spinal Transection in Rats

2005 ◽  
Vol 102 (3) ◽  
pp. 624-632 ◽  
Author(s):  
Steven L. Jinks ◽  
Carmen L. Dominguez ◽  
Joseph F. Antognini
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Minimum Alveolar Concentration ◽  
Tail Flick ◽  
Noxious Stimulation ◽  
Partial Recovery ◽  
Spinal Transection ◽  
Thoracic Spinal ◽  
Cord Injury ◽  
Stimulation Of

Background Individuals with spinal cord injury may undergo multiple surgical procedures; however, it is not clear how spinal cord injury affects anesthetic requirements and movement force under anesthesia during both acute and chronic stages of the injury. Methods The authors determined the isoflurane minimum alveolar concentration (MAC) necessary to block movement in response to supramaximal noxious stimulation, as well as tail-flick and hind paw withdrawal latencies, before and up to 28 days after thoracic spinal transection. Tail-flick and hind paw withdrawal latencies were measured in the awake state to test for the presence of spinal shock or hyperreflexia. The authors measured limb forces elicited by noxious mechanical stimulation of a paw or the tail at 28 days after transection. Limb force experiments were also conducted in other animals that received a reversible spinal conduction block by cooling the spinal cord at the level of the eighth thoracic vertebra. Results A large decrease in MAC (to &lt;/= 40% of pretransection values) occurred after spinal transection, with partial recovery (to approximately 60% of control) at 14-28 days after transection. Awake tail-flick and hind paw withdrawal latencies were facilitated or unchanged, whereas reflex latencies under isoflurane were depressed or absent. However, at 80-90% of MAC, noxious stimulation of the hind paw elicited ipsilateral limb withdrawals in all animals. Hind limb forces were reduced (by &gt;/= 90%) in both chronic and acute cold-block spinal animals. Conclusions The immobilizing potency of isoflurane increases substantially after spinal transection, despite the absence of a baseline motor depression, or "spinal shock." Therefore, isoflurane MAC is determined by a spinal depressant action, possibly counteracted by a supraspinal facilitatory action. The partial recovery in MAC at later time points suggests that neuronal plasticity after spinal cord injury influences anesthetic requirements.

Epidural electrical stimulation to facilitate locomotor recovery after spinal cord injury

2021 ◽  
Author(s):  
Johannie Audet ◽  
Charly G. Lecomte
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Electrical Stimulation ◽  
Clinical Implementation ◽  
Preclinical Models ◽  
Lumbosacral Region ◽  
Locomotor Recovery ◽  
Promising Therapeutic Approach ◽  
Cord Injury ◽  
Stimulation Of

Tonic or phasic electrical epidural stimulation of the lumbosacral region of the spinal cord facilitates locomotion and standing in a variety of preclinical models with severe spinal cord injury. However, the mechanisms of epidural electrical stimulation that facilitate sensorimotor functions remain largely unknown. This review aims to address how epidural electrical stimulation interacts with spinal sensorimotor circuits and discusses the limitations that currently restrict the clinical implementation of this promising therapeutic approach.

ATP concentrations and muscle tension increase linearly with muscle contraction

2003 ◽  
Vol 95 (2) ◽  
pp. 577-583 ◽  
Author(s):  
Jianhua Li ◽  
Nicholas C. King ◽  
Lawrence I. Sinoway
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Contraction ◽  
Motor Nerve ◽  
Muscle Tension ◽  
Nerve Fibers ◽  
Ventral Root ◽  
Ventral Roots ◽  
Root Stimulation ◽  
Stimulation Of

Previous studies have suggested that activation of ATP-sensitive P2X receptors in skeletal muscle play a role in mediating the exercise pressor reflex (Li J and Sinoway LI. Am J Physiol Heart Circ Physiol 283: H2636–H2643, 2002). To determine the role ATP plays in this reflex, it is necessary to examine whether muscle interstitial ATP (ATPi) concentrations rise with muscle contraction. Accordingly, in this study, muscle contraction was evoked by electrical stimulation of the L7 and S1 ventral roots of the spinal cord in 12 decerebrate cats. Muscle ATPi was collected from microdialysis probes inserted in the muscle. ATP concentrations were determined by the HPLC method. Electrical stimulation of the ventral roots at 3 and 5 Hz increased mean arterial pressure by 13 ± 2 and 16 ± 3 mmHg ( P < 0.05), respectively, and it increased ATP concentration in contracting muscle by 150% ( P < 0.05) and 200% ( P < 0.05), respectively. ATP measured in the opposite control limb did not rise with ventral root stimulation. Section of the L7 and S1 dorsal roots did not affect the ATPi seen with 5-Hz ventral root stimulation. Finally, ventral roots stimulation sufficient to drive motor nerve fibers did not increase ATP in previously paralyzed cats. Thus ATPi is not largely released from sympathetic or motor nerves and does not require an intact afferent reflex pathway. We conclude that ATPi is due to the release of ATP from contracting skeletal muscle cells.

scholarly journals An objective approach to assess colonic pain in mice using colonometry

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0245410
Author(s):  
Liya Y. Qiao ◽  
Jonathan Madar
Keyword(s):  
Neurological Disorders ◽  
Stretch Reflex ◽  
Distal Colon ◽  
Saline Infusion ◽  
Noxious Stimulation ◽  
Trinitrobenzene Sulfonic Acid ◽  
Primary Afferent ◽  
Reflex Pathways ◽  
Constant Rate ◽  
Stimulation Of

The present study presents a non-surgical approach to assess colonic mechanical sensitivity in mice using colonometry, a technique in which colonic stretch-reflex contractions are measured by recording intracolonic pressures during saline infusion into the distal colon in a constant rate. Colonometrical recording has been used to assess colonic function in healthy individuals and patients with neurological disorders. Here we found that colonometry can also be implemented in mice, with an optimal saline infusion rate of 1.2 mL/h. Colonometrograms showed intermittent pressure rises that was caused by periodical colonic contractions. In the sceneries of colonic hypersensitivity that was generated post 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colonic inflammation, following chemogenetic activation of primary afferent neurons, or immediately after noxious stimulation of the colon by colorectal distension (CRD), the amplitude of intracolonic pressure (AICP) was markedly elevated which was accompanied by a faster pressure rising (ΔP/Δt). Colonic hypersensitivity-associated AICP elevation was a result of the enhanced strength of colonic stretch-reflex contraction which reflected the heightened activity of the colonic sensory reflex pathways. The increased value of ΔP/Δt in colonic hypersensitivity indicated a lower threshold of colonic mechanical sensation by which colonic stretch-reflex contraction was elicited by a smaller saline infusion volume during a shorter period of infusion time. Chemogenetic inhibition of primary afferent pathway that was governed by Nav1.8-expressing cells attenuated TNBS-induced up-regulations of AICP, ΔP/Δt, and colonic pain behavior in response to CRD. These findings support that colonometrograms can be used for analysis of colonic pain in mice.

Survival, regeneration and functional recovery of motoneurons in adult rats by reimplantation of ventral root following spinal root avulsion

2004 ◽  
Vol 19 (8) ◽  
pp. 2123-2131 ◽  
Author(s):  
Huai-Yu Gu ◽  
Hong Chai ◽  
Jian-Yi Zhang ◽  
Zhi-Bin Yao ◽  
Li-Hua Zhou ◽  
...  
Keyword(s):  
Functional Recovery ◽  
Ventral Root ◽  
Root Avulsion ◽  
Spinal Root ◽  
Adult Rats
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