Relation Between the Frequency of Short-Pulse Electrical Stimulation of Afferent Nerve Fibers and Evoked Muscle Force

2017 ◽  
Vol 64 (11) ◽  
pp. 2737-2745 ◽  
Keyword(s):  
Electrical Stimulation ◽  
Muscle Force ◽  
Short Pulse ◽  
Nerve Fibers ◽  
Afferent Nerve ◽  
Afferent Nerve Fibers ◽  
Stimulation Of

Depression of Nociceptive Sensory Activity in the Rat Spinal Cord Due to the Intrathecal Administration of Drugs: Effect of Diazepam

Neurosurgery ◽  
1984 ◽  
Vol 15 (6) ◽  
pp. 917-920 ◽  
Author(s):  
Ilmar Jurna
Keyword(s):  
Spinal Cord ◽  
Substance P ◽  
Nerve Fibers ◽  
Afferent Nerve ◽  
Spinal Reflexes ◽  
Sensory Response ◽  
Motor Responses ◽  
Afferent Nerve Fibers ◽  
C Fiber ◽  
Stimulation Of

Abstract The intrathecal (i.t.) administration of morphine inhibits nociceptive motor responses and activity in ascending axons evoked by stimulation of nociceptive afferent nerve fibers (nociceptive sensory response) in the rat. The i.t. administration of cholecystokinin octapeptide and ceruletide inhibits nociceptive motor responses, but does not affect ascending nociceptive activity. This shows that drug-induced depression of nociceptive motor responses is not always associated with depression of the nociceptive sensory response of the spinal cord. The microiontophoretic application of substance P excites single dorsal horn neurons that respond to noxious stimulation, whereas the i.t. administration of substance P inhibits both nociceptive motor and sensory responses. Thus, the results obtained from the i.t. administration of a drug may differ from those obtained from its application to single spinal neurons. Diazepam inhibits spinal reflexes and may reduce pain sensation in humans. To assess whether a spinal action is involved in the pain-relieving effect of diazepam, experiments were carried out on spinalized rats in which activity evoked by the stimulation of nociceptive and nonnociceptive afferent nerve fibers of the sural nerve was recorded from single ascending axons below the site of spinal cord transection. Diazepam, 20 ųg i.t., reduced activity evoked by afferent A delta and C fiber stimulation and by stimulation of afferent A beta fibers. The depressant effect caused by diazepam, 2 mg/kg i.v., on C fiber-evoked ascending activity was reduced by the i.t. injection of the benzodiazepine antagonist, Ro 15-1788 (40 ųg), an imidazodiazepine. It is concluded that the depression by diazepam of C fiber-evoked ascending activity contributes to pain relief caused by the drug.

scholarly journals Discriminability of multiple cutaneous and proprioceptive hand percepts evoked by intraneural stimulation with Utah slanted electrode arrays in human amputees

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
David M. Page ◽  
Jacob A. George ◽  
Suzanne M. Wendelken ◽  
Tyler S. Davis ◽  
David T. Kluger ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Sensory Feedback ◽  
Functional Performance ◽  
Nerve Fibers ◽  
Stimulation Frequency ◽  
Psychological Benefits ◽  
Electrode Arrays ◽  
Afferent Nerve Fibers ◽  
Sense Of Touch ◽  
Stimulation Of

Abstract Background Electrical stimulation of residual afferent nerve fibers can evoke sensations from a missing limb after amputation, and bionic arms endowed with artificial sensory feedback have been shown to confer functional and psychological benefits. Here we explore the extent to which artificial sensations can be discriminated based on location, quality, and intensity. Methods We implanted Utah Slanted Electrode Arrays (USEAs) in the arm nerves of three transradial amputees and delivered electrical stimulation via different electrodes and frequencies to produce sensations on the missing hand with various locations, qualities, and intensities. Participants performed blind discrimination trials to discriminate among these artificial sensations. Results Participants successfully discriminated cutaneous and proprioceptive sensations ranging in location, quality and intensity. Performance was significantly greater than chance for all discrimination tasks, including discrimination among up to ten different cutaneous location-intensity combinations (15/30 successes, p < 0.0001) and seven different proprioceptive location-intensity combinations (21/40 successes, p < 0.0001). Variations in the site of stimulation within the nerve, via electrode selection, enabled discrimination among up to five locations and qualities (35/35 successes, p < 0.0001). Variations in the stimulation frequency enabled discrimination among four different intensities at the same location (13/20 successes, p < 0.0005). One participant also discriminated among individual stimulation of two different USEA electrodes, simultaneous stimulation on both electrodes, and interleaved stimulation on both electrodes (20/24 successes, p < 0.0001). Conclusion Electrode location, stimulation frequency, and stimulation pattern can be modulated to evoke functionally discriminable sensations with a range of locations, qualities, and intensities. This rich source of artificial sensory feedback may enhance functional performance and embodiment of bionic arms endowed with a sense of touch.

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