Nerve Electrode Research Articles

Increased Fiber Excitability Does Not Contribute to Post‐Tetanic Potentiation in Mice

PurposePost‐tetanic potentiation (PTP) is the enhancement of twitch force following tetanic stimulation and is an important component when studying skeletal muscle physiology and plasticity. Mechanistically, it is plausible that PTP could be associated with an increase in fiber excitability and/or any event following sarcoplasmic reticulum (SR) calcium release (i.e., at the contractile apparatus). Therefore, the goal of this study was to determine if increased fiber excitability contributes to PTP.MethodsAdult female C57BL/6J mice were chronically implanted with stimulating electrodes on the left common peroneal nerve and electromyographic (EMG) electrodes on the left tibialis anterior (TA) muscle. Following surgical recovery (at least 2 weeks after EMG electrode implantation), in vivo PTP of the anterior crural muscles was performed with simultaneous M‐wave recording from the TA muscle. To measure PTP, baseline twitch torque production was measured using a 0.1‐ms electrical stimulus pulse. Ten seconds later, muscles were stimulated using 0.1‐ms pulses at 100 Hz for 1 s to produce a prolonged, isometric tetanic contraction. Starting 2 s later, two post‐tetanic twitches were elicited with 2 s between the two. Changes in twitch torque (i.e., PTP) and M‐wave amplitude were calculated as percent increases in twitch torque and the corresponding M‐wave from baseline to the highest values following tetanic stimulation. All data were analyzed using paired t‐tests and are reported as means ± SE.ResultsTwitch torque at baseline was 0.45 ± 0.07 mN·m and represented the unpotentiated twitch. Following the tetanic stimulation, twitch torque increased by 34.0 ± 7.3% to 0.60 ± 0.07 mN·m (p=0.01). However, no change was detected in twitch M‐wave amplitude from before to after the tetanic stimulation (0.37 ± 0.03 to 0.39 ± 0.04 mV, p=0.48).ConclusionOn the basis of the disproportionate increase in twitch torque (34%) compared to the corresponding M‐wave amplitude increase (5%) after tetanic stimulation (p=0.02), we suggest that the PTP was not due to an increase in fiber excitability. Instead, it is more likely that PTP was attributable to an enhancement at or distal to SR calcium release such as phosphorylation of myosin regulatory light chain, which is consistent with previously reported mechanisms underlying PTP.Support or Funding InformationSupported by NIH grants R01‐AG031743 and T32‐AR007612, and Metropolitan State University Professional Development Grant.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Wire Electrodes Embedded in Artificial Conduit for Long-term Monitoring of the Peripheral Nerve Signal.

Massive efforts to develop neural interfaces have been made for controlling prosthetic limbs according to the will of the patient, with the ultimate goal being long-term implantation. One of the major struggles is that the electrode’s performance degrades over time due to scar formation. Herein, we have developed peripheral nerve electrodes with a cone-shaped flexible artificial conduit capable of protecting wire electrodes from scar formation. The wire electrodes, which are composed of biocompatible alloy materials, were embedded in the conduit where the inside was filled with collagen to allow the damaged nerves to regenerate into the conduit and interface with the wire electrodes. After implanting the wire electrodes into the sciatic nerve of a rat, we successfully recorded the peripheral neural signals while providing mechanical stimulation. Remarkably, we observed the external stimuli-induced nerve signals at 19 weeks after implantation. This is possibly due to axon regeneration inside our platform. To verify the tissue response of our electrodes to the sciatic nerve, we performed immunohistochemistry (IHC) and observed axon regeneration without scar tissue forming inside the conduit. Thus, our strategy has proven that our neural interface can play a significant role in the long-term monitoring of the peripheral nerve signal.

The neurosurgical treatment of craniofacial pain syndromes: current surgical indications and techniques.

Craniofacial pain syndromes are comprised of multiple pathological entities resulting in pain referred to the scalp, face, or deeper cranial structures. In a small subset of patients affected by those syndromes, pharmacological and physical therapies fail in alleviating pain. In some of those refractory patients surgical procedures aimed at relieving pain are indicated and have been adopted with variable results and safety profiles. In this review, the authors describe craniofacial pain syndromes that most commonly fail to respond to pharmacological therapies and may be amenable to tailored surgical procedures. In particular, trigeminal, glossopharyngeal, and occipital neuralgias are considered, as well as some primary headache syndromes such as cluster headache, short unilateral neuralgiform headache with conjunctival injection and tearing/short unilateral neuralgiform headache with autonomic symptoms, and migraine. Surgical techniques, including the implantation of deep brain or peripheral nerve electrodes with subsequent chronic stimulation, microvascular decompression of neurovascular conflicts, and percutaneous lesioning of neural structures are described. Finally, surgical indications, outcomes, and safety of these procedures are presented.

Physiological parallels with perception

Signal detection theory (SDT) lends itself to comparison among perceptual and physiological results in humans and other animals. In physiological recordings, trial-by-trial distributions of single-unit spike counts or of event-related-potentials typically yield non-normal distributions, calling for non-parametric tests. An empirical receiver operating characteristic (ROC) curve can compare distributions of physiological measures between pairs of stimulus conditions. The area under the ROC curve is a non-parametric measure of sensitivity, yielding the proportion correct and, thence, the sensitivity index, d’. The d’ cumulated over a succession of the increasing values of a stimulus parameter provides a measure of the growth of response over that parameter range. I will present examples from several ongoing projects including: (1) studies of activation of the central auditory pathway by cochlear implants and by a penetrating auditory nerve electrode, with single-unit recordings from the inferior colliculus; (2) comparisons of spatial stream segregation among 2-alternative forced choice in humans, hold-response measures in cats, and cortical single-unit recording in cats; and (3) studies of frequency sensitivity using the auditory change complex and masked onset responses. In general, these techniques derived from SDT yield a satisfying agreement among perceptual measures and their physiological underpinnings.

Accelerated Recovery of DC Blocking Using Repolarization.

Direct current (DC) can be applied to a nerve to generate a complete nerve block. However, using conventional platinum electrodes, reactions occur at the nerve interface causing damage to the nerve. The electrode can be separated from the nerve using a biocompatible, ionically conducting medium, which isolates the damaging reactions in a vessel away from the nerve. This electrode has previously been referred to as the Separated Interface Nerve Electrode (SINE). Recent experiments have shown that when a complete block is applied, for a prolonged period of time, there is a delay in the recovery of the response. For many applications it would be advantageous to have instantaneous recovery. To achieve this, the SINE electrode was used to provide a complete, instantaneous nerve block at the block threshold for 10 minutes and then the current was reversed for selected time periods to determine if instantaneous recovery could be achieved. Depending on the length of time of the repolarization, the amount of time for recovery can be reduced by as much as 50%.

AT1 receptors in the subfornical organ modulate arterial pressure and the baroreflex in two-kidney, one-clip hypertensive rats.

The subfornical organ (SFO), a forebrain circumventricular organ that lies outside the blood-brain barrier, has been implicated in arterial pressure and baroreflex responses to angiotensin II (ANG II). We tested whether pharmacological inhibition or selective silencing of SFO ANG II type 1 receptors (AT1R) of two-kidney, one-clip rats with elevated plasma ANG II decreases resting arterial pressure and renal sympathetic nerve activity (RSNA) and/or modulates arterial baroreflex responses of heart rate (HR) and RSNA. Male Sprague-Dawley rats underwent renal artery clipping [2-kidney, 1-clip (2K,1C)] or sham clipping (sham). After 6 wk, conscious rats instrumented with vascular catheters, renal nerve electrodes, and a cannula directed to the SFO were studied. In another set of experiments, rats were instrumented with hemodynamic and nerve radio transmitters and injected with scrambled RNA or silencing RNA targeted against AT1R. Mean arterial pressure (MAP) was significantly higher in 2K,1C rats. Acute SFO injection with the AT1R inhibitor losartan did not change MAP in sham or 2K,1C rats. Baroreflex curves of HR and RSNA were shifted rightward in 2K,1C rats. Losartan exerted no effect. SFO AT1R knockdown did not influence MAP in sham rats but decreased MAP in 2K,1C rats, despite no change in plasma ANG II or resting RSNA. AT1R knockdown prevented the reduction in maximum gain and slope of baroreflex responses of HR and RSNA; the reduced RSNA response to baroreceptor unloading was partially restored in 2K,1C rats. These findings show that AT1R activation within the SFO contributes to hypertension and baroreflex dysfunction in 2K,1C rats and highlight the temporal requirement for reversal of these effects.

Handheld Nerve Electrode Insertion Tool

This paper introduces a new type of miniature device to insert an intrafascicular electrode into a peripheral nervous system that is covered with tough tissue membranes. The developed device is called nerve electrode insertion tool (NEIT) and consists of a nerve holder unit and an electrode insertion unit. Users can easily adjust the insertion position and direction of nerve electrodes while freely manipulating this compact handheld device. This paper introduces the form, configuration, and underlying mechanisms of the device and related surgical procedure. Utility tests using elastomer-made nerve models show that the electrode insertion time and position accuracy, respectively, improve from 72.1 to 4.17 s and 0.37 to 0.11 mm when employing the NEIT. Animal experiment results show that multishank planar electrodes (2 × 2 mm2) are successfully implanted into sciatic nerves of six rats. Treadmill tests and histological analysis present the neural functions of all the treated nerves are successfully recovered after three weeks. We expect the NEIT to be employed for other kinds of nerve electrodes and simplify the surgical process in neural engineering research.

Cochlear implantation in far-advanced otosclerosis: hearing results and complications.

SUMMARYSevere forms of otosclerosis known as far-advanced otosclerosis (FAO) can lead to severe to profound sensorineural hearing loss and can justify cochlear implantation. Because of the pathophysiology of otosclerosis, patients implanted for FAO may experience an increased rate of complications, such as facial nerve stimulation or electrode dislocation, and may have poorer hearing outcomes than expected. This retrospective study aimed to compare cochlear implantation hearing outcomes, surgical difficulties and complications in FAO patients versus non-FAO patients. Moreover, we evaluated whether high resolution computed tomography (CT scan) findings were predictive of perioperative problems, complications and hearing outcomes. FAO patients were diagnosed based on medical history, examination and CT scan. Thirty-five ears from FAO patients were compared to 38 control ears. Audiometric results were assessed at least 12 months after implantation by pure tone average, speech reception threshold, monosyllabic and disyllabic word recognition score (WRS) and Central Institute for the Deaf (CID) sentences test. Complications and surgical difficulties were compiled. CT scan findings were categorised within 3 grades of otosclerotic extension. No significant difference was found between FAO and non-FAO hearing outcomes, except that monosyllabic WRS were lower for FAO patients, especially those who underwent previous stapedotomy. Facial nerve symptomatology occurred in 8.6% of FAO patients; among these, one required explantation-reimplantation surgery. 86% of FAO implanted patients had retrofenestral extension on CT. These were associated with poorer disyllabic WRS (51% vs 68%, p < 0.05) than those with only fenestral involvement. Although not significant, high grade of severity on CT tended to be associated with surgical difficulties and complications. Cochlear implantation in FAO patients is an effective treatment technique. Though the overall complication rate is low, it tends to be higher in cases of severe extension on CT. Patient counselling should be adjusted accordingly.

Recovering Motor Activation with Chronic Peripheral Nerve Computer Interface

Interfaces with the peripheral nerve provide the ability to extract motor activation and restore sensation to amputee patients. The ability to chronically extract motor activations from the peripheral nervous system remains an unsolved problem. In this study, chronic recordings with the Flat Interface Nerve Electrode (FINE) are employed to recover the activation levels of innervated muscles. The FINEs were implanted on the sciatic nerves of canines, and neural recordings were obtained as the animal walked on a treadmill. During these trials, electromyograms (EMG) from the surrounding hamstring muscles were simultaneously recorded and the neural recordings are shown to be free of interference or crosstalk from these muscles. Using a novel Bayesian algorithm, the signals from individual fascicles were recovered and then compared to the corresponding target EMG of the lower limb. High correlation coefficients (0.84 ± 0.07 and 0.61 ± 0.12) between the extracted tibial fascicle/medial gastrocnemius and peroneal fascicle/tibialis anterior muscle were obtained. Analysis calculating the information transfer rate (ITR) from the muscle to the motor predictions yielded approximately 5 and 1 bit per second (bps) for the two sources. This method can predict motor signals from neural recordings and could be used to drive a prosthesis by interfacing with residual nerves.

Noninvasive, tube-based, continuous vagal nerve monitoring using the laryngeal adductor reflex: Feasibility study of 134 nerves at risk.

Continuous vagal intraoperative neuromonitoring (IONM) currently requires placement of a vagal nerve electrode. Herein, we present data from 100 patients (134 nerves-at-risk) monitored continuously during neck endocrine surgeries using a noninvasive, new methodology that solely utilizes endotracheal tube electrodes to simultaneously stimulate laryngeal mucosa and record a laryngeal adductor reflex continuous IONM (LAR-C-IONM) response. The laryngeal adductor reflex (LAR) was elicited by electrical laryngeal mucosal stimulation on the side contralateral to the operative field using endotracheal tube electrodes. All patients completed preoperative and postoperative laryngeal and voice examinations. One hundred patients (134 nerves-at-risk) were included. Significantly more nerves-at-risk with an LAR opening to closing amplitude decrement >60% or with absolute closing amplitude <100 μV had postoperative vocal fold paralysis (P < .001). The LAR-C-IONM was highly sensitive to recurrent laryngeal nerve (RLN) stretch or compression. The LAR-C-IONM is a promising new way to perform continuous vagal monitoring that requires no equipment other than an electromyography (EMG) endotracheal tube and is undergoing further, large-scale evaluation.

Carbon Nanotube‐Silicone Rubber on Active Thin‐Film Implants

To improve interfacing with neurites, flexible electrode materials consisting of carbon nanotubes (CNTs) and silicone rubber are investigated. Here, the authors present a method for defined application of CNT‐silicone rubber on electrode surfaces. However, for low impedance as well as intimate contact between nerve cells and electrodes, additional reduction of the silicone rubber layer via etching at the interface is necessary. This requires protection of the electrodes using photoresist. The etching methods are optimized for application on ready‐to‐use electrode arrays and characterized using impedance spectroscopy and scanning electron microscopy.

Update on Peripheral Nerve Electrodes for Closed-Loop Neuroprosthetics.

In this paper various types of electrodes for stimulation and recording activity of peripheral nerves for the control of neuroprosthetic limbs are reviewed. First, an overview of interface devices for (feedback-) controlled movement of a prosthetic device is given, after which the focus is on peripheral nervous system (PNS) electrodes. Important electrode properties, i.e., longevity and spatial resolution, are defined based upon the usability for neuroprostheses. The cuff electrode, longitudinal intrafascicular electrodes (LIFE), transverse intrafascicular multichannel electrode (TIME), Utah slanted electrode array (USEA), and the regenerative electrode are discussed and assessed on their longevity and spatial resolution. The cuff electrode seems to be a promising electrode for the control of neuroprostheses in the near future, because it shows the best longevity and good spatial resolution and it has been used on human subjects in multiple studies. The other electrodes may be promising in the future, but further research on their longevity and spatial resolution is needed. A more quantitatively uniform study protocol used for all electrodes would allow for a proper comparison of recording and stimulation performance. For example, the discussed electrodes could be compared in a large in vivo study, using one uniform comparison protocol.

T155. Brain reactions following the use of robotic hand prosthesis in human amputees

Introduction The amputation of a hand is followed by a cascade of plastic changes into the motor and somatosensory pathways in the CNS; such changes are probably contributing to the Phantom limb syndrome (PLS), a distressing situation affecting the majority of amputees, and could be modulated providing sensory input to the stump or amputation zone. Very few information is reported in literature explaining how plastic changes evolve during the use of prosthesis, particularly the new sensorized hand prosthesis, which provide the use of intraneural electrodes able to restore a “natural” somatosensory feedback. In this line, we performed a clinical study with four trans-radial amputees, who received an implant of four transversal intrafascicular electrodes in median and ulnar nerves controlling hand prosthesis, with the aim to investigate cortical changes occurring during trainings of different durations (4–24 weeks). Methods All patients underwent to a multimodal evaluation performed before and after the use of neural-interfaced hand prosthesis, including TMS examination with motor maps production, SEPs recording, EEG source analysis, connectivity analysis and fMRI. Standard pain questionnaires (VAS, McGill and PPI scores) were used to assess the course of PLS. Results After the interventions, the following findings were observed: – TMS motor maps showed a reduction and a partial reversal of an initial inter-hemispheric asymmetry (because of an enlargement of the excitable area on the hemisphere contralateral to the stump); – SEPs based on N20 component showed a modification of the cortical topography in the central-parietal areas contralateral to the amputation site; – EEG source analysis showed a widespread reduction of delta activity and a significant increase of alpha activity in the central-parietal areas in both hemispheres; – According to the graph theory, the analysis of the sensory-motor network showed in both hemispheres a significant increase of the Characteristic Path Length and a significant decrease of Small World Index in the alpha band; – fMRI showed a decrease in activation of supplementary and premotor areas with a prominent and more selective activation of the M1 area; – All the patients experiencend a decrease of PLP. Conclusion Our data provides a direct and unique evidence of brain plastic changes following the restoration of somatosensory feedback from a missing limb. We observed changes in the cortical organization towards a more physiological state in all the four patients during an extensive use of robotic hand. We associated these brain reactions to a decrease in pain intensity and an improvement of prosthesis control performance. The prosthetic system could induce reduction in aberrant plasticity and promote ‘good’ “training-induced” plasticity. Neurophysiological and neuroimaging analysis could be seen as potential biomarker of the level of CNS reorganization and therefore used as parameter of the effectiveness achieved by the prosthetic device and its interfaces.

Flexible multichannel vagus nerve electrode for stimulation and recording for heart failure treatment

Vagus nerve stimulation is an emerging bioelectronic medicine to modulate cardiac function, as the nerve provides parasympathetic innervation to the heart. In this study, we developed a polyimide based 2D cuff electrode to wrap around on the vagus nerve. Thanks to the tiny size and bendable protruding structure of the contact tips of the device, the electrode sites are able to flexibly bend to touch the nerve, selectively record and stimulate the vagus nerve. Gold, platinum and platinum black materials were chosen to compose the electrodes for nerve stimulation and recording, respectively. Since the platinum black has ~30 times larger charge delivery capacity (CDC) than gold, Pt black electrode is used for nerve stimulation. The electrochemical impedance spectroscopy and cyclic voltammetry measurement of the three materials were conducted in vitro, revealing the results of 405 kΩ, 41 kΩ, 10.5 kΩ, @1 kHz and 0.81 mC/cm2, 4.26 mC/cm2, 25.5 mC/cm2, respectively (n = 3). The cuff electrodes were implanted into the right-sided vagus nerve of rats for in vivo experiment. Biphasic current configuration was implemented for nerve stimulation with frequency of 10 Hz, pulse during of 300 μs and various currents stimulus. The result shows the heart beat frequency drops up to 36% during the stimulation and was able to return the regular frequency as stimulation was removed. Subsequently, the vagus nerve signals were recorded with the four channel cuff electrodes. The magnitude of the compound nerve action potentials (CNAPs) is ~10 μV and the signal to noise ratio (SNR) is ~20.

On the use of Parylene C polymer as substrate for peripheral nerve electrodes

Parylene C is a highly flexible polymer used in several biomedical implants. Since previous studies have reported valuable biocompatible and manufacturing characteristics for brain and intraneural implants, we tested its suitability as a substrate for peripheral nerve electrodes. We evaluated 1-year-aged in vitro samples, where no chemical differences were observed and only a slight deviation on Young’s modulus was found. The foreign body reaction (FBR) to longitudinal Parylene C devices implanted in the rat sciatic nerve for 8 months was characterized. After 2 weeks, a capsule was formed around the device, which continued increasing up to 16 and 32 weeks. Histological analyses revealed two cell types implicated in the FBR: macrophages, in contact with the device, and fibroblasts, localized in the outermost zone after 8 weeks. Molecular analysis of implanted nerves comparing Parylene C and polyimide devices revealed a peak of inflammatory cytokines after 1 day of implant, returning to low levels thereafter. Only an increase of CCL2 and CCL3 was found at chronic time-points for both materials. Although no molecular differences in the FBR to both polymers were found, the thick tissue capsule formed around Parylene C puts some concern on its use as a scaffold for intraneural electrodes.

Evaluation of high-density, multi-contact nerve cuffs for activation of grasp muscles in monkeys

Objective. The objective of this work was to evaluate whether nerve cuffs can selectively activate hand muscles for functional electrical stimulation (FES). FES typically involves identifying and implanting electrodes in many individual muscles, but nerve cuffs only require implantation at a single site around the nerve. This method is surgically more attractive. Nerve cuffs may also more effectively stimulate intrinsic hand muscles, which are difficult to implant and stimulate without spillover to adjacent muscles. Approach. To evaluate its ability to selectively activate muscles, we implanted and tested the flat interface nerve electrode (FINE), which is designed to selectively stimulate peripheral nerves that innervate multiple muscles (Tyler and Durand 2002 IEEE Trans. Neural Syst. Rehabil. Eng. 10 294–303). We implanted FINEs on the nerves and bipolar intramuscular wires for recording compound muscle action potentials (CMAPs) from up to 20 muscles in each arm of six monkeys. We then collected recruitment curves while the animals were anesthetized. Main result. A single FINE implanted on an upper extremity nerve in the monkey can selectively activate muscles or small groups of muscles to produce multiple, independent hand functions. Significance. FINE cuffs can serve as a viable supplement to intramuscular electrodes in FES systems, where they can better activate intrinsic and extrinsic muscles with lower currents and less extensive surgery.

Rapid prototyping of flexible intrafascicular electrode arrays by picosecond laser structuring

Objective. Interfacing the peripheral nervous system can be performed with a large variety of electrode arrays. However, stimulating and recording a nerve while having a reasonable amount of channels limits the number of available systems. Translational research towards human clinical trial requires device safety and biocompatibility but would benefit from design flexibility in the development process to individualize probes. Approach. We selected established medical grade implant materials like precious metals and Parylene C to develop a rapid prototyping process for novel intrafascicular electrode arrays using a picosecond laser structuring. A design for a rodent animal model was developed in conjunction with an intrafascicular implantation strategy. Electrode characterization and optimization was performed first in saline solution in vitro before performance and biocompatibility were validated in sciatic nerves of rats in chronic implantation. Main results. The novel fabrication process proved to be suitable for prototyping and building intrafascicular electrode arrays. Electrochemical properties of the electrode sites were enhanced and tested for long-term stability. Chronic implantation in the sciatic nerve of rats showed good biocompatibility, selectivity and stable stimulation thresholds. Significance. Established medical grade materials can be used for intrafascicular nerve electrode arrays when laser structuring defines structure size in the micro-scale. Design flexibility reduces re-design cycle time and material certificates are beneficial support for safety studies on the way to clinical trials.

Preparation of mechanically enhanced hydrogel scaffolds by incorporating interfacial polymer nanorods for nerve electrode application

Hydrogel-based integral nerve electrodes have been studied as an effective implant strategy for recovery after a spinal cord injury (SCI). However, a weak physical connection between the hydrogel and nerve electrode can lead to implant failure. In this study, we introduce poly(L-lactic acid) (PLA) nanorods (PLANRs) as a new approach to improve the physical property, i.e. stability of agarose hydrogel-based integrated neuro-electrodes. The hydrogels were characterized by scanning electron microscope (SEM), rheometry, and tensile test machine. Thus, the hydrogels containing PLANRs displayed high mechanical properties. These interesting findings suggest that PLANRs enhance the mechanical properties of integral nerve electrode hydrogels making them useful materials in neural tissue engineering.

Electroacupuntura y neuromodulación en la médula espinal: implicaciones en el dolor neuropático

Neuromodulation by electrical stimulation of the nervous system constitutes a novel therapeutic strategy in the treatment of pain. It has been shown that electroacupuncture (EA) may activate afferent fibres in a similar manner to direct electrical stimulation of peripheral nerves. The difference is that EA is a percutaneous stimulation using needles, and is less invasive than the surgery required for the implantation of electrodes in the peripheral nerves. In neuropathic pain models, it has been shown that EA modulates multiple interconnected systems in the body. At the level of the spinal cord, EA activates serotonergic, adrenergic, cholinergic, and opioid pathways, as well as presynaptic mechanisms associated with primary afferent depolarisation. It has also been shown that EA effects extend to neuroglia. The characterisation of EA parameters as intensity, frequency, and duration of pulses is essential for the induction of neuromodulation of synaptic transmission at the spinal cord level, and consequently, it could be used for the development of optimal therapeutic actions in pain treatment.

Fascicular nerve stimulation and recording using a novel double-aisle regenerative electrode

Objective. As artificial prostheses become more refined, they are most often used as a therapeutic option for hand amputation. By contrast to extra- or intraneural interfaces, regenerative nerve electrodes are designed to enable electrical interfaces with regrowing axonal bundles of injured nerves, aiming to achieve high selectivity for recording and stimulation. However, most of the developed designs pose an obstacle to the regrowth mechanisms due to low transparency and cause impairment to the nerve regeneration. Approach. Here we present the double-aisle electrode, a new type of highly transparent, non-obstructive regenerative electrode. Using a double-side thin-film polyimide planar multi-contact electrode, two nerve fascicles can regenerate without physical impairment through two electrically isolated aisles. Main results. We show that this electrode can be used to selectively record and stimulate fascicles, acutely as well as chronically, and allow regeneration in nerve gaps of several millimeters without impairment. Significance. This multi-aisle regenerative electrode may be suitable for neuroprosthetic applications, such as prostheses, for the restoration of hand function after amputation or severe nerve injuries.