scholarly journals Viral-mediated optogenetic stimulation of peripheral motor nerves in non-human primates

2018 ◽  
Author(s):  
Jordan J. Williams ◽  
Alan M. Watson ◽  
Alberto L. Vazquez ◽  
Andrew B. Schwartz
Keyword(s):  
Gene Therapy ◽  
Post Injection ◽  
Optical Stimulation ◽  
Stimulus Pulse ◽  
Opsin Expression ◽  
Optogenetic Stimulation ◽  
Cord Injury ◽  
Motor Nerves ◽  
Peripheral Motor ◽  
Stimulation Of

AbstractObjectiveReanimation of muscles paralyzed by disease states such as spinal cord injury remains a much sought after therapeutic goal of neuroprosthetic research. Optogenetic stimulation of peripheral motor nerves expressing light-sensitive opsins is a promising approach to muscle reanimation that may overcome several drawbacks of traditional methods such as functional electrical stimulation (FES). However, the utility of these methods has only been demonstrated in rodents to date, while translation to clinical practice will likely first require demonstration and refinement of these gene therapy techniques in non-human primates.ApproachThree rhesus macaques were injected intramuscularly with either one or both of two optogenetic constructs (AAV6-hSyn-ChR2-eYFP and/or AAV6-hSyn-Chronos-eYFP) to transduce opsin expression in the corresponding nerves. Neuromuscular junctions were targeted for virus delivery using an electrical stimulating injection technique. Functional opsin expression was periodically evaluated up to 13 weeks post-injection by optically stimulating targeted nerves with a 472 nm fiber-coupled laser while recording electromyographic (EMG) responses.Main ResultsOne monkey demonstrated functional expression of ChR2 at 8 weeks post-injection in each of two injected muscles, while the second monkey briefly exhibited contractions coupled to optical stimulation in a muscle injected with the Chronos construct at 10 weeks. A third monkey injected only in one muscle with the ChR2 construct showed strong optically coupled contractions at 5 ½ weeks which then disappeared by 9 weeks. EMG responses to optical stimulation of ChR2-transduced nerves demonstrated graded recruitment relative to both stimulus pulse-width and light intensity, and were able to track stimulus trains up to 16 Hz. In addition, the EMG response to prolonged stimulation showed delayed fatigue over several minutes.SignificanceThese results demonstrate the feasibility of viral transduction of peripheral motor nerves for functional optical stimulation of motor activity in non-human primates, a variable timeline of opsin expression in a primate model closer to humans, and fundamental EMG response characteristics to optical nerve stimulation. Subsequently, they represent an important step in translating these optogenetic techniques as a clinically viable gene therapy.

scholarly journals Viral-Mediated Optogenetic Stimulation of Peripheral Motor Nerves in Non-human Primates

2019 ◽  
Vol 13 ◽  
Author(s):  
Jordan J. Williams ◽  
Alan M. Watson ◽  
Alberto L. Vazquez ◽  
Andrew B. Schwartz
Keyword(s):  
Optogenetic Stimulation ◽  
Motor Nerves ◽  
Peripheral Motor ◽  
Stimulation Of

scholarly journals Calcium Imaging Reveals Host-Graft Synaptic Network Formation in Spinal Cord Injury

2019 ◽  
Author(s):  
S Ceto ◽  
KJ Sekiguchi ◽  
Y Takashima ◽  
A Nimmerjahn ◽  
MH Tuszynski
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Calcium Imaging ◽  
Progenitor Cell ◽  
Neural Progenitor Cell ◽  
Neural Progenitor ◽  
Optogenetic Stimulation ◽  
Cord Injury ◽  
Stimulation Of

SummaryNeural stem/progenitor cell grafts integrate into sites of spinal cord injury (SCI) and form anatomical and electrophysiological neuronal relays across lesions. To determine how grafts become synaptically organized and connect with host systems, we performed calcium imaging of neural progenitor cell grafts within sites of SCI, using both in vivo imaging and spinal cord slices. Stem cell grafts organize into localized synaptic networks that are spontaneously active. Following optogenetic stimulation of host corticospinal tract axons regenerating into grafts, distinct and segregated neuronal networks respond throughout the graft. Moreover, optogenetic stimulation of graft axons extending out from the lesion into the denervated spinal cord also trigger responses in local host neuronal networks. In vivo imaging reveals that behavioral stimulation of host elicits focal synaptic responses within grafts. Thus, remarkably, neural progenitor cell grafts form functional synaptic subnetworks in patterns paralleling the normal spinal cord.

scholarly journals Freely Behaving Mice Can Brake and Turn During Optogenetic Stimulation of the Mesencephalic Locomotor Region

2021 ◽  
Vol 15 ◽  
Author(s):  
Cornelis Immanuel van der Zouwen ◽  
Joël Boutin ◽  
Maxime Fougère ◽  
Aurélie Flaive ◽  
Mélanie Vivancos ◽  
...  
Keyword(s):  
Patch Clamp ◽  
Open Field ◽  
Environmental Cues ◽  
Dependent Manner ◽  
Mesencephalic Locomotor Region ◽  
Optogenetic Stimulation ◽  
Cuneiform Nucleus ◽  
Cord Injury ◽  
Freely Behaving ◽  
Stimulation Of

A key function of the mesencephalic locomotor region (MLR) is to control the speed of forward symmetrical locomotor movements. However, the ability of freely moving mammals to integrate environmental cues to brake and turn during MLR stimulation is poorly documented. Here, we investigated whether freely behaving mice could brake or turn, based on environmental cues during MLR stimulation. We photostimulated the cuneiform nucleus (part of the MLR) in mice expressing channelrhodopsin in Vglut2-positive neurons in a Cre-dependent manner (Vglut2-ChR2-EYFP) using optogenetics. We detected locomotor movements using deep learning. We used patch-clamp recordings to validate the functional expression of channelrhodopsin and neuroanatomy to visualize the stimulation sites. In the linear corridor, gait diagram and limb kinematics were similar during spontaneous and optogenetic-evoked locomotion. In the open-field arena, optogenetic stimulation of the MLR evoked locomotion, and increasing laser power increased locomotor speed. Mice could brake and make sharp turns (~90°) when approaching a corner during MLR stimulation in the open-field arena. The speed during the turn was scaled with the speed before the turn, and with the turn angle. Patch-clamp recordings in Vglut2-ChR2-EYFP mice show that blue light evoked short-latency spiking in MLR neurons. Our results strengthen the idea that different brainstem neurons convey braking/turning and MLR speed commands in mammals. Our study also shows that Vglut2-positive neurons of the cuneiform nucleus are a relevant target to increase locomotor activity without impeding the ability to brake and turn when approaching obstacles, thus ensuring smooth and adaptable navigation. Our observations may have clinical relevance since cuneiform nucleus stimulation is increasingly considered to improve locomotion function in pathological states such as Parkinson’s disease, spinal cord injury, or stroke.

Emerging approaches for restoration of hearing and vision

2020 ◽  
Author(s):  
Sonja Kleinlogel ◽  
Christian Vogl ◽  
Marcus Jeschke ◽  
Jakob Neef ◽  
Tobias Moser
Keyword(s):  
Gene Therapy ◽  
Hearing Aids ◽  
Sensory Information ◽  
Gene Replacement ◽  
Therapeutic Approaches ◽  
Optogenetic Stimulation ◽  
Cellular Specificity ◽  
Socioeconomic Burden ◽  
Comprehensive Reference

Impairments of vision and hearing are highly prevalent conditions limiting the quality of life and presenting a major socioeconomic burden. For long, retinal and cochlear disorders have remained intractable for causal therapies, with sensory rehabilitation limited to glasses, hearing aids, and electrical cochlear or retinal implants. Recently, the application of gene therapy and optogenetics to eye and ear has generated hope for a fundamental improvement of vision and hearing restoration. To date, one gene therapy for the restoration of vision has been approved and undergoing clinical trials will broaden its application including gene replacement, genome editing, and regenerative approaches. Moreover, optogenetics, i.e. controlling the activity of cells by light, offers a more general alternative strategy. Over little more than a decade, optogenetic approaches have been developed and applied to better understand the function of biological systems, while protein engineers have identified and designed new opsin variants with desired physiological features. Considering potential clinical applications of optogenetics, the spotlight is on the sensory systems. Multiple efforts have been undertaken to restore lost or hampered function in eye and ear. Optogenetic stimulation promises to overcome fundamental shortcomings of electrical stimulation, namely poor spatial resolution and cellular specificity, and accordingly to deliver more detailed sensory information. This review aims at providing a comprehensive reference on current gene therapeutic and optogenetic research relevant to the restoration of hearing and vision. We will introduce gene-therapeutic approaches and discuss the biotechnological and optoelectronic aspects of optogenetic hearing and vision restoration.

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