Combining Optogenetic Stimulation and Motor Training Improves Functional Recovery and Perilesional Cortical Activity

Background. An ischemic stroke is followed by the remapping of motor representation and extensive changes in cortical excitability involving both hemispheres. Although stimulation of the ipsilesional motor cortex, especially when paired with motor training, facilitates plasticity and functional restoration, the remapping of motor representation of the single and combined treatments is largely unexplored. Objective. We investigated if spatio-temporal features of motor-related cortical activity and the new motor representations are related to the rehabilitative treatment or if they can be specifically associated to functional recovery. Methods. We designed a novel rehabilitative treatment that combines neuro-plasticizing intervention with motor training. In detail, optogenetic stimulation of peri-infarct excitatory neurons expressing Channelrhodopsin 2 was associated with daily motor training on a robotic device. The effectiveness of the combined therapy was compared with spontaneous recovery and with the single treatments (ie optogenetic stimulation or motor training). Results. We found that the extension and localization of the new motor representations are specific to the treatment, where most treatments promote segregation of the motor representation to the peri-infarct region. Interestingly, only the combined therapy promotes both the recovery of forelimb functionality and the rescue of spatio-temporal features of motor-related activity. Functional recovery results from a new excitatory/inhibitory balance between hemispheres as revealed by the augmented motor response flanked by the increased expression of parvalbumin positive neurons in the peri-infarct area. Conclusions. Our findings highlight that functional recovery and restoration of motor-related neuronal activity are not necessarily coupled during post-stroke recovery. Indeed the reestablishment of cortical activation features of calcium transient is distinctive of the most effective therapeutic approach, the combined therapy.

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Optogenetic Stimulation Reduces Neuronal Nitric Oxide Synthase Expression After Stroke

Neurosurgery ◽

10.1093/neuros/nyz310_173 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Author(s):

Arjun Vivek Pendharkar ◽

Daniel L Smerin ◽

Lorenzo Gonzales ◽

Eric Wang ◽

Sabrina L Levy ◽

...

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Motor Cortex ◽

Functional Recovery ◽

Neuronal Nitric Oxide Synthase ◽

Optogenetic Stimulation ◽

Oxide Synthase ◽

Nnos Expression ◽

Stimulation Of ◽

Nnos Inhibition

Abstract INTRODUCTION Poststroke optogenetic stimulation has been shown to enhance neurovascular coupling and functional recovery. Neuronal nitric oxide synthase (nNOS) has been implicated as a key regulator of neurovascular response in acute stroke but its role in subacute recovery remains unclear. Here we investigate nNOS expression in stroke mice undergoing optogenetic stimulation of the contralesional lateral cerebellar nucleus (cLCN). We also examine the effects of nNOS inhibition on functional recovery using a pharmacological inhibitor targeting nNOS. METHODS Transgenic Thy1-ChR2-YFP male mice (10-12 wk) were used. Stereotaxic surgery was performed to implant a fiber cannula in the cLCN and animals underwent intraluminal middle cerebral artery suture occlusion (30 min). Optogenetic stimulation began at poststroke (PD) day 5 and continued until PD14. Sensorimotor tests were used to assess behavioral recovery at PD4, 7, 10, and 14. At PD15, primary motor cortex from both ipsi- and contralesional motor cortex (iM1, cM1) were dissected. nNOS mRNA and protein levels were examined using quantitative polymerase chain reaction and western blot. In another set of studies, nNOS inhibitor ARL 17477 dihydrochloride (10 mg/kg, intraperitoneally) was administered daily between PD5-14 and functional recovery was evaluated using sensorimotor tests. RESULTS cLCN stimulated stroke mice demonstrated significant improvement in speed (cm/s) on the rotating beam task at PD10 and 14 day (P < .05, P < .001 respectively). nNOS mRNA and protein expression was significantly and selectively decreased in cM1 of cLCN stimulated mice (P < .05). The reduced nNOS expression in cM1 was negatively correlated with improved recovery (R2 = −0.839, Pearson P = .009). nNOS inhibitor-treated stroke mice exhibited a significant functional improvement in speed at PD10, when compared to stroke mice receiving vehicle (saline) (P < .05). CONCLUSION Our results suggest that nNOS may play a maladaptive role in poststroke recovery. Optogenetic stimulation of cLCN and systemic nNOS inhibition produce functional benefits after stroke.

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Reversible Ca Gradients between the Subplasmalemma and Cytosol Differentially Activate Ca-dependent Cl Currents

The Journal of General Physiology ◽

10.1085/jgp.113.2.249 ◽

1999 ◽

Vol 113 (2) ◽

pp. 249-266 ◽

Cited By ~ 33

Author(s):

Khaled Machaca ◽

H. Criss Hartzell

Keyword(s):

Endoplasmic Reticulum ◽

Plasma Membrane ◽

Confocal Microscopy ◽

Driving Force ◽

Xenopus Oocytes ◽

Biophysical Properties ◽

Temporal Features ◽

Cl Channels ◽

Spatio Temporal ◽

Stimulation Of

Xenopus oocytes express several different Ca-activated Cl currents that have different waveforms and biophysical properties. We compared the stimulation of Ca-activated Cl currents measured by two-microelectrode voltage clamp with the Ca transients measured in the same cell by confocal microscopy and Ca-sensitive fluorophores. The purpose was to determine how the amplitude and/or spatio-temporal features of the Ca signal might explain how these different Cl currents were activated by Ca. Because Ca release from stores was voltage independent, whereas Ca influx depended upon the electrochemical driving force, we were able to separately assess the contribution of Ca from these two sources. We were surprised to find that Ca signals measured with a cytosolic Ca-sensitive dye, dextran-conjugated Ca-green-1, correlated poorly with Cl currents. This suggested that Cl channels located at the plasma membrane and the Ca-sensitive dye located in the bulk cytosol were sensing different [Ca]. This was true despite Ca measurement in a confocal slice very close to the plasma membrane. In contrast, a membrane-targeted Ca-sensitive dye (Ca-green-C18) reported a Ca signal that correlated much more closely with the Cl currents. We hypothesize that very local, transient, reversible Ca gradients develop between the subplasmalemmal space and the bulk cytosol. [Ca] is higher near the plasma membrane when Ca is provided by Ca influx, whereas the gradient is reversed when Ca is released from stores, because Ca efflux across the plasma membrane is faster than diffusion of Ca from the bulk cytosol to the subplasmalemmal space. Because dissipation of the gradients is accelerated by inhibition of Ca sequestration into the endoplasmic reticulum with thapsigargin, we conclude that [Ca] in the bulk cytosol declines slowly partly due to futile recycling of Ca through the endoplasmic reticulum.

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193 Optogenetic Stimulation of Motor Cortex Neurons Promotes Functional Recovery After Stroke

Neurosurgery ◽

10.1227/01.neu.0000432783.58847.ba ◽

2013 ◽

Vol 60 ◽

pp. 184

Author(s):

Michelle Cheng ◽

Wyatt J. Woodson ◽

Eric Wang ◽

Stephanie Wang ◽

GuoHua Sun ◽

...

Keyword(s):

Motor Cortex ◽

Functional Recovery ◽

Optogenetic Stimulation ◽

Stimulation Of

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Brain-wide neural dynamics of poststroke recovery induced by optogenetic stimulation

Science Advances ◽

10.1126/sciadv.abd9465 ◽

2021 ◽

Vol 7 (33) ◽

pp. eabd9465

Author(s):

Shahabeddin Vahdat ◽

Arjun Vivek Pendharkar ◽

Terrance Chiang ◽

Sean Harvey ◽

Haruto Uchino ◽

...

Keyword(s):

Functional Recovery ◽

Primary Motor Cortex ◽

Neural Circuits ◽

Neural Circuit ◽

Neural Dynamics ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Optogenetic Stimulation ◽

Important Mediator ◽

Stimulation Of

Poststroke optogenetic stimulations can promote functional recovery. However, the circuit mechanisms underlying recovery remain unclear. Elucidating key neural circuits involved in recovery will be invaluable for translating neuromodulation strategies after stroke. Here, we used optogenetic functional magnetic resonance imaging to map brain-wide neural circuit dynamics after stroke in mice treated with and without optogenetic excitatory neuronal stimulations in the ipsilesional primary motor cortex (iM1). We identified key sensorimotor circuits affected by stroke. iM1 stimulation treatment restored activation of the ipsilesional corticothalamic and corticocortical circuits, and the extent of activation was correlated with functional recovery. Furthermore, stimulated mice exhibited higher expression of axonal growth–associated protein 43 in the ipsilesional thalamus and showed increased Synaptophysin+/channelrhodopsin+ presynaptic axonal terminals in the corticothalamic circuit. Selective stimulation of the corticothalamic circuit was sufficient to improve functional recovery. Together, these findings suggest early involvement of corticothalamic circuit as an important mediator of poststroke recovery.

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Boosting generalized recovery by combined optogenetic stimulation and training after stroke

10.1101/2020.03.05.974972 ◽

2020 ◽

Cited By ~ 1

Author(s):

Emilia Conti ◽

Anna Letizia Allegra Mascaro ◽

Alessandro Scaglione ◽

Giuseppe de Vito ◽

Francesco Calugi ◽

...

Keyword(s):

Cortical Excitability ◽

Functional Restoration ◽

Cortical Activation ◽

Motor Training ◽

Ischemic Event ◽

Optogenetic Stimulation ◽

Repetitive Motor ◽

And Training ◽

Recovery Of Motor Function ◽

Stimulation Of

AbstractAn ischemic event is followed by extensive changes in cortical excitability involving both hemispheres. Plasticity in the injured hemisphere plays a crucial role in poststroke motor recovery and it is a primary target for rehabilitation therapy. Though stimulation of the ipsilesional motor cortex, especially when paired with motor training, facilitates plasticity and functional restoration, the mechanisms underneath the reshaping of cortical functionality are widely unknown. Here, we designed a protocol of optogenetic stimulation of the peri-infarct region as a neuro-plasticizing treatment coupled with a repetitive motor training. This treatment promoted a generalized recovery in forelimb function and the rescue of the essential features of cortical activation profiles during the execution of the motor training. The present work, by exploiting different approaches, provides a fundamental means to better understand the mechanisms underlying the recovery of motor function.

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Optogenetic stimulation of complex spatio-temporal activity patterns by acousto-optic light steering probes cerebellar granular layer integrative properties

Scientific Reports ◽

10.1038/s41598-018-32017-w ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 1

Author(s):

Oscar Hernandez ◽

Katarzyna Pietrajtis ◽

Benjamin Mathieu ◽

Stéphane Dieudonné

Keyword(s):

Granular Layer ◽

Activity Patterns ◽

Optogenetic Stimulation ◽

Spatio Temporal ◽

Stimulation Of

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Large-scale all-optical dissection of motor cortex connectivity reveals a segregated functional organization of mouse forelimb representations

10.1101/2021.07.15.452461 ◽

2021 ◽

Author(s):

Francesco Resta ◽

Elena Montagni ◽

Giuseppe de Vito ◽

Alessandro Scaglione ◽

Anna Letizia Allegra Mascaro ◽

...

Keyword(s):

Motor Cortex ◽

Large Scale ◽

Functional Organization ◽

Voluntary Movements ◽

Motor Representation ◽

Activation Patterns ◽

Optogenetic Stimulation ◽

All Optical ◽

The Brain ◽

Stimulation Of

In rodent motor cortex, the rostral forelimb area (RFA) and the caudal forelimb area (CFA) are major actors in orchestrating the control of forelimb complex movements. However, their intrinsic connections and reciprocal functional organization are still unclear, limiting our understanding of how the brain coordinates and executes voluntary movements. Here we causally probed cortical connectivity and activation patterns triggered by transcranial optogenetic stimulation of ethologically relevant complex movements exploiting a novel large-scale all-optical method in awake mice. Results show specific activation features for each movement class, providing evidence for a segregated functional organization of CFA and RFA. Importantly, we identified a second discrete lateral grasping representation area, namely lateral forelimb area (LFA), with unique connectivity and activation patterns. Therefore, we propose the LFA as a distinct motor representation in the forelimb somatotopic motor map.

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