Cationic Channelrhodopsin from the Alga Platymonas subcordiformis as a Promising Optogenetic Tool

Idzhilova, Olga; Смирнова, Г. Р.; Petrovskaya, L. E.; Kolotova, Darya A.; Оstrovsky, М. А.; Malyshev, Aleksey

doi:10.1134/s0006297922110116

Cited by 3 publications

(2 citation statements)

References 13 publications

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“…To circumvent this problem, we decided to use an optogenetic approach for the tetanization of neurons. Classical channelrhodopsin2, due to the pronounced sensitization of responses during rhythmic stimulation, allows for the induction of controlled bursts of action potentials at frequencies up to 20-30 Hz, but not higher [31]. Therefore, we used the fast channelrhodopsin oChIEF, which allows the efficient optogenetic stimulation of neurons at frequencies around 100 Hz [32], thus allowing us to reproduce conventional plasticity-induction protocols.…”

Section: Resultsmentioning

confidence: 99%

Plasticity of Response Properties of Mouse Visual Cortex Neurons Induced by Optogenetic Tetanization In Vivo

Smirnov,

Osipova,

Smirnova

et al. 2024

CIMB

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Heterosynaptic plasticity, along with Hebbian homosynaptic plasticity, is an important mechanism ensuring the stable operation of learning neuronal networks. However, whether heterosynaptic plasticity occurs in the whole brain in vivo, and what role(s) in brain function in vivo it could play, remains unclear. Here, we used an optogenetics approach to apply a model of intracellular tetanization, which was established and employed to study heterosynaptic plasticity in brain slices, to study the plasticity of response properties of neurons in the mouse visual cortex in vivo. We show that optogenetically evoked high-frequency bursts of action potentials (optogenetic tetanization) in the principal neurons of the visual cortex induce long-term changes in the responses to visual stimuli. Optogenetic tetanization had distinct effects on responses to different stimuli, as follows: responses to optimal and orthogonal orientations decreased, responses to null direction did not change, and responses to oblique orientations increased. As a result, direction selectivity of the neurons decreased and orientation tuning became broader. Since optogenetic tetanization was a postsynaptic protocol, applied in the absence of sensory stimulation, and, thus, without association of presynaptic activity with bursts of action potentials, the observed changes were mediated by mechanisms of heterosynaptic plasticity. We conclude that heterosynaptic plasticity can be induced in vivo and propose that it may play important homeostatic roles in operation of neural networks by helping to prevent runaway dynamics of responses to visual stimuli and to keep the tuning of neuronal responses within the range optimized for the encoding of multiple features in population activity.

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Section: Resultsmentioning

confidence: 99%

Plasticity of Response Properties of Mouse Visual Cortex Neurons Induced by Optogenetic Tetanization In Vivo

Smirnov,

Osipova,

Smirnova

et al. 2024

CIMB

View full text Add to dashboard Cite

show abstract

“…To circumvent this problem, we decided to use an optogenetic approach for tetanization of neurons. Classical channelrhodopsin2, due to the pronounced sensitization of responses during rhythmic stimulation, allows to induce controlled bursts of action potentials at frequencies up to 20-30 Hz, but not higher [33]. Therefore, we used the fast channelrhodopsin oChIEF , which allows efficient optogenetic stimulation of neurons at frequencies around 100 Hz [34], thus letting us to reproduce conventional plasticity-induction protocols.…”

Section: Resultsmentioning

confidence: 99%

PLASTICITY OF RESPONSE PROPERTIES OF MOUSE VISUAL CORTEX NEURONS INDUCED BY OPTOGENETIC TETANIZATIONIN VIVO

Osipova,

Smirnov,

Smirnova

et al. 2023

Preprint

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Heterosynaptic plasticity, along with Hebbian homosynaptic plasticity, is an important mechanism ensuring stable operation of learning neuronal networks. However, whether heterosynaptic plasticity occurs in the whole brain in vivo, and what role(s) in brain function in vivo it could play, remains unclear. Here, we used an optogenetics approach to apply a model of intracellular tetanization, which was established and employed to study heterosynaptic plasticity in brain slices, to study plasticity of response properties of neurons in mouse visual cortex in vivo. We show that optogenetically evoked high-frequency bursts of action potentials (optogenetic tetanization) in principal neurons of the visual cortex induce long-term changes of responses to visual stimuli. Optogenetic tetanization had distinct effects on responses to different stimuli: responses to optimal and orthogonal orientations decreased, response to null direction did not change, and responses to oblique orientations increased. As a result, direction selectivity of the neurons decreased, and orientation tuning became broader. Since optogenetic tetanization was a purely postsynaptic protocol, applied in the absence of sensory stimulation, and thus without association of presynaptic activity with bursts of action potentials, the observed changes were mediated by mechanisms of heterosynaptic plasticity. We conclude that heterosynaptic plasticity can be induced in vivo and propose that it may play important homeostatic roles in operation of neural networks by helping to prevent runaway dynamics of responses to visual stimuli and to keep the tuning of neuronal responses within the range optimized for encoding of multiple features in population activity.

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Neutrophil-Mimetic Upconversion Photosynthetic Nanosystem Derived from Microalgae for Targeted Treatment of Thromboembolic Stroke

Quan,

Liu,

Chen

et al. 2024

ACS Nano

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Thromboembolic stroke constitutes the majority of brain strokes, resulting in elevated mortality and morbidity rates, as well as significant societal and economic burdens. Although intravenous thrombolysis serves as the standard clinical treatment, its narrow therapeutic window and the inflammatory response induced by tissue plasminogen activator (tPA) administration limit its efficacy. In the initial stages of stroke, the abrupt cessation of blood flow leads to an energy metabolism disorder, marked by a substantial decrease in adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH) levels, causing irreversible damage to neural cells. In this study, we introduce a neutrophilmimetic, microalgae-derived upconversion photosynthetic nanosystem designed for targeted treatment of thromboembolic stroke. This system features upconversion nanoparticles coated with a thylakoid membrane and wrapped in an activated neutrophil membrane, further decorated with ROS-responsive thrombolytic tPA on its surface. The neutrophil-mimetic design facilitates high targeting specificity and accumulation at the thrombus site after intravenous administration. Upon exposure to elevated levels of reactive oxygen species (ROS) at the thrombus location, the nanosystem promptly demonstrated potent thrombolytic efficacy through the surface-modified tPA. Furthermore, near-infrared II (NIR-II) laser irradiation activated the generation of ATP and NADPH, which inhibited inflammatory cell infiltration, platelet activation, oxidative stress, and neuronal injury. This constructed nanoplatform not only showcases exceptional targeting efficiency at the stroke site and controllable release of the thrombolytic agent but also facilitates ATP/NADPH-mediated thrombolytic, anti-inflammatory, antioxidative stress, and neuroprotective effects. Additionally, it offers valuable insights into the potential therapeutic applications of microalgae-based derivatives in managing thromboembolic stroke.

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Cationic Channelrhodopsin from the Alga Platymonas subcordiformis as a Promising Optogenetic Tool

Cited by 3 publications

References 13 publications

Plasticity of Response Properties of Mouse Visual Cortex Neurons Induced by Optogenetic Tetanization In Vivo

Plasticity of Response Properties of Mouse Visual Cortex Neurons Induced by Optogenetic Tetanization In Vivo

PLASTICITY OF RESPONSE PROPERTIES OF MOUSE VISUAL CORTEX NEURONS INDUCED BY OPTOGENETIC TETANIZATIONIN VIVO

Neutrophil-Mimetic Upconversion Photosynthetic Nanosystem Derived from Microalgae for Targeted Treatment of Thromboembolic Stroke

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