Potassium-selective channelrhodopsins can exert hyper- or depolarizing effects in excitable cells ofCaenorhabditis elegans, depending on experimental condition DOI Creative Commons

Christiane Ruse,

Marius Seidenthal,

Linda Tillert

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: June 14, 2024

Abstract One of the most frequent applications optogenetic tools is for depolarization and stimulation excitable cells such as neurons muscles. Equally important, but less frequently used, are inhibitory that suppress activity through cellular hyperpolarization. These often rely on chloride conductance. Yet, in vivo , re- hyperpolarization typically mediated by potassium. In recent years, light-gated ion channels with a high preference potassium were identified (Kalium channelrhodopsins, KCRs), their potential described different organisms. Here, we characterized Hc KCR1 WiChR, cholinergic muscles Caenorhabditis elegans . Hyperpolarization these cell types both induces muscle relaxation and, consequently, an elongation animals. Thus, analyzed body length before, during, after illumination, to assess KCR effectiveness, benchmark parameters like light intensity duration. For neurons, continuous illumination at intensities (1-4.5 mW/mm 2 ) evoked only transient elongation, while 0.1 could maintain inhibition duration stimulus some transgenic strains. animals expressing WiChR wall or again observed brief during however, still stimulus, this changed contraction, corresponding depolarization. This effect was long lasting, required dozens seconds reversion, be reduced pulsed fully avoided efficient channel activation using green orange light. Hence, KCRs can applied hyperpolarize C. cells, require optimized parameters. Article summary To inhibit light-gated, potassium-selective (KCRs) used. study explores whether induce illumination. While achieved, depending conditions, authors unexpectedly also excitation. effects may occur due combination conductivity KCRs, partial conductance other cations. findings highlight need specific experimental conditions future studies utilizing tools. The present partially avoid unwanted depolarizing effects.

Language: Английский

Theoretical analysis of low-power deep synergistic sono-optogenetic excitation of neurons by co-expressing light-sensitive and mechano-sensitive ion-channels DOI Creative Commons
Sukhdev Roy,

Gur Pyari,

Himanshu Bansal

et al.

Communications Biology, Journal Year: 2025, Volume and Issue: 8(1)

Published: March 6, 2025

The present challenge in neuroscience is to non-invasively exercise low-power and high-fidelity control of neurons situated deep inside the brain. Although, two-photon optogenetic excitation can activate millimeter depth with sub-cellular specificity millisecond temporal resolution, it also cause heating targeted tissue. On other hand, sonogenetics modulate cellular activity expressed mechano-sensitive proteins deeper areas brain less spatial selectivity. We a theoretical analysis synergistic sono-optogenetic method overcome these limitations by co-expressing (MscL-I92L) ion-channel light-sensitive (CoChR/ChroME2s/ChRmine) hippocampal neurons. It shown that presence low-amplitude subthreshold ultrasound pulses, threshold for neural spiking reduces drastically 73% MscL-I92L-CoChR (0.021 mW/µm2), 66% MscL-I92L-ChroME2s (0.029 64% MscL-I92L-ChRmine (0.013 mW/µm2) at 5 Hz. allows up 1.2 cm combination. useful design new experiments multimodal neuroprosthetic devices circuits.

Language: Английский

Citations

1
Direct Stimulation of Gastric Smooth Muscle Cells via Gq Proteins With Light DOI Creative Commons

David Zipf,

Markus Vogt, Udhayabhaskar Sathyanarayanan

et al.

Neurogastroenterology & Motility, Journal Year: 2025, Volume and Issue: unknown

Published: March 31, 2025

ABSTRACT Background Optogenetics is a cutting‐edge approach that can enable direct stimulation of gastric smooth muscle cells (SMC) by combining cell‐specific overexpression light‐sensitive proteins with light stimulation. We previously demonstrated optogenetic SMC via depolarization restore contractility and food propulsion could become new treatment strategy for gastroparesis. The human receptor Neuropsin (hOPN5) enables activation G q signaling UV light. Herein, we explore this SMC. Methods used transgenic mouse model expressing hOPN5 in fusion eYFP. Antral longitudinal strips were isometric force measurements whole stomachs intragastric pressure measurements, comparing to other stimuli. Adeno‐associated virus (AAV) serotypes screened efficiency transducing cultured SMC, transduced tested Ca 2+ imaging. Results expression was restricted found ~1/3 the stomach. induced increased only mice similarly electrical field reached approximately 1/3 global muscarinic activation. Importantly, optical remained effective an ex vivo gastroparesis model. AAV 2.5 far most serotype transduction, triggered transients hOPN5. Conclusion tool directly stimulate control Thus, it additional complementary light‐induced membrane motility.

Language: Английский

Citations

0
Potassium-selective channelrhodopsins can exert hyper- or depolarizing effects in excitable cells ofCaenorhabditis elegans, depending on experimental condition DOI Creative Commons

Christiane Ruse,

Marius Seidenthal,

Linda Tillert

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: June 14, 2024

Abstract One of the most frequent applications optogenetic tools is for depolarization and stimulation excitable cells such as neurons muscles. Equally important, but less frequently used, are inhibitory that suppress activity through cellular hyperpolarization. These often rely on chloride conductance. Yet, in vivo , re- hyperpolarization typically mediated by potassium. In recent years, light-gated ion channels with a high preference potassium were identified (Kalium channelrhodopsins, KCRs), their potential described different organisms. Here, we characterized Hc KCR1 WiChR, cholinergic muscles Caenorhabditis elegans . Hyperpolarization these cell types both induces muscle relaxation and, consequently, an elongation animals. Thus, analyzed body length before, during, after illumination, to assess KCR effectiveness, benchmark parameters like light intensity duration. For neurons, continuous illumination at intensities (1-4.5 mW/mm 2 ) evoked only transient elongation, while 0.1 could maintain inhibition duration stimulus some transgenic strains. animals expressing WiChR wall or again observed brief during however, still stimulus, this changed contraction, corresponding depolarization. This effect was long lasting, required dozens seconds reversion, be reduced pulsed fully avoided efficient channel activation using green orange light. Hence, KCRs can applied hyperpolarize C. cells, require optimized parameters. Article summary To inhibit light-gated, potassium-selective (KCRs) used. study explores whether induce illumination. While achieved, depending conditions, authors unexpectedly also excitation. effects may occur due combination conductivity KCRs, partial conductance other cations. findings highlight need specific experimental conditions future studies utilizing tools. The present partially avoid unwanted depolarizing effects.

Language: Английский

Citations

1