Sonogenetic control of mammalian cells using exogenous Transient Receptor Potential A1 channels

Marc Duque,Aditya Vasan,Uri Magaram,Sreekanth H Chalasani,Jose Mendoza Lopez,Corinne A Lee-Kubli,James Friend,Janki Patel,Eric Edsinger,Yusuf Tufail,Rani Shiao,Connor Weiss,Ahana Chakraborty

doi:10.1038/s41467-022-28205-y

Abstract

Ultrasound has been used to non-invasively manipulate neuronal functions in humans and other animals. However, this approach is limited as it has been challenging to target specific cells within the brain or body. Here, we identify human Transient Receptor Potential A1 (hsTRPA1) as a candidate that confers ultrasound sensitivity to mammalian cells. Ultrasound-evoked gating of hsTRPA1 specifically requires its N-terminal tip region and cholesterol interactions; and target cells with an intact actin cytoskeleton, revealing elements of the sonogenetic mechanism. Next, we use calcium imaging and electrophysiology to show that hsTRPA1 potentiates ultrasound-evoked responses in primary neurons. Furthermore, unilateral expression of hsTRPA1 in mouse layer V motor cortical neurons leads to c-fos expression and contralateral limb responses in response to ultrasound delivered through an intact skull. Collectively, we demonstrate that hsTRPA1-based sonogenetics can effectively manipulate neurons within the intact mammalian brain, a method that could be used across species.

Highlights

Ultrasound has been used to non-invasively manipulate neuronal functions in humans and other animals
We found that human Transient Receptor Potential A1 (hsTRPA1) was more effective than these other candidates at frequencies of 1 MHz, 2 MHz, and 7 MHz, confirming that hsTRPA1 channel was sensitive to a broad range of ultrasound stimuli (Fig. 1f)
Treating neurons with a TRPV1 antagonist had no effect on their ultrasound responses (Supplementary Fig. S8h), thereby ruling out the TRPV1 heat-responsive channel’s contribution to ultrasound sensitivity in TRPA1-expressing neurons either directly or through a synergistic interaction[45]. These results are consistent with a recent study that identified multiple mechanosensitive channels that can transduce calcium responses to ultrasound in control neurons[16]. These results show that ultrasound can directly activate AAV9-hsTRPA1 transduced neurons, leading to intracellular calcium influx, which may be amplified by voltage-gated sodium channels

Summary

Introduction

Ultrasound has been used to non-invasively manipulate neuronal functions in humans and other animals. We and others have found evidence for the involvement of mechanosensitive channels in ultrasound responses of naïve rodent neurons in vitro[16] and C. elegans neurons in vivo[17,18] This provides a potential path toward the development of a broadly usable sonogenetic tool that would target exogenous proteins to specific cells, thereby rendering them sensitive to ultrasound stimuli at pressures and durations that do not affect naïve cells. While lower frequency stimuli are more likely to penetrate biological tissue, they have large focal areas making it difficult to target specific brain regions (Fig. 1a) To overcome these challenges, we use ultrasound at 7 MHz, which can be focused to a small volume of 107 μm[3], suitable for applications in the rodent model. Pharmacology, electrophysiology, and comparative sequence analysis, as well as behavioral, and histological analyses to demonstrate that a mammalian protein, Homo sapiens transient receptor potential A1 (hsTRPA1), confers ultrasound sensitivity to cells in vitro and in vivo, thereby establishing a sonogenetic tool in mammals

Methods

Results

Conclusion