bioRxiv Science⌕ Search

Biology subjects

Ashbaugh, R. C.

Publications and source records attributed to Ashbaugh, R. C..

4 recordsLinked to original sources

A putative design for electromagnetic activation of split proteins for molecular and cellular manipulation

The ability to manipulate cellular function using an external stimulus is a powerful strategy for studying complex biological phenomena. One approach to modulate the function of the cellular environment is split proteins. In this method, a biologically active protein or an enzyme is fragmented so that it reassembles only upon a specific stimulus. While there are many tools available to induce these systems, nature has provided other mechanisms that can be utilized to expand the split protein toolbox. Here we show a novel method for reconstituting split proteins using magnetic stimulation. We have found that the Electromagnetic Perceptive Gene (EPG) changes conformation due to magnetic fields stimulation. By fusing split fragments of a certain protein to both termini of the EPG, the fragments can be reassembled into a functional protein under magnetic stimulation due to conformational change. We show this effect with three separate split proteins; NanoLuc, APEX2, and Herpes Simplex Virus Type-1 Thymidine Kinase. Our results show for the first time, that reconstitution of split proteins can be achieved only with magnetic fields. We anticipate that this study will be a starting point for future magnetically inducible split protein designs for cellular perturbation and manipulation. With this technology, we can help to expand the toolbox of the split protein platform and allow better elucidation of complex biological systems.

synthetic biology↗

Bioelectromagnetic platform for stimulation

Magnetogenetics is a new field that utilizes electromagnetic fields to remotely control cellular activity. In addition to the development of the biological genetic tools, this approach requires designing hardware with a specific set of demands for the electromagnets used to provide the desired stimulation for electrophysiology and imaging experiments. Here we present a universal stimulus delivery system comprised of four magnet designs compatible with electrophysiology, fluorescence and luminescence imaging, microscopy, and freely behaving animal experiments. The overall system includes a low-cost stimulation controller which enables rapid switching between active and sham stimulation trials as well as precise control of stimulation delivery.

bioengineering↗

Swimming direction of the Glass Catfish, Kryptopterus bicirrhis, is responsive to magnetic stimulation

Several marine species have developed a magnetic perception that is essential for navigation and detection of prey and predators. One of these species is the transparent glass catfish that contains an ampullary organ dedicated to sense magnetic fields. Here we examine the behavior of the glass catfish in response to static magnetic fields which will provide valuable insight on function of this magnetic response. By utilizing state of the art animal tracking software and artificial intelligence approaches, we quantified the effects of magnetic fields on the swimming direction of glass catfish. The results demonstrate that glass catfish placed in a radial arm maze, consistently swim away from magnetic fields over 20 {micro}T and show adaptability to changing magnetic field direction and location.

animal behavior and cognition↗

Non-invasive neuromodulation using rTMS and the Electromagnetic-Preceptive Gene (EPG) facilitates plasticity after nerve injury

Peripheral nerve injury leads to altered cortical excitation-inhibition balance which is associated with sensory dysfunctions. We tested if non-invasive repetitive transcranial magnetic stimulation (rTMS) which has shown to induce neuronal excitability, and cell-specific magnetic activation via the Electromagnetic-perceptive gene (EPG) which is a novel gene that was identified and cloned from Kryptopterrus bicirrhis and demonstrated to evoke neural responses when magnetically stimulated, can restore cortical excitability. A battery of behavioral tests, fMRI and immunochemistry were performed in the weeks following limb denervation in rats. The results demonstrate that neuromodulation significantly improved long-term mobility, decreased anxiety and enhanced neuroplasticity. The study also identifies the acute post-injury phase as a critical time for intervention. Moreover, the results implicate EPG as an effective cell-specific neuromodulation approach. Together, these results reinforce the growing amount of evidence from human and animal studies that are establishing neuromodulation as an effective strategy to promote plasticity and rehabilitation.

neuroscience↗