One of the major research axes of our lab focuses on the development of Transcranial Radio Frequency Stimulation (TRFS), a non-invasive brain stimulation method, towards its clinical translation. To that end, our lab will 1) try to further characterize and better understand the effects of TRFS on neural activity, 2) study the translational effects of TRFS on rodent models of brain disorders, and 3) design, prepare, and execute first TRFS clinical trials.  

RF exposure can induce temperature rise in the biological tissue such as the brain. These temperature changes can affect the ongoing activity of neurons. When the thermal changes in the brain are controlled within a safe range, RF can be used as a non-invasive neuromodulation tool. In an ongoing study, we are working on establishing an RF stimulation paradigm to demonstrate the proof-of-concept for this method using a combination of RF-artifact-free (and metal-free) neural recordings, i.e., fMRI and optical imaging. 

Whether non-thermal RF energy exposure can affect ongoing neural activity or not has been the core of a several-decades-long scientific debate.  We studied the effects of continuous-wave RF radiation on neural activity monitored by electrophysiology and 1-photon calcium imaging. Our electrophysiological recordings showed a variety of significant changes in neural activity due to RF energy exposure.  Our metal implant-free RF interference-free imaging results, however, demonstrated that RF energy exposure, inducing specific absorption rates (SAR) several folds higher than allowed by regulatory limits, does not affect neural activity in a significant manner. 

Read more here.  

To accurately assess the strength of the absorbed RF energy in exposed mice brains, we developed a method for direct measurement of electric fields in-vivo using a  Bismuth Silicon Oxide (BSO) crystal sensor. This method can be used in dosimetry studies for a diverse set of applications incorporating the interaction of RF energy and biological tissue. 

Read more here.  

We have studied the effect of RF energy exposure on whole brain activity by functional Magnetic Resonance Imaging (fMRI) in mice. To do that, we developed a 3D-print design for optimal animal conditioning and experimental set-up. We extended the functionality of this design to include multi-modal imaging and host both mice and rats and made it freely available to the public with open source.  We also designed a compatible heating and cooling system to control animals' body and brain temperature.

Read more here and here.   

We use silicon probes to record neural activity (i.e. brain oscillations and spiking activity of hundreds of single neurons) in several brain regions of behaving (freely-moving and/or head-fixed) rodents. 

Using miniature head-mounted 1-photon imaging endoscopes (UCLA Miniscope) we monitor the ongoing neuronal activity of several hundreds of single neurons in different brain regions in behaving (freely moving or head-fixed) rodents. We have also developed a modified fiber-coupled version to perform artifact-free neural recording in RF energy-exposed head-fixed mice. 

We employ fiber-photometry to measure the collective activity of ensembles of cells and/or changes of different types of neuromodulators in behaving rodents.    

Using our multi-modal rodent conditioning platform, we perform different types of whole-brain imaging including Magntic Resonance Imaging (MRI), functional MRI (fMRI), Pet/CT, etc. These methods allow us to assess structural, functional, and metabolic information about rodents brain in anesthetized or awake state.   

We use custom-made and/or publicly available computational code to perform analytical calculations on various types of measured data (from physiological variables to large-scale neural activity). 

We perform physics-based numerical simulations to model different realistic scenarios and study various parameters under those conditions.  

3D print designs are fast, easy, low-cost, and incredibly efficient solutions for filling the gaps in experimental design where commercially available parts fail to satisfy the needs.  Our designs are open-source and we are happy to share them with the scientific community. They can be found here.