We believe noninvasive brain stimulation such as transcranial electrical stimulation (tES) can have tremendous implications for neuro-engineering applications and the treatment of Alzheimer’s Disease, but only if we understand and precisely control the mechanisms of tES. While there is an extensive effort to evaluate the potential of tES to modify disease outcomes, we lack a comprehensive understanding of how they elicit their myriad effects. To fill this gap in knowledge,  we are currently investigating how different cell types, beautifully organized across the cortical layers, respond electrophysiologically and transcriptionally to tES. We test several tES paradigms such as anodal and cathodal tDCS (transcranial direct current stimulation) and theta & gamma tACS (transcranial alternating current stimulation). We focus on CaMKII excitatory neurons and PV and SST interneurons to study how these cell types regulate tES evoked electrical activity across the cortical layers locally. In addition, we have elucidated the indispensability of CH neurons in synchronizing neural activity between cerebral brain hemispheres. Therefore, we study if and how tES applied to one brain hemisphere affects the electrical activity in the contralateral brain hemisphere.