Abstract #0100

The Laminar Specific Neuronal Responses to Forepaw & Optogenetics Stimulations

John Downey¹, Nan Li^2,3, Assaf A. Gilad^4,5, Piotr Walczak^4,5, Nitish V. Thakor³, Galit Pelled^1,4

¹F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; ²F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; ³The Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA; ⁴The Russell H. Morgan Department of Radiology & Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; ⁵Cellular Imaging Section, Vascular Biology Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA

Changes in the laminar communication associated with cortical plasticity have been difficult to assess in vivo. Recent advances in optogenetics enable immediate and reversible manipulations of neuronal firing rate by using channelrhodopsin (ChR2). Here we determined the laminar specific neuronal responses in the primary somatosensory cortex (S1) of ChR2 engineered rats. The laminar neuronal responses detected by BOLD fMRI and by local field potentials within S1 were compared between forepaw and ChR2 stimulations. Both forepaw and ChR2 stimulations showed a peak in BOLD and electrophysiology responses in lamina 4, demonstrating the capability of fMRI to resolve optogenetics modulated laminar communication.