Meeting Banner
Abstract #2881

The Influence of Laser Power and Pulse Characteristics on the Optogenetically Induced BOLD Signal of Excitatory Neurons in the Mouse Hippocampus at 9.4T

Philipp Lebhardt1, Wolfgang Kelsch2, 3, Claudia Falfan-Melgoza1, Gabriele Ende1, Alexander Sartorius2, Wolfgang Weber-Fahr1

1NeuroImaging, Central Institute of Mental Health, Mannheim, Germany; 2Clinic of Psychiatry and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany; 3Cinical Neurobiology, University of Heidelberg, Hiedelberg, Germany

In this study we were interested in the influence of laser power and stimulation frequency on the optogenetically induced BOLD signal of the hippocampal network in mice. We induced expression of channelrhodopsin-2 in Ca2+/calmodulin-dependent protein kinase II-expressing neurons by virus injection. Laser stimulation was periodically applied through an optical fiber in the left hippocampus with block and event related designs using different power and stimulation characteristics. We found activation and deactivation due to laser heating effects even at low power levels and diverse activation patterns in dependency of stimulation length and frequency

Keywords

according activated activation adaption addition additionally already altered analyzed anatomically anesthetized animal animals applied basis block bold brain breathing burst bursts central character characteristics clinic close coil conducted considerably consisted convolved correction cortex covariates dataset deactivation dependent design diameter distant dorsal double duration durations equipped especially event excitation excitatory excite expression fiber finite freely frequencies frequency function greater green guidance health heating highly human implanted impulse increasing indicated induced influence injection insertion institute interestingly intervals investigate investigated isotropic kernel laser length linear mapping matrix measured mental mice modulated motion mouse movement nature networks neurobiology neuronal neurons noise optic optical paradigm pattern period periodically physiological population power preprocessing process prolonged protein psychiatry psychotherapy pulse pulsed reaches receive recombination related repetition resonator respectively response rest reversed sartorius scanned scanner secondary selectively sham shaped short shorter smoothed smoothing stepwise stimulation strength strong surface transmit types upon view virus visible volume wavelength weber week yielded