Transcript Figure 2
Voltage-Sensitive Dye Optical Imaging Vassiliy Tsytsarev Department of Anatomy and Neurobiology University of Maryland School of Medicine E-mail: [email protected] http://oilab.seas.wustl.edu -- 1 Principles of Voltage-Sensitive Dye Optical Imaging RH-795 chemical structure Unbound to the lipid bilayer dye molecules are not fluorescent Dye interactions with the lipid bilayer Bound dye molecules are fluorescent (after: Grinvald et al. 2001. In-vivo Optical imaging of cortical architecture and dynamics) http://oilab.seas.wustl.edu -- 2 Main Parts of the VSD Imaging Setup CCD camera Emission Filter (695 nm LP) Excitation Filter (620± 20 nm Dichroic mirror Electrical stimulation LFP recording Light Shutter Intracortical Injection http://oilab.seas.wustl.edu -- 3 How VSD works? VSD vs fast IOS Electrode 1 mm Frame = 10 ms (After: Tsytsarev et al, 2008 Imaging cortical electrical stimulation in vivo: fast intrinsic optical signal versus voltage-sensitive dyes) http://oilab.seas.wustl.edu -- 4 VSD Imaging of Tonotopicity Color-coded tonotopic map of sound frequencies showing the organization of subfields of the auditory cortex 1 kHz 5 kHz 1 kHz 5 kHz 7 kHz 7 kHz (After: Tsytsarev et al, 2009. Optical imaging of interaural time difference representation in rat auditory cortex) http://oilab.seas.wustl.edu -- 5 Voltage-Sensitive Dye Optical Imaging of the Auditory Cortex Where is “Where” in the brain? http://oilab.seas.wustl.edu -- 6 Interaural Time Difference (ITD) Binaural click produces the sensation of a sound source to the left, in front of, or to the right of the animal. The angle is determined by the Interaural Time Difference (ITD) (After: Tsytsarev et al, 2009. Optical imaging of interaural time difference representation in rat auditory cortex) http://oilab.seas.wustl.edu -- 7 Imaging of the ITD Representation sound stimulus onset Click leading: Red: contralateral Green: ipsilateral Blue: (ITD = 0) (After: Tsytsarev et al, 2009. Optical imaging of interaural time difference representation in rat auditory cortex) http://oilab.seas.wustl.edu -- 8 Conclusion l The virtual map of auditory space in rat auditory cortex does not exist but l Patterns of neural activity recorded in response to binaural click presentations can encode ITD http://oilab.seas.wustl.edu -- 9 Vibrissae System: Optical Imaging Research The main goal: to create a functional map of the directional sensitivity of the barrel field using Voltage-Sensitive Dye Optical Imaging http://oilab.seas.wustl.edu -- 10 Vibrissae System: Angular Selectivity in the Barrel Field? Stimuli Arrangement (color coded) 1 mm Whisker’s Stimulator VSD optical patterns evoked http://oilab.seas.wustl.edu -- 11 by different stimuli Studying of the Cortical Representation of Whisker Directional Deflection Using Voltage-Sensitive Dye Optical Imaging VSD Pseudocolor Pattern in the Region of Interest Magnetized Whisker inside the Stimulator Barrel Field Direction of the Deflection http://oilab.seas.wustl.edu -- 12 Barrel Field Voltage-Sensitive Dye Optical Imaging Extracted brain Histology (Cytochrome-c oxidase) Barrel field Brain opening and area of recording ΔF/F(%) 0.15 Integrated signal in response to different stimuli 0 -0.15 0 20 time, ms http://oilab.seas.wustl.edu -- 13 Activity Centers in the Single Coordinates System Borders of the Activity Patterns after thresholding 0.5 mm http://oilab.seas.wustl.edu -- 14 Disposition of Centers of Mass of Activity Patterns Stimulus 3 Stimulus 2 Stimulus 4 Stimulus 1 http://oilab.seas.wustl.edu -- 15 Acknowledgments Drs. Shigeru Tanaka, Hidenao Fukuyama, Kazuyuki Imamura, Ayako Ajima, Hisayuki Ojima, Minoru Kimura and Jerom Ribot – Brain Science Institute of RIKEN and Kyoto University, Japan Dr. Sonya Bahar, Director, Center for Neurodynamics, University of Missouri at St. Louis Daisuke Takeshita Douglas Joseph Brumm and Dr. Micheal Hoffman – Center for Neurodynamics, University of Missouri at St. Louis Song Hu, Junjie Yao, Li Li – Ph.D. student of the Washington University in St. Louis Drs Konstantin Maslov and Lihong Wang – Department of Biomedical Engineering, Washington University in St. Louis http://oilab.seas.wustl.edu -- 16 Thank you very much for your attention http://oilab.seas.wustl.edu -- 17