Voltage-Sensitive Dye Optical Imaging
Vassiliy Tsytsarev
Department of Anatomy and Neurobiology
University of Maryland School of Medicine
E-mail: tsytsarev@umaryland.edu
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