http://oilab.seas.wustl.edu -- 1

Voltage-Sensitive Dye Optical Imaging

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 -- 2

Principles of Voltage-Sensitive Dye Optical Imaging Principles of Voltage-Sensitive Dye Optical Imaging

RH-795 chemical structure

Dye interactions with the lipid bi-layer

Unbound to the lipid bilayer dye molecules are not fluorescent

Bound dye molecules are fluorescent

(after: Grinvald et al. 2001. In-vivo Optical imaging of cortical architecture and dynamics)

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Main Parts of the VSD Imaging SetupMain Parts of the VSD Imaging Setup

Emission Filter(695 nm LP)

CCD camera

Dichroic mirror

Electrical stimulation

LFP recording Intracortical Injection

Excitation Filter(620± 20 nm

Light Shutter

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How VSD works?How VSD works?

(After: Tsytsarev et al, 2008 Imaging cortical electrical stimulation in vivo: fast intrinsic optical signal versus voltage-sensitive dyes)

Electrode

1 mm

Frame = 10 ms

VSD vs fast IOS

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VSD Imaging of TonotopicityVSD Imaging of Tonotopicity

1 kHz 5 kHz 7 kHz

Color-coded tonotopic map of sound frequencies showing theorganization of subfields of the auditory cortex

(After: Tsytsarev et al, 2009. Optical imaging of interaural time difference representation in rat auditory cortex)

1 kHz 5 kHz 7 kHz

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Voltage-Sensitive Dye Optical Imaging of the Auditory CortexVoltage-Sensitive Dye Optical Imaging of the Auditory Cortex

Where is

in the brain?

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Interaural Time Difference (ITD)Interaural Time Difference (ITD)

Binaural click produces the sensation of a sound source tothe 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)

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Imaging of the ITD RepresentationImaging of the ITD Representation sound stimulusonset

Click leading:

Red: contralateralGreen: ipsilateral Blue: (ITD = 0)

(After: Tsytsarev et al, 2009. Optical imaging of interaural time difference representation in rat auditory cortex)

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ConclusionConclusion

The virtual map of auditory space in rat auditory cortex does not exist

but

Patterns of neural activity recorded in response to binaural click presentations can encode ITD

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Vibrissae System: Optical Imaging ResearchVibrissae 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

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Vibrissae System: Angular Selectivity in the Barrel Field?Vibrissae System: Angular Selectivity in the Barrel Field?

1 mm

Stimuli Arrangement(color coded)

Whisker’s StimulatorVSD optical patterns evoked by different stimuli

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Studying of the Cortical Representation of Whisker Directional Deflection Using Voltage-Sensitive Dye Optical Imaging

Studying of the Cortical Representation of Whisker Directional Deflection Using Voltage-Sensitive Dye Optical Imaging

Barrel Field

VSD Pseudocolor Pattern in the Region of

Interest

Direction of the Deflection

Magnetized Whisker inside the Stimulator

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Barrel Field Voltage-Sensitive Dye Optical ImagingBarrel Field Voltage-Sensitive Dye Optical ImagingHistology

(Cytochrome-c oxidase)

Extracted brain

Barrel field Brain opening

and area of recording

0.15

0

-0.15

ΔF

/F

(%)

0 20 time, ms

Integrated signal in response to differentstimuli

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Activity Centers in the Single Coordinates SystemActivity Centers in the Single Coordinates System

Borders of the Activity Patterns after thresholding

0.5 mm

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Disposition of Centers of Mass of Activity PatternsDisposition of Centers of Mass of Activity Patterns

Stimulus 1

Stimulus 2

Stimulus 3

Stimulus 4

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AcknowledgmentsAcknowledgments

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

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Thank you very much for your attention Thank you very much for your attention