MiCAM is a series of high-speed cameras specially designed to detect
extremely small changes in light levels with optimal high speed,
high resolution, and a high signal-to-noise (S/N) ratio. All cameras
are designed and manufactured in Japan.
What are voltage-sensitive dyes?
voltage-sensitive dyes are fluorescent dyes whose intensity changes
in response to membrane potential. By using these dyes as chemical
probes and capturing the changes in light intensity with a
high-speed imaging device, it is possible to visualize in real time
where, when, and to what extent excitation and inhibition occur in
the brain and heart.
What are the advantages of Voltage-Sensitive Dye Imaging (VSDI)?
Compared to conventional electrophysiological recordings using
electrodes, Voltage-Sensitive Dye Imaging (VSDI) offers three major
advantages:
Non-invasive recording: Since
changes in action potentials in brain or heart tissue are captured
with light, there is no physical damage from electrodes. It also
allows for the simultaneous visualization of activity and signal
propagation over a wide field of view.
Easy recording without the need for electrophysiological
skills:
No experience with electrophysiological techniques such as
patch-clamping or intracellular recording is required. Compared to
conventional techniques using electrodes, it allows for the
acquisition of more data, recording signals at 10,000 to 65,536
points.
Capable of multi-parametric recording (Vm, Ca2+, metabolism,
etc.):
By selecting the appropriate fluorescent dyes and filters, it is
possible to simultaneously record changes not only in membrane
potential but also in calcium concentration and metabolism-related
indicators.
What is optical mapping of membrane potential?
Optical mapping is a technique based on conventional
electrophysiology that uses optical imaging methods to further
understand membrane potential in cellular networks, both spatially
and temporally. Unlike conventional patch-clamp recordings using
electrodes, membrane potential is optically recorded in two
dimensions using voltage-sensitive dyes. This optical mapping method
allows researchers to image a large area with minimal invasiveness.
What biological samples can be used for optical mapping?
Optical mapping technology is used for in vivo animals, tissue
slices, isolated muscle tissue, in vitro samples such as cultured
cells, and similar applications. Specific examples include isolated
hearts (Langendorff-perfused hearts, in vivo hearts), cultured
cardiomyocyte sheets, iPSC-derived cardiomyocytes, in vivo brain
(somatosensory cortex, visual cortex, auditory cortex), and brain
slices (hippocampus, somatosensory cortex, visual cortex, auditory
cortex).
What is the required system configuration for optical mapping?
The MiCAM system includes a camera, a processor, data acquisition
software, data analysis software, a software license, a personal
computer with an interface, and a PC monitor.
Additionally,
depending on the type of experiment, other equipment such as a
fluorescence microscope, a bright and stable light source, an
anti-vibration table, and an isolator are also required. The MiCAM05
is a turnkey system with hardware and software specially designed
for high-speed fluorescence imaging, and it includes a PC and
monitor as standard equipment.
What is the maximum frame rate of the MiCAM system?
Various maximum frame rates are possible with the MiCAM system,
depending on the model and settings. The MiCAM05-N256 can
achieve an ultra-high frame rate of 20,000 fps at 32 x 32 pixels,
5,556 fps at 128 x 128 pixels, and 1,923 fps at 256 x 256 pixels.
What is the THT Mesoscope and what are its advantages?
The THT Mesoscope is a tandem-lens fluorescence optical system
developed to detect faint fluorescence emitted from biological
samples at low magnification. Over the past 20 years, approximately
250 units have been sold and used in many scientific papers for
high-speed fluorescence imaging applications such as
voltage-sensitive dye imaging, GCaMP imaging, and GEVI imaging. Its
main advantages are as follows:
Much brighter than other fluorescence stereomicroscopes:
Due to its simple structure with less light loss (no eyepieces or
zoom function), a large-aperture objective lens, and custom-made
large fluorescence filters, it is approximately 30 times brighter at
1x overall magnification and 10 times brighter at 2x compared to
other fluorescence stereomicroscopes.
Imaging of the entire tissue with a wide field of view:
By combining lenses, it covers a low magnification range from
approximately 0.19x to 6.3x, enabling wide-field imaging.
The optical axis can be tilted and rotated:
A stand is available that allows the optical axis to be rotated 360
degrees left and right without needing to tilt the animal sample.
This enables imaging of the entire temporal lobe of the brain.
Simultaneous 2-3 wavelength measurement using multiple
fluorescent probes:
By using the main body as a beam splitter or connecting a beam
splitter, it is possible to perform simultaneous measurements with
different fluorescent probes or conduct photostimulation experiments
using optogenetics.
Hemodynamic correction of GCaMP signals via dual-wavelength
excitation:
When combined with the LEX9, a high-power and stable LED light
source system, it is ideal for GCaMP imaging (using 405nm and 460nm)
and other dual-wavelength imaging experiments.
What software is used for data acquisition and analysis with the
MiCAM system?
BV Workbench is used as the image acquisition software for the MiCAM
optical mapping system. In addition to image acquisition and
input/output control of the imaging system, BV Workbench also
includes analysis functions such as video playback, waveform
display, and filtering.
It features an intuitive user
interface for easy mouse operation. The previous data analysis
software was BV_Ana, but it is no longer sold or supported; the
latest version is BV Workbench.
What are SciMedia's strengths in implementing the MiCAM system?
SciMedia specializes in turnkey high-speed optical mapping systems
for neuroscience and cardiac research, and its strengths are as
follows:
A proprietary CMOS image sensor with high speed, wide dynamic
range, and low noise:
It is designed to detect both voltage-sensitive dye signals and
calcium signals with an optimal S/N ratio.
Over 27 years of experience in developing imaging systems, optics,
and software.
Provides ready-to-use turnkey systems,
with custom products available upon customer request. Hardware
connections are also easy, allowing for immediate data acquisition
after setup.
A proven track record: Their imaging
systems have been used in 650 scientific research papers and 420
units have been installed in over 220 universities, research
institutions, and companies.
