Biomedical Engineering Reference
In-Depth Information
Camera
Transparent OMR channels
Four-frame movie display
Fish
Direction of movie
Monitor playing striped movie
Cross section of channel
Figure 15.2 Schematic of the OMR apparatus, viewed from above and in cross section. Larvae at 8dpf
swim in transparent channels on a flat screen monitor playing a movie with a high-contrast black and white
grating (bandwidth: 2 cm; drift speed: 1 cycle/s). The movie is played for 45 s in the forward and reverse
directions three times and the position of each larva is recorded by digital photography. (Reprinted from
Richards et al. (2008) with permission from Elsevier.)
0.5 C with compound replenishment at 6dpf. The larvae are then transferred
to a transparent, multi-lane acrylic block containing embryo medium, with 10 larvae
per lane and with two groups of vehicle controls in each assay. The experimental
apparatus for assessingOMR is shown in a schematic representation in Fig. 15.2. OMR
is assessed by subjecting the larvae to a movie played with a high-contrast black and
white grating on a horizontal screen underneath the transparent channels that contained
the larvae. The larvae are shown the movie such that the stripes pass in the forward and
reverse directions three times for 45 s each. The position of each larva in relation to the
end of the channel is then recorded. Larvae with normal vision swim in the direction of
the moving grating toward the end of the channel. At the end of each run, the number of
larvae in the “pass area,”which represents the furthest 25%of the channel, is calculated
and themean percentage in the pass area for all six runs obtained. If either of the vehicle
controls scored < 60% overall,
at 28.5
then the assay is considered invalid (Richards
et al., 2008).
15.3.1.2 OMR Validation Studies Richards et al. (2008) assessed
compounds that cause adverse effects on visual function by a variety of different
mechanisms in a zebrafish OMR assay. This study reported the results of the blinded
testing of 27 compounds, and revealed a good concordance between the effects of
 
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