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, 9 (1), 10396

Measuring Vision Using Innate Behaviours in Mice With Intact and Impaired Retina Function

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Measuring Vision Using Innate Behaviours in Mice With Intact and Impaired Retina Function

R Storchi et al. Sci Rep.

Abstract

Measuring vision in rodents is a critical step for understanding vision, improving models of human disease, and developing therapies. Established behavioural tests for perceptual vision, such as the visual water task, rely on learning. The learning process, while effective for sighted animals, can be laborious and stressful in animals with impaired vision, requiring long periods of training. Current tests that that do not require training are based on sub-conscious, reflex responses (e.g. optokinetic nystagmus) that don't require involvement of visual cortex and higher order thalamic nuclei. A potential alternative for measuring vision relies on using visually guided innate defensive responses, such as escape or freeze, that involve cortical and thalamic circuits. In this study we address this possibility in mice with intact and degenerate retinas. We first develop automatic methods to detect behavioural responses based on high dimensional tracking and changepoint detection of behavioural time series. Using those methods, we show that visually guided innate responses can be elicited using parametisable stimuli, and applied to describing the limits of visual acuity in healthy animals and discriminating degrees of visual dysfunction in mouse models of retinal degeneration.

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Behavioural arena, data analyses and experimental protocols. (a) Schematic of the open field arena used for all tests (dimension: 30 × 30 cm). Power LEDs were used to provide diffuse illumination for the flashes while a rear projection screen was used to deliver the looming stimuli. (b) Images of a mouse in the arena (bottom) over successive frames (superimposed pink and green images) during periods of quiescence (left), head movement (middle) and locomotion (right). Landmarks were automatically identified on the mouse’s body (blue dots on images at bottom) and the speed of each landmark calculated as proportional to the change in position from previous frame (visualised as yellow lines). Distribution of speed across landmarks was then calculated for each frame (top panels) and 10th, 30th, 50th, 70th, 90th speed quantiles (respectively Q10 to Q90) used for subsequent analyses. (c) Behavioural time series showing velocity of landmarks (Q10–90) extracted from two cameras (camera 1 and 2, bottom panel; visual stimulus at time 0). Changepoint detection was run independently on each series (single changepoints depicted by black dots) and identified changepoints were then summed for each frame across those series (top panels, “pooled changepoints”) and used for changepoint statistics throughout the study. (d) Schematic of the two stimulation protocols used for full field flash and pattern detection. In both protocols the order of each stimulus is block randomised (note: each block is represented by the list of all the distinct stimuli for that protocol).
Figure 2
Figure 2
Behavioural responses to full field flashes in visually intact animals. (a) Movement responses to dim, mid and bright flashes (respectively left, middle and right panels; visual stimulus at time 0). Each grey line represents a different quantile of the speed distribution (10th, 30th, 50th, 70th, 90th quantiles, respectively Q10 to Q90, averaged across the two cameras used to track behaviour, see also Fig. 1a–c and Methods). (b) Difference between changepoint rate after and before stimulus onset (calculated as Δ#chp/s = #chp/s (pre) - #chp/s (post), see Methods; the rates were calculated in time windows of 0.6 s). (c) Behavioural changepoints for individual trials for mid and bright flashes (respectively left and right panels). For both flashes we collected 84 trials (each trial here reported as row along the y-axis) from 12 animals (7 trials/animal). The flash was delivered at time 0). For a given trial the number of changepoints occurring at the same time frame are colour coded gray-to-black as exemplified in Fig. 1c (“pooled changepoints”). *p < 0.05, **p < 0.0.01, ***p < 0.005, ****p < 0.001, *****p < 0.0005, ******p < 0.0001, ns = not significant.
Figure 3
Figure 3
Behavioural responses to looming + gratings in visually intact animals. (a) Movement responses (in log scale for 10th, 30th, 50th, 70th, 90th quantiles - respectively Q10 to Q90 - averaged across two cameras) to all spatial frequencies tested for the spatial acuity stimulus represented in Fig. 1d (the spatial frequency for each panel is indicated in cycles/degree in the top left corner of each panel; visual stimulus at time 0). Reduction in movement was significant for all frequencies apart from the highest (1.088 cycles/degree). (b) Differences in changepoint rate before and after stimulus onset across all spatial frequencies tested (mean ± sem; spatial frequencies are indicated as cycles/dregrees on the x-axis). (c) Behavioural changepoints for individual trials at different spatial frequencies (0.068, 0.272, 1.088 cycles/degree; 91, 91, 105 trials, 7 trials/animal; visual stimulus delivered at time 0). For a given trial the number of changepoints occurring at the same time frame are colour coded gray-to-black as exemplified in Fig. 1c (“pooled changepoints”). *p < 0.05, **p < 0.01, ***p < 0.005, ****p < 0.001, *****p < 0.0005, ******p < 0.0001, ns = not significant.
Figure 4
Figure 4
Behavioural responses to full field flashes and looming + gratings in mouse models of retinal degeneration. (a) Increase in speed after bright flash for young and old rd1 animals (respectively left and right panels). (b) Immunostaining of retinal wholemounts from “old” cohort of rd1 mice revealed presence of surviving S-cones in peripheral ventral regions. A diagram showing pattern of anti-SWS cone opsin staining in a representative rd1retina (left), with an example micrograph of the anti-SWS cone staining we observed in the ventral retina shown on the right. Asterisk indicates location of micrograph in diagram of the retina. An expanded version of this figure is shown in Supplementary Fig. 7. (c) Behavioural changepoint for individual trials under bright flash stimuli for “young” and “old” animals (respectively left and right panels; 56, 84 trials collected from 8, 12 animals; each animals recorded for 7 trials; visual stimulus at time 0). (d) Increase in changepoint rate (mean ± sem) as function of flash intensity. (e) Looming did not evoke changes in speed in both groups. Speed, represented in log scale, was averaged across the spatial frequencies tested (0.017, 0.068 and 0.272 cycles/degree). (f) Changepoint rates did not significantly change after stimulus onset at all spatial frequencies tested (0.017, 0.068, 0.272 cycles/deg; mean ± sem). (g) rd12 expressed significant reductions in movement at 0.068 cycles/deg (left panel) and at 0.272 cycles/deg (right panel). (h) Behavioural changepoints for individual trials during looming gratings at 0.068 cycles/deg reveals repeatable responses (left). Changepoint rates as function of spatial frequencies (right panel; mean ± sem). *p < 0.05, **p < 0.01, ***p < 0.005, ****p < 0.001, *****p < 0.0005, ******p < 0.0001, ns = not significant.
Figure 5
Figure 5
Behavioural habituation to repeated stimulation in visually intact and retinally degenerate mice. (a) Average changes in speed after stimulus onset as function of trial order for the highest intensity flash (data shown as mean ± sem). Represented in left and right panels are visually intact and “young” rd1 animals. Both groups exhibit a negative trend (visually intact: p = 0.049, n = 36 trials; young rd1: p = 0.039; n = 24 trials; comparisons between early and late trials, permutation test). (b) Difference between changepoint rate after and before stimulus onset (Δ#chp/s) as function of trial order during highest intensity flash for visually intact and young rd1 animals (respectively left and right panel). Neither group showed a significant trend (visually intact: p = 0.718, n = 36 trials; young rd1: p = 0.283; n = 24 trials; comparisons between early and late trials, ranksum test). (c,d) Like panels a and b but for looming responses in visually intact and rd12 animals. No significant trend was observed for visually intact animals (panel c: p = 0.482, n = 39 trials; panel d: p = 0.556, n = 39 trials). The rd12 groups exhibited gradual reduction in speed (p = 0.001, n = 21 trials) while no clear trend could be observed in changepoints (p = 0.401, n = 21 trials). (e) Alternative protocol based on systematic reduction of spatial frequency from highest to lowest (1.088, 0.544, 0.272, 0.136, 0.068, 0.034, 0.017 cycles/degree). Each spatial frequency was presented only on one trial and repeated three times (each repetition lasting 660 ms as previous tests reported in Fig. 1d; double arrows represent this time interval) during that trial as in. (f) Average speed response for all spatial frequencies tested (n = 5 animals, 1 trial/animal). (g) Polynomial fit for changes in speed as function of spatial frequency (polynomial degree = 2; R2 = 0.263; same dataset shown in from panel f, data shown as mean ± sem). Consistent with results obtained by using the block randomised protocol (Fig. 3a–c) reduction in speed can be observed up to 0.544 cycles/degrees but not at 1.088 cycles/degrees.

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References

    1. Chang B, et al. Mouse models of ocular diseases. Visual Neurosci. 2005;22(5):587–593. doi: 10.1017/S0952523805225075. - DOI - PubMed
    1. Busskamp V, Picaud S, Sahel JA, Roska B. Optogenetic therapy for retinitis pigmentosa. Gene Ther. 2012;19(2):169–175. doi: 10.1038/gt.2011.155. - DOI - PubMed
    1. Auricchio A, Smith AJ, Ali RR. The Future Looks Brighter After 25 Years of Retinal Gene Therapy. Hum Gene Ther. 2017;28(11):982–987. doi: 10.1089/hum.2017.164. - DOI - PubMed
    1. Takahashi VKL, Takiuti JT, Jauregui R, Tsang SH. Gene therapy in inherited retinal degenerative diseases, a review. Ophthalmic genetics. 2018;39(5):560–568. doi: 10.1080/13816810.2018.1495745. - DOI - PubMed
    1. Lagali PS, et al. Light-activated channels targeted to ON bipolar cells restore visual function in retinal degeneration. Nat Neurosci. 2008;11(6):667–675. doi: 10.1038/nn.2117. - DOI - PubMed

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