Wheel running behavior is impaired by both surgical section and genetic absence of the mouse corpus callosum. Brain Research Bulletin. 2002; 57:27–33.10.1016/ s0361-9230(01)00633-5 [PubMed: 11827734

These results are not totally conclusive because the strains in question also show a number of behavioral peculiarities that are unrelated to the effects of an absent CC The literature on humans lacking the CC points to mild, language-related deficits in intelligence and rhyming The interpretation of behavioral test results from acallosal mice is challenging because usually no compelling reason exists to believe that the behaviors in question rely heavily on interhemispheric communication. It is also possible that as with human CC agenesi

Preferences for achromatic horizontal, vertical, and square patterns in zebrafish (Danio rerio)

The zebrafish (Danio rerio) is gaining popularity as a laboratory organism and is used to model many human diseases. Many behavioural measures of locomotion and cognition have been developed that involve the processing of visual stimuli. However, the innate preference for vertical and horizontal stripes in zebrafish is unknown. We tested the preference of adult zebrafish for three achromatic patterns (vertical stripes, horizontal stripes, and squares) at three different size conditions (1, 5, and 10 mm). Each animal was tested once in a rectangular arena, which had a different pattern of the same size condition on the walls of either half of the arena. We show that zebrafish have differential preferences for patterned stimuli at each of the three size conditions. These results suggest that zebrafish have naïve preferences that should be carefully considered when testing zebrafish in paradigms using visual stimuli

Scototaxis arena and ethanol administration schedule used with control, weekly-binge, and daily-moderate groups.

<p>(A) The scototaxis arena measured 9.5 cm wide, 9.5 cm deep, and 55 cm long, with black walls covering one half of the arena, white walls covering the other half, and white flooring throughout; water depth was maintained at 5 cm. (B) Ethanol administration and testing took place over a 30 day period. The daily-moderate group (•) received ethanol (0.2%) each day for 21 days of the exposure period, whereas the weekly-binge group (<b>○</b>) received ethanol (1.4%) only on the 7th, 14th and 21st days. All groups, including control, underwent the same daily procedures with the exception of ethanol administration. All animals were tested (T) on days 23 (2^nd day of withdrawal) and 30 (9^th day of withdrawal).</p

Establishing zebrafish as a model to study the anxiolytic effects of scopolamine.

Scopolamine (hyoscine) is a muscarinic acetylcholine receptor antagonist that has traditionally been used to treat motion sickness in humans. However, studies investigating depressed and bipolar populations have found that scopolamine is also effective at reducing depression and anxiety symptoms. The potential anxiety-reducing (anxiolytic) effects of scopolamine could have great clinical implications for humans; however, rats and mice administered scopolamine showed increased anxiety in standard behavioural tests. This is in direct contrast to findings in humans, and complicates studies to elucidate the specific mechanisms of scopolamine action. The aim of this study was to assess the suitability of zebrafish as a model system to test anxiety-like compounds using scopolamine. Similar to humans, scopolamine acted as an anxiolytic in individual behavioural tests (novel approach test and novel tank diving test). The anxiolytic effect of scopolamine was dose dependent and biphasic, reaching maximum effect at 800 µM. Scopolamine (800 µM) also had an anxiolytic effect in a group behavioural test, as it significantly decreased their tendency to shoal. These results establish zebrafish as a model organism for studying the anxiolytic effects of scopolamine, its mechanisms of action and side effects

Dark preference and zone transitions after nine days of withdrawal.

<p>(A) The preference index was calculated as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063319#pone-0063319-g003" target="_blank">Figure 3</a>. No group showed a significant preference for light versus dark. There were no significant differences between groups (One way ANOVA, F (2, 39) <i>p</i> = 0.5487; n = 15 for control, n = 12 for weekly-binge, n = 15 for daily-moderate). (B) The number of zone transitions were calculated as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063319#pone-0063319-g003" target="_blank">Figure 3</a>. There were no significant differences in number of zone transitions between groups nine days after ethanol exposure. (One way ANOVA, F (2,39) = 1.592, <i>p = </i>0.2164; n = 15 for control, n = 12 for weekly-binge, n = 15 for daily-moderate).</p

Naive preference for light/dark zones with and without a black floor.

<p>(A) When a black floor was used, zebrafish spent more time in the dark zone (186.9±11.16 sec, n = 20) compared to the light zone (113.1±11.16 sec, n = 20). (B) With a white floor, the fish also spent more time in the dark zone (207.8±15.37 sec, n = 12) compared to the light zone (92.22±15.37 sec, n = 12). ***<i>p</i><0.001, paired <i>t</i>-test.</p

Establishing zebrafish as a model to study the anxiolytic effects of scopolamine.

Scopolamine (hyoscine) is a muscarinic acetylcholine receptor antagonist that has traditionally been used to treat motion sickness in humans. However, studies investigating depressed and bipolar populations have found that scopolamine is also effective at reducing depression and anxiety symptoms. The potential anxiety-reducing (anxiolytic) effects of scopolamine could have great clinical implications for humans; however, rats and mice administered scopolamine showed increased anxiety in standard behavioural tests. This is in direct contrast to findings in humans, and complicates studies to elucidate the specific mechanisms of scopolamine action. The aim of this study was to assess the suitability of zebrafish as a model system to test anxiety-like compounds using scopolamine. Similar to humans, scopolamine acted as an anxiolytic in individual behavioural tests (novel approach test and novel tank diving test). The anxiolytic effect of scopolamine was dose dependent and biphasic, reaching maximum effect at 800 µM. Scopolamine (800 µM) also had an anxiolytic effect in a group behavioural test, as it significantly decreased their tendency to shoal. These results establish zebrafish as a model organism for studying the anxiolytic effects of scopolamine, its mechanisms of action and side effects