\n I<\/p>\n
n the new study, zebrafish larvae lived in V-shaped channels with either horizontal or vertical black and white stripes on the walls for the first five days after fertilization.<\/p>\n
Amacrine cells oriented parallel to the stripes became more elongated than usual, while others became rounder. Since these cells are distributed evenly across the retina, shape changes suggest that some occupy more space than others, says study investigator Phoebe Reynolds<\/a>, postdoctoral fellow at the Friedrich Miescher Institute for Biomedical Research.<\/p>\n At this stage, orientation-selective retinal output to the optic tectum was biased towards the stripe orientation the fish saw, the researchers found, and the bias persisted for at least two days after the animals were moved to a neutral environment.<\/p>\n \n The field in general doesn\u2019t think that activity has any effect on the retina, and it\u2019s always [acting] downstream. <\/p>\n \u2014 <\/p>\n \u2014 In another series of experiments, freely swimming fish given a choice between stripes of different angles preferred swimming towards stripes that ran parallel to their bodies, but those raised in a horizontal environment showed no preference. Fish lacking the TENEURIN-3 gene and raised in a horizontal environment, however, behaved normally, which suggests the animals can see the stimuli, but the loss of the gene \u201cdisturbs the cells in a way that they lose the ability to show plasticity,\u201d Hindges says.<\/p>\n It is unclear why only the zebrafish raised in a vertical stripe environment prefer parallel-oriented stripes, he says. In addition to exploring the behavior further, Hindges says he is interested in looking at how \u201cthe changed amacrine cells\u201d connect differently to ganglion cells.<\/p>\n
\n Marla Feller <\/p>\n