Scientists at the University of California, Berkeley, have discovered that light-sensitive cells in the developing retina for unborn babies interact with each other, meaning that babies in the womb can see more than previously thought.
A study on mice and monkeys showed that ganglion cells communicate with each other through gap junctions, which allow electrical impulses to pass between cells. Ganglion cells are a type of neuron found in the retina. They begin to develop between weeks five and 18 of pregnancy and around three percent are light-sensitive. Some subtypes regulate circadian rhythms, help constrict the pupils, and influence emotions.
The study showed that gap junctions can influence light responses in a developing retina, suggesting that a developing retina is more complex than previously thought.
"We thought [mouse pups and the human fetus] were blind at this point in development. We thought that the ganglion cells were there in the developing eye, that they are connected to the brain, but that they were not really connected to much of the rest of the retina, at that point," said Marla Feller, a UC Berkeley professor of molecular and cell biology and the senior author of the paper concerning research into embryonic retinal development. "Now, it turns out they are connected to each other, which was a surprising thing."