New York (PTI): Scientists have spent decades probing the origins of depression, schizophrenia and insomnia. Now, a team at Oklahoma Medical Research Foundation claims to have unravelled some key insights into the causes of these common conditions by examining an unlikely research subject -- worms.

In their study, researchers, led by Kenneth Miller, examined the method eye-less microscopic worms known as C. elegans shy away from certain kinds of light. They made several key findings, the key being that exposing paralysed C. elegans to ultraviolet light restored normal levels of movement in the worms, the 'PLoS Biology' journal reported in its latest edition.

In fact, the research team traced the light reaction to a tiny molecular sensor, which is encoded by a gene they named LITE-1. "This sensor doesn't resemble any other light sensors previously discovered," Miller said.

According to the researchers, although humans lack this ultraviolet light sensor, the discovery provides a window for understanding how the molecular signals in the nerve cells allow them to talk to each other to produce perceptions, behaviours, learning and memory.

"That doesn't mean shining an ultraviolet light on people in wheelchairs will suddenly allow them to walk. But it does give us a tool that we can use to solve the mysteries of nerve cell communication and can ultimately help us understand the biology of everything from sleep, memory to depression," Miller said.

Added Michael Koelle of Yale University: "The work has identified a new way that organisms can sense light, distinct from previously known light-sensing mechanism used in the eye. It will be interesting to see whether the LITE-1 mechanism will lead to insights into human sensory perception."