With video on bride search
How does a horseshoe crab choose its mating partner? When it comes to a computer model that simulates how the neurons of a crab's eye react to different objects, then this question has to be answered: It's all about the right movements. Every spring, male horseshoe crabs prowl the shallows of the ocean in search of mates ready to mate. As with all animals, they do not simply passively take in their entire environment through their eyes, but rather emphasize information important to survival. This can happen, for example, by inhibiting individual neurons in the retina. Studies of individual optical neurons have shown that many animal species can perceive contrasts better as a result. This increases their ability to distinguish possible prey from a background.
But since Robert Barlow, no one has been able to observe the activity of a network of optic neurons in their entirety. Barlow works as a neurobiologist at the Marine Biological Laboratory and at the State University of New York He alth Science Center, Syracuse. He and his colleagues simulated the neural network by creating a computer model of the crab's eye. Now, in the November issue of the Proceedings of the National Academy of Sciences, neural imaging shows what crabs see in their minds when they are looking for a partner.
The computer model imitates the path of the nerve signals from the light receptors of the eye via the approx. thousand optical nerves to the brain of the cancer. The study was made possible by using a so-called CrabCam. This is a mini video camera attached to the crabs' backs. In addition, a single neuron from the crab eye was connected to it. In this way, the activity of the test animal could be recorded while it was moving in its underwater habitat.
In the laboratory, the camera recordings were digitized and used to feed a computer with the relevant data. This calculated the likely activity of hundreds of neurons and produced a series of snapshots that the researchers believe represent the neuronal images that a cancer will ultimately see in front of it. The correspondence between the calculated activities of neurons and the actual behavior of a single neuron was 75% or more in field experiments. Under laboratory conditions even 95% and more were reached.
But what strikes Barlow as particularly interesting is that crayfish's eyes are best equipped to find objects the size of crabs and moving at the appropriate speed, while ignoring motionless objects. So few chances for sleeping beauties!