The scientists, from Yale University along with experts from China and Brazil, found that when they turned the light off, the mice went back to normal. “What is interesting about predatory behavior is that it is not just one type of movement, it involves locomotors and craniofacial movements”. “We put a thin optic fiber into the head of the animal”, said de Araujo, and “in turn connected [it] to a blue laser source”.
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Researchers were specifically trying to learn about various animals’ feeding behaviors, the neural functions related to those behaviors, and how the biology of each has evolved over the centuries. “Perhaps more strikingly, when we used a bug made of plastic, we could make the animals pursue an object that they would normally avoid”.
However, the mice reserve their newfound aggression for prey, never attacking each other in the experiments. These results offer a glimpse into how the brain changed hundreds of millions of years ago when jaws first developed.
The central amygdala also appears to be a primary component of what forces an animal to initiate prey pursuit, which includes stalking, running towards prey, and fight or freeze behaviors. This instinct played a big part in the evolution of the brain. Some of them scampered around their cages to hide from prey or to avoid looking at toys which might seem like a prey for them. Although they continued to attack anything placed in their path, be it cricket or a hunk of plastic, the scientists did not witness any attacks on other mice. “I began to wonder how natural and relevant this behavior is”.
“Understanding how the brain controls predatory hunting would provide us with a much better grasp on how the brain coherently links sensory perception with motor output; the so-called “sensorimotor integration” problem”, he told WIRED.
While they found many regions that dealt with each, only the central nucleus of the amygdala responded nearly exclusively to hunting. They start attacking and biting nearly anything they can find, from bottle caps to wood sticks. When they blocked the neurons responsible for prey pursuit, the mice were slow to chase but still able to bite. The research team focused on the hunting region, which was located in the central nucleus of the amygdala.
The scientists identified two neurons in the rodent’s brain, one which controlled hunting and the other which led to biting.
‘We now have a grip on their anatomical identities, so we hope we can manipulate them even more precisely in the future, ‘ he said.
The researchers tested two separate regions involved in hunting, one linked with pursuing prey and another linked with biting. “They fail to deliver the killing bite”.
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Previous work has shown that hunting activates cells in the rat amygdala.
