The Avian Onboard Flight Computer Traced Back to Archaeopteryx

Monday, April 4, 2016

Study of brain activity in flying birds, published in Current Biology, adds new insight to the evolution of the avian flight-ready brain

Paul M. Gignac, Ph.D., assistant professor of Anatomy and Vertebrate Paleontology in the Department of Anatomical and Cell Biology at Oklahoma State University Center for Health Sciences, and colleagues in New York and Turkey have identified which parts of its brain a bird uses during flight.

The study, published today, revealed that one of the most active brain regions in flying birds is a structure called the Wulst—a distinct bump on the top of the forebrain in modern birds that has long been thought to integrate sensations from body surfaces and feathers with the visual system.

The study, reported online in Current Biology, points out that the Wulst can be identified as an impression left in the braincases of fossil birds, such as Archaeopteryx, allowing the research team to trace the likely origin of an expanded Wulst used for flight to the first bird.

In “Flying starlings, PET and the evolution of volant dinosaurs” the researchers detail their examination of the avian brain using cutting edge 3-D imaging tools like Positron Emission Tomography (PET). Led by Paleoneuroanatomist Eugenia Gold, Ph.D., instructor of Research at Stony Brook University, the study required a broad range of specialties in bird behavior, miniaturization engineering, brain imaging and dinosaur paleontology.

“Flight was a complex behavior for birds to achieve and figuring out how that happened is a difficult problem for scientists to solve. Understanding how evolution modified the reptile brain into an onboard flight computer is a major part of that transformation, and with this research we can now project the functional neuroanatomy of modern birds deep into their fossil record,” said Gignac.

The team merged heat maps of brain activity from European starlings with 3-D maps of the animals’ brains developed using a new technique that differentiates the brain’s white and gray matter in micro-CT images, called diceCT. When paired, PET and diceCT allow for internally visualizing the anatomy of the brain alongside its activity patterns so that the recruitment of neural networks can be seen.

This study represents the first time scientists have ever peered into a bird’s brain during flight, but the team continues to examine other aspects of how birds use their brains for many other behaviors.

“For their size, birds are as brainy as mammals,” said Gignac. “Our long-term goal is to understand the uniquely organized avian brain as a different way for evolution to achieve such high cognition.”

The research was funded by the National Science Foundation.