How birds detect the Earth’s magnetic field
April 30, 2012
Researchers at Baylor College of Medicine (BCM) have found that vestibular neurons in the brain are part of the receptor network that detects and sends information about the direction and intensity of the Earth’s magnetic field to the rest of the brain.
“We know birds and many other animals can sense the magnetic force; behavioral studies show that birds fly along magnetic routes during seasonal changes,” said J. David Dickman, BCM professor of neuroscience, who conducted much of the research at Washington University in St. Louis.
“It is still unknown what exactly acts as a receptor within the bird; however, in our current study we are able to show how neurons in the pigeon’s brain encode magnetic field direction and intensity. This is how we believe birds know their position on the surface of the Earth.”
Dickman said certain areas of the brain are activated when a particular area of the inner ear, known as the lagena, is exposed to a magnetic field. Without it, several of these corresponding areas in the brain show no activity.
“The cells responded to the angle and intensity of the magnetic field. Some cells were more sensitive depending on what direction we aimed the magnetic field around the bird’s head,” Dickman said.
“Birds give us a unique opportunity to study how the brain develops these spatial maps and the receptors that feed into it because they have such a great ability to navigate,” he said. “Birds actually have more similarities to the human brain than not, so understanding these characteristics could eventually lend itself to understanding how we create spatial maps and those disorders that affect these areas of the brain.”
Ref.: Le-Qing Wu, J. David Dickman, Neural Correlates of a Magnetic Sense, Science, 2012, DOI: 10.1126/science.1216567