Bats have adapted to life without light by using echolocation to determine obstacles in their path. New research suggests a spatial map in the bat's brain representing different echo delays dynamically adapts to external factors.
When a bat flies to close to an obstacle the numbers of activated neurons in its brain increases, making the object appear larger on the bat's brain map than it actually is, Technische Universität München (TUM) reported.
"The map is similar to the navigation systems used in cars in that it shows bats the terrain in which they are moving," said study director Uwe Firzlaff at the TUM Chair of Zoology. "The major difference, however, is that the bat's in-built system warns them of an impending collision by enhancing neuronal signals for objects that are in close proximity."
Bats are constantly adapting their flight maneuvers to their surroundings in order to avoid colliding with obstacles such as trees and other animals. The ability to determine lateral distance to other objects is extremely important. In order to achieve this bats process more spatial information than echo delays.
"Bats evaluate their own motion and map it against the lateral distance to objects," Firzlaff said.
Bats also process the reflection angle of echoes as well as compare the sound volume of their calls with the reflected sound waves; they measure the spectrum of echo.
"Our research has led us to conclude that bats display much more spatial information on their acoustic maps than just echo reflection," Firzlaff said.
The researchers found nerve cells "interpret the bats' rapid responses to external stimuli by enlarging the active area in the brain to display important information," Technische Universität München reported.
"We may have just uncovered one of the fundamental mechanisms that enables vertebrates to adapt flexibly to continuously changing environments," Firzlaff concluded.
The findings were published in a recent edition of Nature Communications.
