The cochlear size of bats and rodents derived from MRI images and histology.
From the evolutionary perspective, the ear of each animal species is built for effective processing of the biologically relevant signals used for communication and acoustically guided orientation. Because the sound pulses used by echolocating bats for orientation and rodents for communication are quite different, the basic design of the mammalian auditory system commonly shared by echolocating bats must be specialized in some manner to effectively process their species-specific sounds. The present study examines the difference in the cochlea of these animal species using MRI images and histological techniques. We report here that, although all these animal species share a similar cochlear structure, they vary in their cochlear size and turns. Bats using constant frequency-frequency-modulated pulses (CF-FM bats) and frequency-modulated pulses (FM bats) for echolocation have a larger cochlear size and more cochlear turns than rodents (mice and rats). However, CF-FM bats have the largest cochlear size and most cochlear turns. This difference in cochlear size and turns of these animal species is discussed in relation to their biologically relevant sounds and acoustic behavior.
aDepartment of Life Science, National Taiwan Normal University, Taipei, Taiwan bCollege of Special Education, Bingzhou Medical College, Yantai, Shangdong, People's Republic of China cDivision of Biological Sciences, University of Missouri, Columbia, Missouri, USA.
Chun Jen
CJ
Hsiao
Philip Hung-Sun
PH
Jen
Chung Hsin
CH
Wu
D000818:Animals; D005075:Biological Evolution; D002685:Chiroptera / Q000033:anatomy & histology*; D003051:Cochlea / Q000033:anatomy & histology* / Q000166:cytology*; D004455:Echolocation / Q000502:physiology; D005260:Female; D006652:Histological Techniques; D008279:Magnetic Resonance Imaging; D051379:Mice / Q000033:anatomy & histology*; D051381:Rats; D017208:Rats, Wistar / Q000033:anatomy & histology*; D013045:Species Specificity