Biomaterial Database

Specializations for sharp tuning in the mustached bat: the tectorial membrane and spiral limbus. 1991

M M Henson, and O W Henson

Department of Surgery, University of North Carolina, Chapel Hill 27599.

The sense of hearing in the mustached bat, Pteronotus parnellii, is specialized for fine frequency analysis in three narrow bands that correspond to approx 30, 60 and 90 kHz constant frequency harmonics in the biosonar signals used for Doppler-shift compensation and acoustic imaging of the environment. Previous studies have identified anatomical specializations in and around the area of the cochlea that processes the dominant second harmonic component, but similar features have not been found in areas related to sharp tuning and high sensitivity for the first or third harmonics. In this report we call attention to the large size of the tectorial membrane and spiral limbus in all three areas that appear to process the harmonically related constant frequency components. These structures are especially pronounced in the regions of the cochlea that respond to the approx 61 kHz, second harmonic and 91.5 kHz, third harmonic bands; they correspond specifically to areas where the density of afferent nerve fibers is high and where very sharply tuned neurons occur. These data for cochleae with multiple specializations lend strong support to the idea that the mass of the tectorial membrane can be an important factor in establishing the response properties of the cochlea.

UI	MeSH Term	Description	Entries
D002685	Chiroptera	Order of mammals whose members are adapted for flight. It includes bats, flying foxes, and fruit bats.	Bats,Flying Foxes,Horseshoe Bats,Pteropodidae,Pteropus,Rhinolophus,Rousettus,Bat, Horseshoe,Bats, Horseshoe,Foxes, Flying,Horseshoe Bat
D003051	Cochlea	The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH.	Cochleas
D004455	Echolocation	An auditory orientation mechanism involving the emission of high frequency sounds which are reflected back to the emitter (animal).	Echolocations
D006309	Hearing	The ability or act of sensing and transducing ACOUSTIC STIMULATION to the CENTRAL NERVOUS SYSTEM. It is also called audition.	Audition
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001489	Basilar Membrane	A basement membrane in the cochlea that supports the hair cells of the ORGAN OF CORTI, consisting keratin-like fibrils. It stretches from the SPIRAL LAMINA to the basilar crest. The movement of fluid in the cochlea, induced by sound, causes displacement of the basilar membrane and subsequent stimulation of the attached hair cells which transform the mechanical signal into neural activity.	Basilar Membranes,Membrane, Basilar,Membranes, Basilar
D001696	Biomechanical Phenomena	The properties, processes, and behavior of biological systems under the action of mechanical forces.	Biomechanics,Kinematics,Biomechanic Phenomena,Mechanobiological Phenomena,Biomechanic,Biomechanic Phenomenas,Phenomena, Biomechanic,Phenomena, Biomechanical,Phenomena, Mechanobiological,Phenomenas, Biomechanic
D013680	Tectorial Membrane	A membrane, attached to the bony SPIRAL LAMINA, overlying and coupling with the hair cells of the ORGAN OF CORTI in the inner ear. It is a glycoprotein-rich keratin-like layer containing fibrils embedded in a dense amorphous substance.	Membrane, Tectorial,Membranes, Tectorial,Tectorial Membranes
D014465	Ultrasonics	A subfield of acoustics dealing in the radio frequency range higher than acoustic SOUND waves (approximately above 20 kilohertz). Ultrasonic radiation is used therapeutically (DIATHERMY and ULTRASONIC THERAPY) to generate HEAT and to selectively destroy tissues. It is also used in diagnostics, for example, ULTRASONOGRAPHY; ECHOENCEPHALOGRAPHY; and ECHOCARDIOGRAPHY, to visually display echoes received from irradiated tissues.	Ultrasonic