Biomaterial Database

Steady-state sinusoidal velocity responses of the basilar membrane in guinea pig. 1996

A L Nuttall, and D F Dolan

Kresge Hearing Research Institute, The University of Michigan, Arbor, USA.

This report provides a detailed analysis of tone-evoked velocity responses of basilar membrane (BM) motion measured in the basal turn of the guinea pig cochlea. A laser Doppler vibrometer, coupled to a compound microscope, measured the velocity of reflective microbeads placed onto the scala tympani surface of the BM. The velocity responses of the stapes footplate were also determined, allowing the calculation of a BM transfer function. The normal transfer function is compared to that seen with cochlear "insensitivity" and postmortem. This comparison results in measures of the active process contribution to the magnitude and phase of the BM transfer function. It was found that the active process contributed as much as 65 dB of "gain" and 270 degrees of phase lag at the best frequency. Other details about features of input/output velocity functions and the derived mechanical frequency-tuning curve at a criterion of 50 micron/s are analyzed.

UI	MeSH Term	Description	Entries
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000162	Acoustics	The branch of physics that deals with sound and sound waves. In medicine it is often applied in procedures in speech and hearing studies. With regard to the environment, it refers to the characteristics of a room, auditorium, theatre, building, etc. that determines the audibility or fidelity of sounds in it. (From Random House Unabridged Dictionary, 2d ed)	Acoustic
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
D013199	Stapes	One of the three ossicles of the middle ear. It transmits sound vibrations from the INCUS to the internal ear (Ear, Internal see LABYRINTH).