Biomaterial Database

Binaural acoustic reflex activity following monaural noise exposure in decerebrate chinchillas. 1986

K J Gerhardt, and J P Walton

Acoustic reflex thresholds, latencies and magnitudes were recorded binaurally in decerebrate chinchillas suffering monaural, temporary noise trauma. Simultaneous recordings of cochlear microphonics from both cochleae during monaural reflex stimulation served as an index for acoustic reflex dynamics. Baseline values of threshold, latency and magnitude were recorded from ipsilateral and contralateral ears prior to a monaural 2-hour exposure to a 0.5-kHz octave-band noise at 100 dB SPL. Reflex dynamics were measured immediately after exposure and again following 1 h of recovery. Cochlear microphonic input-output functions for the exposed ear were completed prior to and after cessation of the noise and after 1 h of recovery. Acoustic reflex threshold and magnitude increased and latency decreased following exposure to noise for both the ipsilateral and contralateral recording conditions. Reflex activity in the nonexposed ear was unaffected. Reflex properties returned to pre-exposure values following recovery. These responses followed the same time course as changes in cochlear sensitivity. Alterations in reflex response following noise exposure is caused by changes at purely peripheral sites.

UI	MeSH Term	Description	Entries
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D012022	Reflex, Acoustic	Intra-aural contraction of tensor tympani and stapedius in response to sound.	Acoustic Reflex
D002682	Chinchilla	A genus of the family Chinchillidae which consists of three species: C. brevicaudata, C. lanigera, and C. villidera. They are used extensively in biomedical research.	Chinchillas
D003055	Cochlear Microphonic Potentials	The electric response of the cochlear hair cells to acoustic stimulation.	Cochlear Microphonic Potential,Potential, Cochlear Microphonic,Potentials, Cochlear Microphonic
D003655	Decerebrate State	A condition characterized by abnormal posturing of the limbs that is associated with injury to the brainstem. This may occur as a clinical manifestation or induced experimentally in animals. The extensor reflexes are exaggerated leading to rigid extension of the limbs accompanied by hyperreflexia and opisthotonus. This condition is usually caused by lesions which occur in the region of the brainstem that lies between the red nuclei and the vestibular nuclei. In contrast, decorticate rigidity is characterized by flexion of the elbows and wrists with extension of the legs and feet. The causative lesion for this condition is located above the red nuclei and usually consists of diffuse cerebral damage. (From Adams et al., Principles of Neurology, 6th ed, p358)	Decerebrate Posturing,Decorticate Rigidity,Decorticate State,Rigidity, Decerebrate,Rigidity, Decorticate,Decerebrate Posturings,Decerebrate Rigidity,Decerebrate States,Decorticate Rigidities,Decorticate States,Posturing, Decerebrate,Posturings, Decerebrate,Rigidities, Decorticate,State, Decerebrate,States, Decerebrate
D006317	Hearing Loss, Noise-Induced	Hearing loss due to exposure to explosive loud noise or chronic exposure to sound level greater than 85 dB. The hearing loss is often in the frequency range 4000-6000 hertz.	Acoustic Trauma,Hearing Loss, Noise Induced,Noise-Induced Hearing Loss
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
D001309	Auditory Threshold	The audibility limit of discriminating sound intensity and pitch.	Auditory Thresholds,Threshold, Auditory,Thresholds, Auditory