Summary
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1.
Brainstem auditory evoked potentials (BAEPs) from subcutaneous electrodes were obtained from the megachiropteran echolocating bat,Rousettus aegyptiacus.
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2.
BAEP amplitude was measured as a function of a stimulus frequency. The lowest thresholds (defined as a 1 μV averaged response) lay between 10 and 20 kHz, and responses could be obtained from 5 to 45 kHz in most individuals (Fig. 3). Threshold increased at a rate of 30 dB/octave below 10 kHz and 40 dB/octave above 17 kHz.
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3.
Electrode configuration affected some components of the BAEP waveform (Fig. 1), but not the frequency response of the BAEP (Fig. 3). Pentobarbital anesthesia raised BAEP thresholds at all frequencies tested (Fig. 4), when compared with the unanesthetized state. BAEP thresholds were not affected by changes in deep rectal temperature in the range of 29–30 °C (Fig. 4).
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4.
Comparison of the BAEP frequency response curve with the behavioral audiogram (Fig. 6) suggests that it is an accurate predictor of the region of greatest auditory sensitivity.
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Abbreviations
- BAEP :
-
brainstem auditory evoked potential
- SPL :
-
sound pressure level
References
Achor L, Starr A (1980) Auditory brain stem responses in the cat: I. Intracranial and extracranial recordings. Electroencephalogr Clin Neurophysiol 48:154–173
Begleiter H, Projesz G, Chou CL (1981) Auditory brainstem potentials in chronic alcoholics. Science 211:1064–1066
Brown AM (1973) An investigation of the cochlear microphonic response of two species of echolocating bats:Rousettus aegyptiacus andPipistrellus pipistrellus. J Comp Physiol 83:407–413
Dalland JI (1965) Hearing sensitivity in bats. Science 150:1185–1186
Davis H (1976) Principles of electric response audiometry. Ann Otol Rhinol Laryngol 85:Suppl 28
Gilman AG, Goodman LS, Gilman A (1980) The pharmacological basis of therapeutics, 6th ed. Mammillan, New York
Griffin DR, Novick A, Kornfield N (1958) The sensitivity of echolocation in the fruit bat,Rousettus. Biol Bull 115:107–113
Grinnell AD (1963) The neurophysiology of audition in bats: Intensity and frequency parameters. J Physiol (Lond) 167:38–66
Grinnell AD, Hagiwara S (1972) Studies of auditory neurophysiology in non-echolocating bats, and adaptations for echolocation in one genus,Rousettus. Z Vergl Physiol 76:82–96
Harrison JB (1965) Temperature effects on responses in the auditory system of the little brown bat,Myotis l. lucifugus. Physiol Zool 38:34–48
Jewett DL (1970) Volume-conducted potentials in response to auditory stimuli as detected by averaging in the cat. Electroencephalogr Clin Neurophysiol 28:609–618
Jewett DL, Williston JS (1971) Auditory-evoked far fields averaged from the scalp of humans. Brain 94:681–696
Jones TA, Schorn V, Siu G, Stockard JJ, Rossiter VS, Bickford RJ, Sherbrough FW (1977) Effects of local and systemic cooling on brainstem auditory responses. Electroencephalogr Clin Neurophysiol 43:469–470
Jones TA, Stockard JJ, Weidner WJ (1980) The effects of temperature and acute alcohol intoxication on brain stem auditory evoked potentials in the cat. Electroencephalogr Clin Neurophysiol 49:23–80
Kodera K, Yamane H, Yamada O, Suzuki JI (1977) Brain stem response audiometry at speech frequencies. Audiology 16:469–479
Kuhl W, Schodder GR, Schröder FK (1954) Condenser transmitters and microphones with solid dielectric for airborne ultrasonics. Acustica 4:519–532
Kulzer E (1956) Flughunde erzeugen Orientierungslaute durch Zungenschlag. Naturwissenschaften 43:117–118
Kulzer E (1965) Temperaturregulation bei Fledermäusen (Chiroptera) aus verschiedenen Klimazonen. Z Vergl Physiol 50:1–34
Long GR, Schnitzler H-U (1975) Behavioral audiograms from the bat,Rhinolophus ferrumequinum. J Comp Physiol 100:211–219
Marshall NK, Donchin E (1981) Circadian variation in the latency of brainstem responses and its relation to body temperature. Science 212:356–358
Neuweiler G, Schuller G, Schnitzler H-U (1971) On- and off-responses in the inferior colliculus of the greater horseshoe bat to pure tones. Z Vergl Physiol 74:57–63
Novick A (1958) Orientation in paleotropical bats II. Megachiroptera. J Exp Zool 137:443–459
Pye A (1975) Comparison of histological changes in the cochlea of the guinea pig and the bat,Rousettus, after acoustic trauma. Symp Zool Soc (Lond) 37:97–105
Roberts LH (1975) Confirmation of the echolocation pulse production mechanism ofRousettus. J Mammal 56:218–220
Rothenburg S, Davis H (1967) Auditory evoked response in chinchilla: Application to animal audiometry. Percept Psychophys 2:443–447
Schorn V, Lennon V, Bickford RG (1977) Temperature effects on the brainstem auditory evoked responses (BAER's) of the rat. Proc San Diego Biomed Eng Symp 16:313–318
Simmons JA, Howell DJ, Suga N (1975) Information content of bat sonar echoes. Am Sci 63:204–215
Suthers RA, Summers CA (1980) Behavioral audiogram and masked thresholds of the megachiropteran echolocating bat,Rousettus. J Comp Physiol 108:303–311
Webster WR, Aitkin LM (1971) Evoked potential and single-unit studies of neural mechanisms underlying the effects of repetitive stimulation in the auditory pathway. Electroencephalogr Clin Neurophysiol 31:581–592
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Belknap, D.B., Suthers, R.A. Brainstem auditory evoked responses to tone bursts in the echolocating bat,Rousettus . J. Comp. Physiol. 146, 283–289 (1982). https://doi.org/10.1007/BF00612699
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DOI: https://doi.org/10.1007/BF00612699