Summary
Single fibre recordings were performed from the auditory nerve of the caiman, Caiman crocodilus. All neurones were spontaneously active (1–80 imp/s). Clicks evoked multiple peaks in the post stimulus time histogram spaced at 1/CF. At high intensities irregularities were observed. The latencies of the first peak observable were intensity-dependent and related to CF. The number of peaks was correlated with tuning properties of the fibre.
Frequency threshold curves were asymmetrical, with low frequency slopes less steep than high frequency slopes. Q10 dB was between 1.5 and 7 with best tuning at high CF. CF ranged from 30 Hz to 2.8 kHz, lowest thresholds down to 5 dB SPL. Intensity functions were nonmonotonic.
In isointensity contours the best frequency shifted downwards with increasing stimulus level. At highest levels a response dip was observed above CF.
Phase locking, two tone suppression and excitability by combination tones were observed.
In comparison to the mammalian cochlea similarities and differences were found.
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References
Anderson, D.J., Rose, J.E., Hind, J.E., Brugge, J.F.: Temporal position of discharges in single auditory nerve fibers within the cycle of a sine-wave stimulus frequency and intensity effects. J. Acoust. Soc. Am. 49, 1131–1139 (1971)
Baird, I.L.: Anatomical features of the inner ear in sub-mammalian vertebrates. In: Handbook of sensory physiology, Vol. V/1, W.D. Keidel, W.D. Neff (eds.), pp. 159–212. Berlin, Heidelberg, New York: Springer 1973
De Boer, E., Kuyper, P.: Triggered correlation. IEEE Transactions on Bio-Med. Engineer. 15, 169–179 (1968)
Dallos, P., Ryan, A., Harris, D., McGee, T., Özdamar, Ö.: Cochlear frequency selectivity in the presence of hair cell damage. In: Psychophysics and physiology of hearing, E.F. Evans, J.P. Wilson (eds.), pp. 249–258. London, New York, San Francisco: Academic Press 1977
Von Düring, M., Karduck, A., Richter, H.-G.: The fine structure of the inner ear in caiman crocodilus. Z. Anat. Entwickl. Gesch. 145, 41–65 (1974)
Durrant, J.D., Dallos, P.: Modification of DIF summating potential components by stimulus biasing. J. Acoust. Soc. Am. 56, 562–570 (1974)
Evans, E.F.: The frequency response and other properties of single fibres in the guinea-pig cochlear nerve. J. Physiol. (Lond.) 226, 263–287 (1972)
Evans, E.F.: The effects of hypoxia on the tuning of single cochlear nerve fibres. J. Physiol. (Lond.) 238, 65–67 P (1974)
Evans, E.F.: Auditory frequency selectivity and the cochlear nerve. In: Facts and models in hearing, Zwicker, E., Terhardt, E. (eds.), pp. 118–129. Heidelberg, Berlin, New York: Springer 1974
Evans, E.F.: Cochlear nerve and cochlear nucleus. In: Handbook of sensory physiology, Vol. V/2, W.D. Keidel, W.D. Neff (eds.), pp. 1–108. Berlin, Heidelberg, New York: Springer 1975
Evans, E.F.: Normal and abnormal functioning of the cochlear nerve. Symp. Zool. Soc. Lond. 37, 133–165 (1975)
Evans, E.F.: Frequency selectivity at high signal levels of single units in cochlear nerve and nucleus. In: Psychophysics and physiology of hearing, E.F. Evans, J.P. Wilson (eds.), pp. 185–192. London, New York, San Francisco: Academic Press 1977
Evans, E.F., Klinke, R.: Reversible effects of cyanide and furosemide on the tuning of single cochlear nerve fibres. J. Physiol. (Lond.) 242, 129P-130P (1974)
Feng, A.S., Narins, P.M., Capranica, R.R.: Three populations of primary auditory fibers in the bullfrog (Rana catesbeiana): Their peripheral origins and frequency sensitivities. J. Comp. Physiol. 100, 221–229 (1975)
Fengler, R., Klinke, R., Pause, M., Smolders, J.: Reverse correlation in primary auditory fibres of the caiman. Pflügers Arch. [Suppl.] 373, R 85 (1978)
Harrison, R.V., Evans, E.F.: The effects of hair cell loss (restricted to outer hair cells) on the threshold and tuning properties of cochlear fibres in the guinea pig. In: Inner ear biology, M. Portmann, J.M. Aran (eds.), Vol. 68, pp. 105–124. Paris: INSERM 1977
Holton, T., Weiss, T.F.: Two-tone rate suppression in lizard cochlear nerve fibers: Relation to auditory receptor morphology. J. Acoust. Soc. Am. 62, 45 (1977)
Kauffmann, G.: Zur Abhängigkeit der Cochleapotentiale des Kaimans vom Stoffwechsel, von aktiven Transporten und von der Temperatur. J. Comp. Physiol. 90, 245–273 (1974)
Kiang, N.Y.S., Baer, T., Marr, E.M., Demont, D.: Discharge rates of single auditory-nerve fibres as functions of tone level. J. Acoust. Soc. Am. 46, 106 (1969)
Kiang, N.Y.S., Liberman, M.C., Baer, T.: Tuning curves of auditory nerve fibres. J. Acoust. Soc. Am. 61, S 27 (1977)
Kiang, N.Y.S., Moxon, E.C.: Physiological considerations in artificial stimulation of the inner ear. Ann. Otol. 81, 714–730 (1972)
Kiang, N.Y.S., Moxon, E.C.: Tails of tuning curves of auditorynerve fibers. J. Acoust. Soc. Am. 55, 620–630 (1974)
Kiang, N.Y.S., Watanabe, T., Thomas, E.C., Clark, L.F.: Discharge patterns of single fibers in the cat's auditory nerve. Research Monograph No. 35, pp. 1–154. Cambridge: MIT Press 1965
Kim, D.O., Molnar, C.E.: A population study of cochlear nerve fibers: comparison of the spatial distributions of average-rate and phaselocking measures of responses to single tones. J. Neurophysiol. 42, 16–30 (1979)
Klinke, R.: Frequency analysis in the inner ear of mammals in comparison to other vertebrates. Verb. Dtsch. Zool. Ges. 1978, pp. 1–15. Stuttgart: Fischer 1978
Klinke, R., Smolders, J.: Effect of temperature shift on tuning properties. Addendum to Klinke, R., Pause, M.: The performance of a primitive hearing organ of the cochlea type: primary fibre studies in the caiman. In: Psychophysics and physiology of hearing, E.F. Evans, J.P. Wilson (eds.), pp. 100–112. London: Academic Press 1977
Liberman, M.Ch.: Auditory-nerve response from cats raised in a low-noise chamber. J. Acoust. Soc. Am. 63, 442–455 (1978)
Lynn, P.A., Sayers, B.McA: Cochlear innervation, signal processing, and their relation to auditory time-intensity effects. J. Acoust. Soc. Am. 47, 525–533 (1970)
Manley, G.A.: Frequency sensitivity of auditory neurons in the caiman cochlear nucleus. Z. Vergl. Physiol. 66, 251–256 (1970)
Manley, G.A.: Activity pattern of neurons in the peripheral auditory system of some reptiles. Brain, Behav. Evol. 10, 244–256 (1974)
Manley, G.A., Robertson, D.: Analysis of spontaneous activity of auditory neurones in the spiral ganglion of the guinea-pig cochlea. J. Physiol. (Lond.) 258, 323–336 (1976)
Moffat, A.J.M., Capranica, R.R.: Effects of temperature on the response properties of auditory nerve fibers on the american toad (bufo americanus). J. Acoust. Soc. Am. 60, 80 (1976)
Peake, W.T., Ling, A.: Absence of tonotopic organization in the motion of the basilar membrane of the alligator lizard. J. Acoust. Soc. Am. 63, P 66 (1978)
Pfeiffer, R.R., Kim, D.O.: Response patterns of single cochlear nerve fibers to click stimuli: descriptions for cat. J. Acoust. Soc. Am. 52, 1669–1677 (1972)
Romahn, G., Boerger, G.: Influence of a low frequency tone on the sensitivity of primary auditory neurons: Two populations. Exp. Brain Res. 32, 423–428 (1978)
Rose, J.E., Hind, J.E., Anderson, D.J., Brugge, J.F.: Some effects of stimulus intensity on response of auditory nerve fibers in the squirrel monkey. J. Neurophysiol. 34, 685–699 (1971)
Russell, I.J., Sellick, P.M.: Intracellular studies of hair cells in the mammalian cochlea. J. Physiol. (Lond.) 284, 261–290 (1978)
Sachs, M.B., Abbas, P.J.: Rate versus level functions for auditory-nerve fibers in cats: tone-burst stimuli. J. Acoust. Soc. Am. 56, 1835–1847 (1974)
Sachs, M.B., Kiang, N.Y.S.: Two-tone inhibition in auditory nerve fibres. J. Acoust. Soc. Am. 43, 1120–1128 (1968)
Schuknecht, H.F.: Neuroanatomical correlates of auditory sensitivity and pitch discrimination in the cat. In: Rassmussen, G.L., Windle, W.F. (eds.), pp. 76–90. Neural mechanisms of the auditory and vestibular systems. Springfield: Thomas 1960
Smith, C.A., Takasaka, T.: Auditory receptor organs of reptiles, birds, and mammals. In: Contributions to sensory physiology, Vol. 5, W.D. Neff (ed.), pp. 129–178. New York, London: Academic Press 1971
Spoendlin, H.: Innervation densities of the cochlea. Acta Oto. Laryngol. 73, 235–248 (1972)
Takasaka, T., Smith, C.: The structure and innervation of the pigeon's basilar papilla. J. Ultrastruct. Res. 35, 20–65 (1971)
Wever, E.G., Vernon, J.: Auditory responses in the spectacled caiman. J. Cell. Comp. Physiol. 50, 333–339 (1957)
Weiss, Th.F., Peake, W.T., Ling, A., Holton, Th.: Which structures determine the frequency selectivity and tonotopic organization of vertebrate nerve fibers? Evidence from the alligator lizard. In: Naunton, R.F., Fernandez, C.; Evoked electrical activity in the auditory system, pp. 91–112. New York: Academic Press 1978
Zwicker, E.: Psychoacoustic equivalent of period histograms. J. Acoust. Soc. Am. 59, 166–175 (1976)
Zwislocki, J.J.: Further indirect evidence for interaction between cochlear inner and outer hair cells. In: Psychophysics and physiology of hearing, E.F. Evans, J.P. Wilson (eds.), pp. 125–135. London, New York, San Francisco: Academic Press 1977
Zwislocki, J.J., Sokolich, W.G.: Neuro-mechanical frequency analysis in the cochlea. In: Facts and models in hearing, E. Zwicker, E. Terhardt (eds.), pp. 107–117. Berlin, Heidelberg, New York: Springer 1974
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Klinke, R., Pause, M. Discharge properties of primary auditory fibres in caiman crocodilus: Comparisons and contrasts to the mammalian auditory nerve. Exp Brain Res 38, 137–150 (1980). https://doi.org/10.1007/BF00236735
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DOI: https://doi.org/10.1007/BF00236735