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Vocalization influences auditory processing in collicular neurons of the CF-FM-bat,Rhinolophus ferrumequinum

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Summary

  1. 1.

    In awake Greater Horseshoe bats (Rhinolophus ferrumequinum) the responses of 64 inferior colliculus neurons to electrically elicited vocalizations (VOC) and combinations of these with simulated echoes (AS: pure tones and AS(FM): sinusoidally frequency-modulated tones mimicking echoes from wing beating insects) were recorded.

  2. 2.

    The neurons responding to the species-specific echolocation sound elicited by electrical stimulation of the central grey matter had best frequencies between 76 and 86 kHz. The response patterns to the invariable echolocation sound varied from unit to unit (Fig. 1).

  3. 3.

    In 26 neurons the responses to vocalized echolocation sounds markedly differed from those to identical artificial ones copying the CF-portion of the vocalized sound (AS). These neurons reacted with a different response to the same pure tone whether it was presented artificially or vocalized by the bat (Fig. 2). In these neurons vocalization activities qualitatively alter the responsiveness to the stimulus parameters of the echoes.

  4. 4.

    A few neurons neither responded to vocalization nor to an identical pure tone but discharged when vocalization and pure tone were presented simultaneously.

  5. 5.

    In 2 neurons synchronized encoding of small frequency-modulations of the pure tone (mimicking an echo returning from a wing beating prey) occurred only during vocalization. Without vocalization the neurons did not respond to the identical stimulus set (Fig. 3). In these neurons vocalization activities enhanced FM-encoding capabilities otherwise not present in these neurons.

  6. 6.

    FM-encoding depended on the timing between vocalization and frequency-modulated signal (echo). As soon as vocalization and FM-signal no more overlapped or at least 60–80 ms after onset of vocalization synchronized firing to the FM was lost (4 neurons) (Fig. 4).

  7. 7.

    4 neurons weakly responded to playbacks of the bat's own vocalization 1 ms after onset of vocalization. But when the playback frequency was shifted to higher frequencies by more than 400 Hz the neurons changed firing patterns and the latency of the first response peak (Fig. 5). These neurons sensitive to frequency shifts in the echoes returning during vocalization may be relevant to the Doppler-shift compensation mechanism in Greater Horseshoe bats.

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Abbreviations

AS :

see Summary (1)

AS(FM) :

see Summary (1)

CF :

constant frequency

FM :

frequency modulated

VOC :

electrically elicited vocalization

References

  • Grinnell, A.D.: The neurophysiology of audition in bats: temporal parameters. J. Physiol. (Lond.)167, 67–96 (1963)

    Google Scholar 

  • Harnischfeger, G.: An improved method for extracellular marking of electrode tip positions in nervous tissue. J. Neurosci. Meth. (in press) (1979)

  • Möller, J.: Response characteristics of inferior colliculus neurons of the awake CF-FM-bat,Rhinolophus ferrumequinum. II. Twotone stimulation. J. Comp. Physiol.125, 227–236 (1978)

    Google Scholar 

  • Möller, J., Neuweiler, G., Zöller, H.: Response characteristics of inferior colliculus neurons of the awake CF-FM-bat,Rhinolophus ferrumequinum. I. Single tone stimulation. J. Comp. Physiol.125, 217–225 (1978)

    Google Scholar 

  • Oswald, J.: Die Funktion der Mittelohrmuskulatur bei der Großen Hufeisennase. Diplomarbeit, Frankfurt (1976)

  • Schuller, G.: Echo delay and overlap with emitted orientation sounds and Doppler-shift compensation in the bat,Rhinolophus ferrumequinum. J. Comp. Physiol.114, 103–114 (1977)

    Google Scholar 

  • Schuller, G.: Coding of small sinusoidal frequency and amplitude modulations in the inferior colliculus of “CF-FM” bat,Rhinolophus ferrumequinum. Exp. Brain Res.34, 117–132 (1979)

    Google Scholar 

  • Schuller, G., Beuter, K., Schnitzler, H.-U.: Response to frequency shifted artificial echoes in the batRhinolophus ferrumequinum. J. Comp. Physiol.89, 275–286 (1974)

    Google Scholar 

  • Suga, N., Jen, P.H.-S.: Peripheral control of acoustic signals in the auditory system of echolocating bats. J. Exp. Biol.62, 277–311 (1975)

    Google Scholar 

  • Suga, N., Schlegel, P.: Neural attenuation of responses to emitted sounds in echolocating bats. Science177, 82–84 (1972)

    Google Scholar 

  • Suga, N., Simmons, J.A., Shimozawa, T.: Neurophysiological studies on echolocation systems in awake bats producing CF-FM orientation sounds. J. Exp. Biol.61, 379–399 (1974)

    Google Scholar 

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Supported by Stiftung Volkswagenwerk, Grant No. 111858. Deutsche Forschungsgemeinschaft, Grant No. Br 593/2, Schu 390/1,2

I wish to thank Dr. G. Neuweiler (Universität Frankfurt) and Dr. G. Pollack (University of Austin, Texas) for fruitful discussions and for the valuable help to correct the English version, as well as to Miss N. Chayegan for valuable technical help.

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Schuller, G. Vocalization influences auditory processing in collicular neurons of the CF-FM-bat,Rhinolophus ferrumequinum . J. Comp. Physiol. 132, 39–46 (1979). https://doi.org/10.1007/BF00617730

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