Advertisement

Chinese Science Bulletin

, Volume 49, Issue 10, pp 1026–1031 | Cite as

Role of frequency band integration in sharpening frequency tunings of the inferior colliculus neurons in the big brown bat,Eptesicus fuscus

  • Feijian Wu
  • Qicai Chen
  • Philip H. S. Jen
  • Junxian Shen
Articles

Abstract

By means of a particular two-tone stimulation paradigm in combination of using a pair of electrodes for simultaneously recording from two inferior colliculus (IC) neurons, the currentin vivo study is undertaken to explore the role of frequency band integration (FBI) in sharpening of frequency tuning in the big brown bat,Eptesicus fuscus. Three major results are found: (1) The paired neurons correlated to FBI are located not only within the same frequency filter bandwidth (FFB), but also across different FFBs. The relations of their frequency tuning curves (FTCs) are mainly of two types: the flank-overlapped and overlaid patterns. (2) Although the sharpness of FTCs between paired neurons is mutual, the sharpening efficiency of neurons located within the same FFB is higher than that of neurons across FFBs, and the FTCs of neurons with the best frequencies (BF) of 20 –30 kHz are most strongly sharpened. (3) The strength of FBI is weak near the BF but gradually increased with frequencies away from the BF of sound stimuli. This suggests that the dynamical FBI of the IC neurons located within and across the FFBs might be involved in the formation of functional FFB structures.

Keywords

frequency band integration frequency tuning sharpen inferior colliculus bat 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Schreiner, C. E., Langner, G., Laminar fine structure of frequency organization in auditory midbrain, Nature, 1997, 388: 383–386.CrossRefGoogle Scholar
  2. 2.
    Lu, Y., Jen, P. H. S., GABAergic and glycinergic neural inhibition in excitatory frequency tuning of bat inferior collicular neurons, Exp. Brain Res., 2001, 141: 331–339.CrossRefGoogle Scholar
  3. 3.
    Yang, L. C., Pollk, G. D., Resler, C., GABAergic circuits sharpen tuning curves and modify response properties in the mustache bat inferior colliculus, J. Neurophysiol., 1992, 68: 1760–1774.Google Scholar
  4. 4.
    Malmierca, M. S., Rees, A., LeBeau, F. E. N. et al., Laminar or- ganization of frequency defined local axons within and between the inferior colliculus of the guinea pig, J. Comp. Neurol., 1995, 357: 124–144.CrossRefGoogle Scholar
  5. 5.
    Reets, G., Ehret, G., Inputs from three brainstem sources to identi- fied neurons of the mouse inferior colliculus slice, Brain Res., 1999, 816: 527–543.CrossRefGoogle Scholar
  6. 6.
    Mazer, J. A., How the owl resolves auditory coding ambiguity, Proc. Natl.Acad. Sci. USA, 1998, 95: 10932–10937.CrossRefGoogle Scholar
  7. 7.
    Schreiner, C. E., Read, H. L., Sutter, M. L., Modular organization of frequency integration in primary auditory cortex, Annu. Rev. Neurosci., 2000, 23: 501–529.CrossRefGoogle Scholar
  8. 8.
    Kadia, S. C., Wang, X., Spectral integration in Al of awake pri- mates: neurons with single- and multipeaked tuning characteristics, J. Neurophysiol., 2003, 89: 1603–1622.CrossRefGoogle Scholar
  9. 9.
    Chen, Q. C., Jen, P. H. S., Pulse repetition rate increases the mini- mum threshold and latency of auditory neurons, Brain Res., 1994, 654: 115–118.CrossRefGoogle Scholar
  10. 10.
    Chen, Q. C., Jen, P. H. S., Bicuculline affects discharge pattern, rate-intensity function, and frequency tuning characteristics of bat auditory cortical neurons, Hearing Res., 2000, 150: 161–174.CrossRefGoogle Scholar
  11. 11.
    Luan, R. H., Wu, F. J., Jen, P. H. S. et al., Effects of forward mask- ing on the responses of the inferior collicular neurons in the big brown bats,Eptesicus fuscus, Chinese Science Bulletin, 2003, 48(16): 1748–1752.CrossRefGoogle Scholar
  12. 12.
    Casseday, J. H., Covey, E., Frequency tuning properties of neurons in the inferior colliculus of an FM bat, J. Comp. Neurol., 1992, 319: 34–50.CrossRefGoogle Scholar
  13. 13.
    Wenstrup, J. J., Leroy, S. A., Spectral integration in the inferior col- liculus: Role of Glycinergic inhibition in response facilitation, J. Neurosci., 2001, 21(RC124): 1–6.Google Scholar
  14. 14.
    Biebel, U. W., Langner, G., Evidence for interactions across fre- quency channels in the inferior colliculus of awake chinchilla, Hearing Res., 2002, 169: 151–168.CrossRefGoogle Scholar
  15. 15.
    Simmons, J. A., A view of the world through the bat’s ear: The formation of acoustic images in echolocation, Cognition, 1989, 33: 155–159.CrossRefGoogle Scholar
  16. 16.
    Suga, N., Sharpening of frequency tuning by inhibition in the cen- tral auditory system: tribute to Yasuji Katsuki, Neurosci. Res., 1995, 21: 287–289.CrossRefGoogle Scholar
  17. 17.
    Covey, E., Kauer, J. A., Casseday, J. H., Whole-cell patch-clamp recording reveals subthreshold sound-evoked postsynaptic currents in the inferior colliculus of awake bats, J. Neurosci., 1996, 16: 3009–3018.Google Scholar
  18. 18.
    Kuwada, S., Batra, R., Yin, T. C. T. et al., Intracellular recordings in response to monaural and binaural stimulation of neurons in the in- ferior colliculus of the cat, J. Neurosci., 1997, 17: 7565–7581.Google Scholar

Copyright information

© Science in China Press 2004

Authors and Affiliations

  1. 1.School of Life SciencesCentral China Normal UniversityWuhanChina
  2. 2.Division of Biological SciencesUniversity of Missouri-ColumbiaUSA
  3. 3.Laboratory of Visual Information Processing, Institute of BiophysicsChinese Academy of SciencesBeijingChina

Personalised recommendations