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Differences in FM response correlate with morphology of neurons in the rat inferior colliculus

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Summary

The response characteristics to linear frequency sweeps were studied in two groups of FM (frequency modulation) sensitive neurons in the rat inferior colliculus. ‘FM specialized’ cells responded to frequency sweeps but not to pure tones. ‘Mixed’ cells responded to both frequency sweeps and pure tones. FM specialized cells preferred faster and broader sweeps of higher intensity than did mixed cells and were more directionally selective. In addition, FM specialized cells were more sharply tuned to FM velocity and FM range and had longer response latencies. Physiologically identified FM cells stained intracellularly with horseradish peroxidase revealed differences in morphology correlating with the differences in their responses to tones. FM specialized cells had larger dendritic fields, more dendritic branching and more dendritic spines than did mixed cells. The findings are taken as evidence that the two groups of inferior colliculus neurons are both functionally and morphologically distinct.

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References

  1. Adams JC (1977) Technical considerations on the use of horseradish peroxidase as a neuronal marker. Neuroscience 2:141–145

  2. Aitkin LM (1986) The auditory midbrain. Humana Press, Clifton

  3. Bishop GA, King JS (1982) Intracellular horseradish peroxidase injections for tracing neural connections. In: Mesulam MM (eds) Methods in neurosciences: tracing neural connections with horseradish peroxidase. Wiley, New York, pp 185–247 (IBRO handbook series)

  4. Britt R, Starr A (1976) Synaptic events and discharge patterns of cochlear nucleus cells: II frequency-modulated tones. J Neurophysiol 39:179–194

  5. Clopton BM, Winfield JA (1973) Tonotopic organization in the inferior colliculus of the rat. Brain Res 56:355–358

  6. Clopton BM, Winfield JA (1974) Unit responses in the inferior colliculus of rat to temporal auditory patterns of tone sweeps and noise bursts. Exp Neurol 42:532–540

  7. Coleman JR, Campbell M, Clerici WJ (1982) Observations on tonotopic organization within the rat inferior colliculus using 2-deoxy-D-[1–3H] glucose. Otolaryngol Head Neck Surg 90:795–800

  8. Erulkar SD, Nelson PG, Bryan JS (1968) Experimental and theoretical approaches to neural processing in the central auditory pathway. In: Neff WD (ed) Contributions to sensory physiology, vol 3. Academic Press, New York, pp 149–189

  9. Evans EF, Whitfield IC (1964) Responses of cortical neurons to acoustic stimuli varying periodically in frequency. J Physiol (Lond) 172:52

  10. Faye-Lund H, Osen KK (1985) Anatomy of the inferior colliculus in rat. Anat Embryol 171:1–20

  11. Fernand RD (1971) A neuron model with spatially distributed synaptic input. Biophys J 11:323–340

  12. Huang C-M, Fex J (1986) Tonotopic organization in the inferior colliculus of the rat demonstrated with the 2-deoxyglucose method. Exp Brain Res 61:506–512

  13. Kay RH (1982) Hearing of modulation in sounds. Physiol Rev 62:894–969

  14. Kiang NYS (1975) Stimulus representation in the discharge patterns of auditory neurons. In: Tower DB et al (eds) The nervous system Vol 3. Human communication and its disorders. Raven Press, New York, pp 81–96

  15. Kiang NYS, Liberman CM, Levine RA (1976) Auditory-nerve activity in cats exposed to ototoxic drugs and high-intensity sounds. Ann Otol Rhinol Laryngol 75:1–17

  16. Liberman CM (1984) Single-neuron labeling and chronic cochlear pathology. I. Threshold shift and characteristic-frequency shift. Hearing Res 16:33–41

  17. Mendelson JR, Cynader MS, Douglas RM (1985) Responses of single neurons in cat auditory cortex to time-varying stimuli: frequency-modulated tones of narrow excursion. Exp Brain Res 58:443–454

  18. Morest DK, Oliver DL (1984) The neuronal architecture of the inferior colliculus in the cat: defining the functional anatomy of the auditory midbrain. J Comp Neurol 222:209–236

  19. Nelson PG, Erulkar SD, Bryan JS (1966) Responses of units of the inferior colliculus to time-varying acoustic stimuli. J Neurophysiol 29:834–860

  20. Oliver DL, Morest DK (1984) The central nucleus of the inferior colliculus in the cat. J Comp Neurol 222:237–264

  21. Oliver DL, Kuwada S, Yin TCT, Baberly LB, Henkel CK (1991) Dendritic and axonal morphology of HRP-injected neurons in the inferior colliculus of the cat. J Comp Neurol 303:75–100

  22. Phillips DP, Mendelson JR, Cynader MS (1985) Sensitivity of cat primary auditory cortex (AI) neurons to the direction and rate of frequency modulation. Brain Res 327:331–335

  23. Poon PWF, Chen XY, Hwang JC (1990a) Cytomorphological difference of 2 types of FM cells in the rat. Soc Neurosci Abstr 16:723

  24. Poon PWF, Chen X, Hwang JC (1990b) Altered sensitivities of auditory neurons in the rat midbrain following early postnatal exposure to patterned sounds. Brain Res 524:327–330

  25. Poon PWF, Chen X, Hwang JC (1991) Basic determinants for FM responses in the inferior colliculus of rats. Exp Brain Res 83:598–606

  26. Rees A, Moller AR (1983) Responses of neurons in the inferior colliculus of the rat to AM and FM tones. Hearing Res 10:301–330

  27. Rockel AJ, Jones EG (1973) The neuronal organization of the inferior colliculus of the adult cat. I. The central nucleus. J Comp Neurol 147:11–60

  28. Ryan AF, Furlow Z, Woolf NK, Keithley EM (1988) The spatial representation of frequency in the rat dorsal cochlear nucleus and inferior colliculus. Hearing Res 36:181–190

  29. Ryugo DK (1976) An attempt towards an integration of structure and function in the auditory system. Doctoral thesis. University of California, Irvine

  30. Sinex DG, Geisler CD (1981) Auditory-nerve fiber responses to frequency-modulated tones. Hearing Res 4:127–148

  31. Stiebler I, Ehret G (1985) Inferior colliculus of the house mouse. I. A Quantitative study of tonotopic organization, frequency representation, and tone-threshold distribution. Comp Neurol 238:65–76

  32. Suga N (1965a) Analysis of frequency-modulated sounds by auditory neurons of echo-locating bats. J Physiol (Lond) 179:26–53

  33. Suga N (1965b) Responses of cortical auditory neurons to frequency modulated sounds in echo-locating bats. Nature 206:890–891

  34. Suga N (1965c) Functional properties of auditory neurons in the cortex of echo-locating bats. J Physiol (Lond) 181:671–700

  35. Suga (1968) Analysis of frequency-modulated and complex sounds by single auditory neurons of bats. J Physiol (Lond) 198:51–80

  36. Suga N (1969) Classification of inferior collicular neurons of bats in terms of responses to pure tones, FM sounds and noise bursts. J Physiol (Lond) 200:555–574

  37. Watanabe T, Ohgushi K (1968) FM sensitive auditory neurons. Proc Jpn Acad 44:968–973

  38. Whitfield IC, Evans EF (1965) Responses of auditory cortical neurons to stimuli of changing frequency. J Neurophysiol 28:655–672

  39. Xu JF, Poon WF, Chen XY, Chung SN (1990) Computer-assisted three dimensional reconstruction of nuclear subdivisions in the inferior colliculus (in Chinese). Comput Engin Applicat 6:7–10

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Poon, P.W.F., Chen, X. & Cheung, Y.M. Differences in FM response correlate with morphology of neurons in the rat inferior colliculus. Exp Brain Res 91, 94–104 (1992). https://doi.org/10.1007/BF00230017

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Key words

  • Frequency modulation
  • Intracellular recordings
  • Horseradish peroxidase
  • Inferior colliculus
  • Rat