Anatomic, intrinsic, and synaptic properties of dorsal and ventral division neurons in rat medial geniculate body

Journal of Neurophysiology

Volumn 81, Issue 5, 1999, Pages 1999-2016

  Bartlett, Edward L ^a   Smith, Philip H ^a  

^a UNIVERSITY OF WISCONSIN MADISON   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

4 AMINOBUTYRIC ACID A RECEPTOR; 4 AMINOBUTYRIC ACID B RECEPTOR; ALPHA AMINO 3 HYDROXY 5 METHYL 4 ISOXAZOLEPROPIONIC ACID; AMPA RECEPTOR; N METHYL DEXTRO ASPARTIC ACID; N METHYL DEXTRO ASPARTIC ACID RECEPTOR; VALERIC ACID DERIVATIVE;

ANIMAL CELL; ARTICLE; AUDITORY STIMULATION; BRAIN NERVE CELL; CELL MEMBRANE; CELL STRUCTURE; DENDRITE; EVOKED RESPONSE; EXCITATORY POSTSYNAPTIC POTENTIAL; INFERIOR COLLICULUS; INHIBITORY POSTSYNAPTIC POTENTIAL; LATENT PERIOD; MEDIAL GENICULATE BODY; NERVE CELL MEMBRANE POTENTIAL; NERVE CELL STIMULATION; NONHUMAN; PRIORITY JOURNAL; RAT; RETICULAR FORMATION; STELLATE CELL; SYNAPSE; THALAMOCORTICAL TRACT;

EID: 0032982274     PISSN: 00223077     EISSN: None     Source Type: Journal    
DOI: 10.1152/jn.1999.81.5.1999     Document Type: Article

References (108)

1. ADAMS, J. C. Heavy metal intensification of DAB-based HRP reaction product. J. Histochem. Cytochem. 29: 775, 1981.
2. AGHAJANIAN, G. K. AND RASMUSSEN. Intracellular studies in the facial nucleus illustrating a simple new method for obtaining viable motor neurons in adult rat brain slices. Synapse 3: 331-338, 1989.
3. AITKIN, L. M. AND PRAIN, S. M. Medial geniculate body: unit responses in the awake cat. J. Neurophysiol. 37: 512-521, 1974.
4. AITKIN, L. M. AND WEBSTER, W. R. Tonotopic organization in the medial geniculate body of the cat. Brain Res. 26: 402-405, 1971.
5. AITKIN, L. M. AND WEBSTER, W. R. Medial geniculate body of the cat: organization and responses to tonal stimuli of neurons in ventral division. J. Neurophysiol. 35: 365-380, 1972.
6. ALLON, N., YESHURUN, Y., AND WOLLBERG, Z. Responses of single cells in the medial geniculate body of awake squirrel monkeys. Exp. Brain Res. 41: 222-232, 1981.
7. ANDERSEN, R. A., ROTH, G. L., AITKIN, L. M., AND MERZENICH, M. M. The efferent projections of the central nucleus and the pericentral nucleus of the inferior colliculus in the cat. J. Comp. Neurol. 194: 649-662, 1980.
8. BAJO, V. M., ROUILLER, E. M., WELKER, E., CLARKE, S., VILLA, A. E., DE RIBAUPIERRE, Y., AND DE RIBAUPIERRE F. Morphology and spatial distribution of corticothalamic terminals originating from the cat auditory cortex. Hear. Res. 83: 161-174, 1995.
9. h) in neurons of the medial nucleus of the trapezoid body: voltage clamp analysis and enhancement by norepinephrine and cAMP suggest a modulatory mechanism in the auditory brainstem. J. Neurophysiol. 70: 1420-1432, 1993.
10. BORDI, F. AND LEDOUX, J. E. Response properties of single units in areas of rat auditory thalamus that project to the amygdala. I. Acoustic discharge patterns and frequency receptive fields. Exp. Brain Res. 98: 261-274, 1994.
11. BOURASSA, J. AND DESCHENES, M. Corticothalamic projections from the primary visual cortex in rats: a single fiber study using biocytin as an anterograde tracer. Neuroscience 66: 253-263, 1995.
12. BOURASSA, J., PINAULT, D., AND DESCHENES, M. Corticothalamic projections from the cortical barrel field to the somatosensory thalamus in rats: a single-fibre study using biocytin as an anterograde tracer. Eur. J. Neurosci. 7: 19-30, 1995.
13. CALFORD, M. B. The parcellation of the medial geniculate body of the cat defined by the auditory response properties of single units. J. Neurosci. 3: 2350-2364, 1983.
14. CALFORD, M. B. AND AITKIN, L. M. Ascending projections to the medial geniculate body of the cat: evidence for multiple, parallel auditory pathways through thalamus. J. Neurosci. 3: 2365-2380, 1983.
15. CALFORD, M. B. AND WEBSTER, W. R. Auditory representation within principal division of cat medial geniculate body: an electrophysiology study. J. Neurophysiol. 45: 1013-1028, 1981.
16. CAMPBELL, G. AND FROST, D. O. Synaptic organization of anomalous retinal projections to the somatosensory and auditory thalamus: target-controlled morphogenesis of axon terminals and synaptic glomeruli. J. Comp. Neurol. 272: 383-408, 1988.
17. CLAREY, J. C., BARONE, P., AND IMIG, T. J. Physiology of thalamus and cortex. In: The Mammalian Auditory Pathway: Neurophysiology, edited by A. N. Popper and R. R. Fay. New York: Springer-Verlag, 1992, p. 232-334.
18. CLERICI, W. J. AND COLEMAN, J. R. Anatomy of the rat medial geniculate body. I. Cytoarchitecture, myeloarchitecture, and neocortical connectivity. J. Comp. Neurol. 297: 14-31, 1990.
19. CLERICI, W. J. AND COLEMAN, J. R. Postnatal cytoarchitecture of the rat medial geniculate body. J. Comp. Neurol. 399: 110-124, 1998.
20. CLERICI, W. J., MCDONALD, A. J., THOMPSON, R., AND COLEMAN, J. R. Anatomy of the rat medial geniculate body. II. Dendritic morphology. J. Comp. Neurol. 297: 32-54, 1990.
21. CONTRERAS, D., DESTEXHE, A., SEJNOWSKI, T. J., AND STERIADE, M. Control of spatiotemporal coherence of a thalamic oscillation by corticothalamic feedback. Science 274: 771-774, 1996.
22. CONTRERAS, D. AND STERIADE, M. Spindle oscillation in cats: the role of corticothalamic feedback in a thalamically generated rhythm [published erratum] J. Physiol. (Lond.) 490: 159-179, 1996.
23. CRABTREE, J. W. Organization in the auditory sector of the cat's thalamic reticular nucleus. J. Comp. Neurol. 390: 167-182, 1998.
24. CRICK, F. AND KOCH, C. Constraints on cortical and thalamic projections: the no-strong-loops hypothesis. Nature 391: 245-250, 1998.
25. CRUNELLI, V., KELLY, J. S., LERESCHE, N., AND PIRCHIO, M. The ventral and dorsal lateral geniculate nucleus of the rat: intracellular recordings in vitro. J. Physiol. (Lond.). 384: 587-601, 1987a.
26. CRUNELLI, V., LERESCHE, N., AND PARNAVELAS, J. G. Membrane properties of morphologically identified X and Y cells in the lateral geniculate nucleus of the cat in vitro. J. Physiol. (Lond.). 390: 243-256, 1987b.
27. DESCHENES, M. AND HU, B. Electrophysiology and pharmacology of the corticothalamic input to lateral thalamic nuclei: an intracelluar study in the cat. Eur. J. Neurosci. 2: 140-152, 1990.
28. DESTEXHE, A., CONTRERAS, D., AND STERIADE, M. Mechanisms underlying the synchronizing action of corticothalamic feedback through inhibition of thalamic relay cells. J. Neurophysiol. 79: 999-1016, 1998.
29. EATON, S. A. AND SALT, T. E. Role of N-methyl-D-aspartate and metabotropic glutamate receptors in corticothalamic excitatory postsynaptic potentials in vivo. Neuroscience 73: 1-5, 1996.
30. ESGUERRA, M., KWON, Y. H., AND SUR, M. Retinogeniculate EPSPs recorded intracellularly in the ferret lateral geniculate nucleus in vitro: role of NMDA receptors. Vis. Neurosci. 8: 545-555, 1992.
31. FRIEDLANDER, M. J., LIN, C. S., STANFORD, L. R., AND SHERMAN, S. M. Morphology of functionally identified neurons in lateral geniculate nucleus of the cat. J. Neurophysiol. 46: 80-129, 1981.
32. GILBERT, C. D. AND KELLY, J. P. The projections of cells in different layers of the cat's visual cortex. J. Comp. Neurol 163: 81-105, 1975.
33. GUIDO, W., LU, S. M., VAUGHAN, J. W., GODWIN, D. W., AND SHERMAN, S. M. Receiver operating characteristic (ROC) analysis of neurons in the cat's lateral geniculate nucleus during tonic and burst response mode. Vis. Neurosci. 12: 723-741, 1995.
34. GUIDO, W. AND WEYAND, T. Burst responses in thalamic relay cells of the awake behaving cat. J. Neurophysiol. 74: 1782-1786, 1995.
35. GUILLERY, R. W. Anatomical evidence concerning the role of the thalamus in corticocortical communication: a brief review. J. Anat. 187: 583-592, 1995.
36. HARTVEIT, E. AND HEGGELUND, P. Neurotransmitter receptors mediating excitatory input to cells in the cat lateral geniculate nucleus. II. Nonlagged cells. J. Neurophysiol. 63: 1361-1372, 1990.
37. HEGGELUND, P. AND HARTVEIT, E. Neurotransmitter receptors mediating excitatory input to cells in the cat lateral geniculate nucleus. I. Lagged cells. J. Neurophysiol. 63: 1347-1360, 1990.
38. HOOGLAND, P. V., WELKER, E., AND VAN DER LOOS, H. Organization of the projections from barrel cortex to thalamus in mice studied with Phaseolus vulgaris-leucoagglutinin and HRP. Exp. Brain Res. 68: 73-87, 1987.
39. HOOGLAND, P. V., WOUTERLOOD, F. G., WELKER, E., AND VAN DER Loos, H. Ultrastructure of giant and small thalamic terminals of cortical origin: a study of the projections from the barrel cortex in mice using Phaseolus vulgaris leuco-agglutinin (PHA-L). Exp. Brain Res. 87: 159-172, 1991.
40. HU, B. Cellular basis of temporal synaptic signalling: an in vitro electrophysiological study in rat auditory thalamus. J. Physiol. (Lond.) 483: 167-182, 1995.
41. HU, B., SENATOROV, V., AND MOONEY, D. Lemniscal and non-lemniscal synaptic transmission in rat auditory thalamus. J. Physiol. (Lond.) 479: 217-231, 1994.
42. HUMPHREY, A. L. AND WELLER, R. E. Structural correlates of functionally distinct X-cells in the lateral geniculate nucleus of the cat. J. Comp. Neurol. 268: 448-468, 1988.
43. IMIG, T. J. AND MOREL, A. Tonotopic organization in ventral nucleus of medial geniculate body in the cat. J. Neurophysiol. 53: 309-340, 1985.
44. IRVINE, D. R. Physiology of the auditory brainstem. In: The Mammalian Auditory Pathway: Neurophysiology, edited by R. R. Fay and A. N. Popper. New York: Springer-Verlag, 1992, p. 152-231.
45. JAHNSEN, H. AND LLINAS, R. Ionic basis for the electro-responsiveness and oscillatory properties of guinea-pig thalamic neurones in vitro. J. Physiol. (Lond.) 349: 227-247, 1984a.
46. JAHNSEN, H. AND LLINAS, R. Electrophysiological properties of guinea-pig thalamic neurones: an in vitro study. J. Physiol. (Lond.) 349: 205-226, 1984b.
47. JONES, E. G. Some aspects of the organization of the thalamic reticular complex. J. Comp. Neurol. 162: 285-308, 1975.
48. JONES, E. G. AND POWELL, T. P. An electron microscopic study of the mode of termination of cortico-thalamic fibres within the sensory relay nuclei of the thalamus. Proc. R. Soc. Lond. B Biol. Sci. 172: 173-185, 1969a.
49. JONES, E. G. AND POWELL, T. P. Electron microscopy of synaptic glomeruli in the thalamic relay nuclei of the cat. Proc. R. Soc. Lond. B Biol. Sci. 172: 153-171, 1969b.
50. JONES, E. G. AND ROCKEL, A. J. The synaptic organization in the medial geniculate body of afferent fibres- ascending from the inferior colliculus. Z. Zellforsch. Mikrosk. Anat. 113: 44-66, 1971.
51. KAO, C. Q. AND COULTER, D. A. Physiology and pharmacology of corticothalamic stimulation-evoked responses in rat somatosensory thalamic neurons in vitro. J. Neurophysiol. 77: 2661-2676, 1997.
52. KUDO, M. AND NIIMI, K. Ascending projections of the inferior colliculus onto the medial geniculate body in the cat studied by anterograde and retrograde tracing techniques. Brain Res. 155: 113-117, 1978.
53. KUDO, M. AND NIIMI, K. Ascending projections of the inferior colliculus in the cat: an autoradiographic study. J. Comp. Neurol. 191: 545-556, 1980.
54. KWON, Y. H., NELSON, S. B., TOTH, L. J., AND SUR, M. Effect of stimulus contrast and size on NMDA receptor activity in cat lateral geniculate nucleus. J. Neurophysiol. 68: 182-196, 1992.
55. LEDOUX, J. E., RUGGIERO, D. A., AND REIS, D. J. Projections to the subcortical forebrain from anatomically defined regions of the medial geniculate body in the rat. J. Comp. Neurol. 242: 182-213, 1985.
56. LUND, J. S., LUND, R. D., HENDRICKSON, A. E., BUNT, A. H., AND FUCHS, A. F. The origin of efferent pathways from the primary visual cortex, area 17, of the macaque monkey as shown by retrograde transport of horseradish peroxidase. J. Comp. Neurol. 164: 287-303, 1975.
57. h. Neuron 20: 553-563, 1998.
58. MAJOROSSY, K. AND Kiss, A. Specific patterns of neuron arrangement and of synaptic articulation in the medial geniculate body. Exp. Brain Res. 26: 1-17, 1976.
59. MAJOROSSY, K. AND RETHELYI, M. Synaptic architecture in the medial geniculate body (ventral division). Exp. Brain Res. 6: 306-323, 1968.
60. MALMIERCA, M. S., REES, A., AND LEBEAU, F.E.N. Ascending projections to the medial geniculate body from physiologically identified loci in the inferior colliculus. In: Acoustical Signal Processing in the Central Auditory System, edited by J. Syka. New York: Plenum Press, 1997, p. 295-302.
61. MCCORMICK, D. A. Functional properties of a slowly inactivating potassium current in guinea pig dorsal lateral geniculate relay neurons. J. Neurophysiol. 66: 1176-1189, 1991.
62. MCCORMICK, D. A. Neurotransmitter actions in the thalamus and cerebral cortex and their role in neuromodulation of thalamocortical activity. Prog. Neurobiol. 39: 337-398, 1992.
63. MCCORMICK, D. A. AND BAL, T. Sensory gating mechanisms of the thalamus. Curr. Opin. Neurobiol. 4: 550-556, 1994.
64. MCCORMICK, D. A. AND PAPE, H. C. Properties of a hyperpolarization-activated cation current and its role in rhythmic oscillation in thalamic relay neurones. J. Physiol. (Lond.) 431: 291-318, 1990a.
65. MCCORMICK, D. A. AND PAPE, H. C. Noradrenergic and serotonergic modulation of a hyperpolarization-activated cation current in thalamic relay neurones. J. Physiol. (Lond.) 431: 319-342, 1990b.
66. MITANI, A., ITOH, K., AND MIZUNO, N. Distribution and size of thalamic neurons projecting to layer I of the auditory cortical fields of the cat compared to those projecting to layer IV. J. Comp. Neurol. 257: 105-121, 1987.
67. MONTERO, V. M. Ultrastructural identification of axon terminals from the thalamic reticular nucleus in the medial geniculate body in the rat: an EM autoradiographic study. Exp. Brain Res. 51: 338-342, 1983.
68. MONYER, H., BURNASHEV, N., LAURIE, D. J., SAKMANN, B., AND SEEBURG, P. H. Developmental and regional expression in the rat brain and functional properties of four NMDA receptors. Neuron 12: 529-540, 1994.
69. MOONEY, D. M., HU, B., AND SENATOROV, V. V. Muscarine induces an anomalous inhibition of synaptic transmission in rat auditory thalamic neurons in vitro. J. Pharmacol. Exp. Ther. 275: 838-844, 1995.
70. MOREST, D. K. The neuronal architecture of the medial geniculate body of the cat. J. Anat. 98: 611-630, 1964.
71. MOREST, D. K. The laminar structure of the medial geniculate body of the cat. J. Anat. 99: 143-160, 1965a.
72. MOREST, D. K. The lateral tegmental system of the midbrain and the medial geniculate body: study with Golgi and Nauta methods in the cat. J. Anat. 99: 611-634, 1965b.
73. NELSON, P. G. AND ERULKAR, S. D. Synaptic mechanisms of excitation and inhibition in the central auditory pathway. J. Neurophysiol. 26: 908-923, 1963.
74. OHARA, P. T. AND HAVTON, L. A. Dendritic architecture of rat somatosensory thalamorcortical projection neurons. J. Comp. Neurol. 341: 159-171, 1994.
75. OJIMA, H. Terminal morphology and distribution of corticothalamic fibers originating from layers 5 and 6 of cat primary auditory cortex. Cereb. Cortex 4: 646-663, 1994.
76. PALLAS, S. L. AND SUR, M. Morphology of retinal axon arbors induced to arborize in a novel target, the medial geniculate nucleus. II. Comparison with axons from the inferior colliculus. J. Comp. Neurol. 349: 363-376, 1994.
77. PAPE, H. C. AND MCCORMICK, D. A. Noradrenaline and serotonin selectively modulate thalamic burst firing by enhancing a hyperpolarization-activated cation current. Nature 340: 715-718, 1989.
78. PAPE, H. C. AND MCCORMICK, D. A. Electrophysiological and pharmacological properties of interneurons in the cat dorsal lateral geniculate nucleus. Neuroscience 68: 1105-1125, 1995.
79. PARE, D., DOSSI, R. C., AND STERIADE, M. Three types of inhibitory postsynaptic potentials generated by interneurons in the anterior thalamic complex of cat. J. Neurophysiol 66: 1190-1204, 1991.
80. PAXINOS, G. AND WATSON, C. The Rat Brain in Stereotaxic Coordinates. San Diego: Academic Press, 1986.
81. PERUZZI, D., BARTLETT, E., SMITH, P. H., AND OLIVER, D. L. A monosynaptic GABAergic input from the inferior colliculus to the medial geniculate body in rat. J. Neurosci. 17: 3766-3777, 1997.
82. ROUILLER, E. M., COLOMB, E., CAPT, M., AND DE RIBAUPIERRE, F. Projections of the reticular complex of the thalamus onto physiologically characterized regions of the medial geniculate body. Neurosci. Let. 53: 227-232, 1985.
83. ROUILLER, E. M. AND DE RIBAUPIERRE, F. Origin of afferents to physiologically defined regions of the medial geniculate body of the cat: ventral and dorsal divisions. Hear. Res. 19: 97-114, 1985.
84. ROUILLER, E. M. AND WELKER, E. Morphology of corticothalamic terminals arising from the auditory cortex of the rat: a Phaseolus vulgaris-leucoagglutinin (PHA-L) tracing study. Hear. Res. 56: 179-190, 1991.
85. RYUGO, D. K. AND WEINBERGER, N. M. Corticofugal modulation of the medial geniculate body. Exp. Neurol. 51: 377-391, 1976.
86. ST. MARIE, R. L., STANFORTH, D. A., AND JUBELIER, E. M. Substrate for rapid feedforward inhibition of the auditory forebrain. Brain Res. 765: 173-176, 1997.
87. SENATOROV, V. V., MOONEY, D., AND HU, B. The electrogenic effects of Na(+)-K(+)-ATPase in rat auditory thalamus. J. Physiol. 502: 375-385, 1997.
88. SENATOROV, V. V. AND HU, B. Differential Na(+)-K(+)-ATPase activity in rat lemniscal and non-lemniscal auditory thalami. J. Physiol. (Lond.) 502: 387-395, 1997.
89. SHOSAKU, A. AND SUMITOMO, I. Auditory neurons in the rat thalamic reticular nucleus. Exp. Brain Res. 49: 432-442, 1983.
90. SMITH, P. H. Anatomy and physiology of multipolar cells in the rat inferior collicular cortex using the in vitro brain slice technique. J. Neurosci. 12: 3700-3715, 1992.
91. STERIADE, M. Synchronized activities of coupled oscillators in the cerebral cortex and thalamus at different levels of vigilance. Cereb. Cortex 7: 583-604, 1997.
92. STERIADE, M., TIMOFEEV, I., DURMULLER, N., AND GRENIER, F. Dynamic properties of corticothalamic neurons and local cortical interneurons generating fast rhythmic (30-40 Hz) spike bursts. J. Neurophysiol. 79:483-490, 1998.
93. SUGA, N., ZHANG, Y., AND YAN, J. Sharpening of frequency tuning by inhibition in the thalamic auditory nucleus of the mustached bat. J. Neurophysiol. 77: 2098-2114, 1997.
94. TENNIGKEIT, F., SCHWARZ, D. W., AND PUIL, E. Mechanisms for signal transformation in lemniscal auditory thalamus. J. Neurophysiol. 76: 3597-3608, 1996.
95. TENNIGKEIT, F., SCHWARZ, D. W., AND PUIL, E. Modulation of bursts and high-threshold calcium spikes in neurons of rat auditory thalamus. Neuroscience 83: 1063-1073, 1998.
96. TURNER, J. P., ANDERSON, C. M., WILLIAMS, S. R., AND CRUNELLI, V. Morphology and membrane properties of neurones in the cat ventrobasal thalamus in vitro. J. Physiol. (Lond.) 505: 707-726, 1997.
97. TURNER, J. P., LERESCHE, N., GUYON, A., SOLTESZ, I., AND CRUNELLI, V. Sensory input and burst firing output of rat and cat thalamocortical cells: the role of NMDA and non-NMDA receptors. J. Physiol. (Lond.) 480: 281-295, 1994.
98. WARREN, R. A., AGMON, A., AND JONES, E. G. Oscillatory synaptic interactions between ventroposterior and reticular neurons in mouse thalamus in vitro. J. Neurophysiol. 72: 1993-2003, 1994.
99. WENZEL, A., FRITSCHY, J. M., MOHLER, H., AND BENKE, D. NMDA receptor heterogeneity during postnatal development of the rat brain: differential expression of the NR2A, NR2B, and NR2C subunit proteins. J. Neurochem. 68: 469-478, 1997.
100. WENZEL, A., SCHEURER, L., KUNZI, R., FRITSCHY, J. M., MOHLER, H., AND BENKE, D. Distribution of NMDA receptor subunit proteins NR2A, 2B, 2C and 2D in rat brain. Neuroreport 7: 45-48, 1995.
101. WINER, J. A. The functional architecture of the medial geniculate body and the primary auditory cortex. In: The Mammalian Auditory Pathway: Neuroanatomy, edited by R. R. Fay, A. N. Popper and D. B. Webster. New York: Springer-Verlag, 1992, p. 222-409.
102. WINER, J. A. AND LARUE, D. T. Anatomy of glutamic acid decarboxylase immunoreactive neurons and axons in the rat medial geniculate body [published erratum appears in J. Comp. Neurol. 280: 499-500, 1989]. J. Comp. Neurol 278: 47-68, 1988.
103. WINER, J. A. AND MOREST, D. K. Axons of the dorsal division of the medial geniculate body of the cat: a study with the rapid Golgi method. J. Comp. Neurol. 224: 344-370, 1984.
104. WINER, J. A. AND MOREST, D. K. The neuronal architecture of the dorsal division of the medial geniculate body of the cat. A study with the rapid Golgi method. J. Comp. Neurol. 221: 1-30, 1983.
105. WINER, J. A., SAINT MARIE, R. L., LARUE, D. T., AND OLIVER, D. L. GABA-ergic feedforward projections from the inferior colliculus to the medial geniculate body. Proc. Natl. Acad. Sci. USA 93: 8005-8010, 1996.
106. YAN, J. AND SUGA, N. Corticofugal modulation of time-domain processing of biosonar information in bats. Science 273: 1100-1103, 1996.
107. ZHANG, Y. AND SUGA, N. Corticofugal amplification of subcortical responses to single tone stimuli in the mustached bat. J. Neurophysiol. 78: 3489-3492, 1997.
108. ZHANG, Y., SUGA, N., AND YAN, J. Corticofugal modulation of frequency processing in bat auditory system. Nature 387: 900-903, 1997.