Conditioning pp 697-710 | Cite as

Sensory Plasticity and Learning: The Magnocellular Medial Geniculate Nucleus of the Auditory System

  • Norman M. Weinberger
Part of the Advances in Behavioral Biology book series (ABBI, volume 26)


The magnocellular medial genículate nucleus (MGm) is a nonlemniscal component of the thalamo-cortical auditory system. It develops discharge plasticity rapidly during behavioral conditioning, in contrast to the ventral medial geniculate, the lemniscal and non-plastic component. Continual recordings from single cells during the acquisition of the pupillary conditioned response reveals an exceptionally high proportion of plastic neurons, the most plastic of which have a pronounced onset discharge to initial presentation of acoustic stimuli. Facilitation of monosynaptic field potentials in MGm lasts for several hours following brief high-frequency stimulation of its major afferent, with respect both to increased amplitude and decreased latency. Responses of single units are also facilitated for hours, as indexed by increased probability of discharges and decreased latency and latency variability. Together, these findings suggest a functional relationship between conditioning and long-lasting facilitation. Moreover, they underscore the capacity of the auditory system to express physiological plasticity under a variety of circumstances.


Conditioned Stimulus Auditory System Inferior Colliculus Tree Shrew High Frequency Stimulation 
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  1. Ashe, J. H., Cassady, J. M., and Weinberger, N. M., 1976, The relationship of the cochlear microphonic potential to the acquisition of a classically conditioned pupillary dilation response, Behay. Biol., 16: 45.CrossRefGoogle Scholar
  2. Birt, D., Nienhuis, R., and Olds, M., 1978, Separation of associative from non-associative short latency changes in medial geniculate and inferior colliculus during differential conditioning and reversal in rats, Soc. Neurosci. Abst., 4: 255.Google Scholar
  3. Bliss, T. V. P. and L$mo, T., 1973, Long lasting potentiation of synaptic transmission in the dentate area of the anaesthetized rabbit following stimulation of the perforant path. J. Physiol., 232: 331.PubMedGoogle Scholar
  4. Buchwald, J. S., Halas, E. S., and Schramm, S., 1966, Changes in cortical and subcortical unit activity during behavioral conditioning, Physiol. Behay., 1: 11.CrossRefGoogle Scholar
  5. Disterhoft, J. F. and Stuart, D. K., 1976, Trial sequence of changed unit activity in auditory system of alert rat during conditioned response acquisition and extinction, J. Neurophysíol., 39: 266.PubMedGoogle Scholar
  6. Fitzpatrick, K. A. and Imig, T. J., 1978, Projections of auditory cortex upon the thalamus and midbrain in the owl monkey. J. Comp. Neurol., 177: 537.CrossRefGoogle Scholar
  7. Gabriel, M., Miller, J. D., and Saltwick, S. E., 1976, Multiple unit activity of the rabbit medial geniculate nucleus in conditioning, extinction, and reversal, Physiol. Psychol., 4: 124.Google Scholar
  8. Graybiel, A. M., 1972, Some fiber pathways related to the posterior thalamic region in the cat, Brain Behay., Evol., 6: 363.CrossRefGoogle Scholar
  9. Jordan, H., 1973, The structure of the medial genículate nucleus (MON): A cyto-and myeloarchitectonic study in the squirrel monkey, J. Comp. Neurol., 148: 469.PubMedCrossRefGoogle Scholar
  10. Kandel, E. R., 1978, A cell-biological approach to learning, Soc. Neurosci., Bethesda, Md.Google Scholar
  11. Kuhn, T. S., 1962, The Structure of Scientific Revolutions, University of Chicago Press, Chicago, Illinois.Google Scholar
  12. Miller, J. D., 1979, Multiple unit activity in the rabbit thalamus and inferior collículus during differential avoidance conditioning and reversal, Unpublished doctoral thesis, University of Texas.Google Scholar
  13. Moore, R. Y. and Goldberg, J. M., 1963, Ascending projections of the inferior colliculus in the cat, J. Comp. Neurol., 121: 109.CrossRefGoogle Scholar
  14. Morest, D. K., 1964, The neuronal architecture of the medial geniculate body of the cat, J. Anat. (Lond.), 98: 611.Google Scholar
  15. Olds, J., Disterhoft, J. F., Segal, M., Kornblith, C. L., and Hirsh, R., 1972, Learning centers of rat brain mapped by measuring latencies of conditioned unit responses, J. Neurophysiol., 35: 202.PubMedGoogle Scholar
  16. Oleson, T. D., Ashe, J. H., and Weinberger, N. M., 1975, Modification of auditory and somatosensory system activity during pupillary conditioning in the paralyzed cat, J. Neurophysiol., 38: 1114.PubMedGoogle Scholar
  17. Oleson, T. D. Vododnick. D. S., and Weinberger, N. M., 1973, Pupillary inhibition of delay during Pavlovian conditioning in paralyzed cat, Behay. Biol., 8: 337.CrossRefGoogle Scholar
  18. Oleson, T. D., Westenberg, I. S., and Weinberger, N. M., 1972, Characteristics of the pupillary dilation response during Pavlovian conditioning in paralyzed cats, Behay. Biol., 7: 829.CrossRefGoogle Scholar
  19. Oliver, D. L. and Hall, W. C., 1975, Subdivisions of the medial geniculate body in the tree shrew (Tapaia glis), Brain Res., 86: 217.PubMedCrossRefGoogle Scholar
  20. Ramon y Cajal, S., 1966, Studies on the Diencephalon, Trans. by E. Ramon-Moliner, Charles C. Thomas, Springfield, Ill.Google Scholar
  21. Ryugo, D. K. and Killackey, H. P., 1974, Differential telencephalic projections of the medial and ventral divisions of the medial geniculate body of the rat, Brain Res., 82: 173.PubMedCrossRefGoogle Scholar
  22. Ryugo, D. K. and Weinberger, N. M., 1976, Differential plasticity of morphologically distinct neuron populations in the medial geniculate body of the cat during classical conditioning, Soc. Neurosci. Abst., 2: 435.Google Scholar
  23. Ryugo, D. K. and Weinberger, N. M., 1978, Differential plasticity of morphologically distinct neuron populations in the medial geniculate body of the cat during classical conditioning, Behay. Biol., 22: 275.CrossRefGoogle Scholar
  24. Weinberger, N. M., 1980, Neurophysiological studies of learning in association with the pupillary dilation conditioned reflex, in: Neural Mechanisms of Goal-Directed Behavior and Learning Google Scholar
  25. R. F. Thompson, L. H. Hicks, and V. B. Shvyrkov, eds., Academic Press, New York, pp. 241–261.Google Scholar
  26. Weinberger, N. M., 1981, Effects of conditioned arousal on the auditory system, in: The Neural Basis of Behavior, A. L. Beckman, ed., Spectrum Publishing Co., Jamaica, N.Y.Google Scholar
  27. Weinberger, N. M., Oleson, T. D., and Haste, D., 1973, Inhibitory control of conditional pupillary dilation response in the paralyzed cat, Behay. Biol., 9: 307.CrossRefGoogle Scholar
  28. Woody, C. D., 1974, Aspects of the electrophysiology of cortical processes related to the development and performance of learned motor responses, The Physiologist, 17: 49.PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1982

Authors and Affiliations

  • Norman M. Weinberger
    • 1
  1. 1.Department of PsychobiologyUniversity of CaliforniaIrvineUSA

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