Single units in the medial genioulate body and inferior colliculus of the cat were activated by acoustic stimulation and their activity was tested by orthodromic conditioning stimulation of the auditory cortex with the following findings;
Two groups of the cells in the medial geniculate body and the inferior colliculus, activated by both cortical electric stimulation and tonal stimulation, have been classified as „modification” units and “no modification” units.
Corticofugal stimulation inhibited or facilitated “modification” units. “No modification” units were subdivided into a) units with no electrical response, b) units with independent responses to both auditory and electrical stimulation, c) units with electrical response only. These were believed to be, respectively, principal neurons, inhibitory interneurons and excitatory (efferent) interneurons.
In general, fibers from AI elicit inhibitory while those from AII elicit facilitatory effects in the medial geniculate body.
Cortical stimulation produced a threshold change on the response area of “modification” units.
It is concluded that a number of, not very many, centrifugal fibers innervate the ipsilateral geniculate neurons.
In agreement with anatomical findings, physiological evidence suggests that corticofugal fibers from both auditory cortices innervate inferior colliculus neurons. Their modification patterns were same as those of geniculate units except the latency of responses was much longer.
A centrifugal control mechanism may play an important role in the frequency selective gating mechanism of the central auditory system.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Andersen, P., J.C. Eccles and T.A. Sears: The ventro-basal complex of the thalamus: Types of cells, their responses and their functional organization. J. Physiol. (Lond.) 174, 370–399 (1964).
Bishop, P.O., W. Burke and R. Davis: Single unit recording from antidromically activated optic radiation neurons. J. Physiol. (Lond.) 162, 432–450 (1962).
Calma, I.: Thalamo-cortical relations in the sensory nuclei of the cat. Nature (Lond.) 205, 394–396 (1965).
Desmbdt, J.E., and K. Mechelse: Corticofugal projections from temporal lobe in cat and their possible role in acoustic discrimination. J. Physiol. (Lond.) 147, 17–18 (1959).
—, and P. Monaco: Mode of action of the efferent olivo-cochlear bundle of the inner ear. Nature (Lond.) 192, 1263–1265 (1961).
Fex, J.: Auditory activity in centrifugal and centripetal cochlear fibers in cat: A study of a feedback system. Acta physiol. Scand. 55, Suppl. (1962).
Galambos, R.: Suppression of auditory nerve activity by stimulation of efferent fibers to cochlea. J. Neurophysiol. 19, 424–437 (1956).
Granit, R.: Receptors and Sensory Reception. New Haven: Yale Univ. Press 1955.
Hagbarth, K.E., and D.I.B. Kerr: Central influences on spinal afferent conduction. J. Neurophysiol. 17, 295–307 (1954).
—, and J. Fex: Centrifugal influences and single unit activity in spinal sensory paths. J. Neurophysiol. 22, 321–338 (1959).
Hernández-Peón, R., H. Scherrer, and M. Jouvet: Modification of electrical activity in cochlear nucleus during “attention” in unanesthetized cats. Science 123, 331–332 (1956).
Hernández-Peón, R. Reticular mechanisms of sensory control. ‘Sensory Communication’ (W.A. Rosenblith edit.) John Wiley 1961.
Jabbur, S.J., and A.L. Towe: Cortical excitation of neurons in dorsal column nuclei of cat including on analysis of pathways. J. Neurophysiol. 24, 499–509 (1961).
Jasper, H.H., and C. Ajmone Marsan: A stereotaxic atlas of the diencephalon of the cat. Nat. Res. Council Canada 1954.
Katsuki, Y., T. Watanabe and N. Maruyama: Activity of auditory neurons in upper levels of brain of cat. J. Neurophysiol. 22, 343–359 (1959).
Kuffler, S.W.: Synaptic inhibitory mechanisms. Properties of dendrites and problems of excitation in isolated sensory nerve cells. Exp. Cell Res. Suppl. 5, 493–519 (1958).
Lilly, J.C.: Equipotential maps of the posterior ectosylvian area and acoustic I and II of the cat during responses and spontaneous activity. Fed. Proc. 10, 84 (1951).
Massopust, Leo. C., and J.M. Ordy: Auditory organization of the inferior colliculi in the cat. Exp. Neurol. 6, 465–477 (1942).
Morest, D. Kent: The probable significance of synaptic and dendritic patterns of the thalamic and midbrain auditory system. Anat. Rec. 148, 390–391 (1964).
— The neuronal architecture of the medial geniculate body of the cat. J. Anat. (Lond.) 98, 611–630 (1965a).
— The laminar structure of the medial geniculate body of the cat. J. Anat. (Lond.) 99, 143–160 (1965b).
Oonishi, S., and Y. Katsuki: Functional organization and integrative mechanism on the auditory cortex of the cat. Jap. J. Physiol. 15, 342–365 (1965).
Otani, K., and M. Hiura: Projection fibers from the auditory cortex of the cat. Progr. Neurol. Psychiat. 7, 485–494 (1962) (in Japanese).
Rasmussen, G.L.: The olivary peduncle and other fibers projections of the superior olivary complex. J. comp. Neurol. 84, 141–220 (1946).
— Further observations of the efferent cochlear bundle. J. comp. Neurol. 99, 61–74 (1953a).
— Recurrent or “feedback” connections of the auditory system of the cat. Anat. Rec. 115, 361 (1953b).
— Descending or “feedback” connections of auditory system of the cat. Amer. J. Physiol. 183, 653 (1955).
Rose, J.E., and C.N. Woolsey: The relations of the thalamic connections, cellular structure and evocable electrical activity in the auditory region of the cat. J. comp. Neurol. 91, 441–446 (1949).
Sefton, Ann J., and W. Burke: Reverberating inhibitory circuits in the lateral geniculate nucleus of the rat. Nature (Lond.) 205, 1325–1326 (1965).
Suzuki, H., and N. Taira: Effect of reticular stimulation upon synaptic transmission in cat's lateral geniculate body. Jap. J. Physiol. 11, 641–655 (1961).
Wall, P.D.: Repetitive discharge of neurons. J. Neurophysiol. 22, 305–320 (1959).
Watanabe, T.: A single neuron activity in the secondary cortical auditory area in the cat. Jap. J. Physiol. 9, 245–256 (1959).
Widen, L., and C. Ajmone Marsan: Effects of corticipetal and corticifugal impulses upon single elements of the dorsolateral geniculate nucleus. Exp. Neurol. 2, 468–502 (1960).
Winter, D.L.: N. Gracilis of cat. Functional organization and corticofugal effects. J. Neurophysiol. 28, 48–70 (1965).
About this article
Cite this article
Watanabe, T., Yanagisawa, K., Kanzaki, J. et al. Cortical efferent flow influencing unit responses of medial geniculate body to sound stimulation. Exp Brain Res 2, 302–317 (1966). https://doi.org/10.1007/BF00234776
- Auditory cortical efferent
- Medial geniculate body