The locations and distribution of corticothalamic projections from various somatotopic representation areas of the primary motor (MI) and sensory (SI) areas of the cortex were studied in cats. Efferent fibers from MI neurons (fields 4y, 6ab) were found mainly to terminate in the ventral posterolateral and posteromedial (VPL, VPM), ventrolateral (VL), and reticular (R) nuclei, located in the rostral part of the thalamus, in contrast to the situation with the SI (fields 1, 2, 3a, 3b), which projected mainly to the caudal part of the thalamus, to the VPL, VPM, and R nuclei. A lateromedial organization was demonstrated for corticothalamic connections, with the cortical representation areas of the hindlimb being located mainly in the lateral part of the VPL nucleus, those of the forelimbs in the medial part, and those of the face and head being located not only in the VPL nucleus, but also in the VM and VPM nuclei. Quantitative comparison of the distributions of corticothalamic efferent fibers from different somatotopic representation areas in MI showed that the most extensive and massive connections with the thalamic nuclei (the VPL, VL, and R) bore the motor representation of the forelimbs, followed by the hindlimbs, trunk, and, finally, the face and head, which had the minimal level of representation. In contrast to the motor representation of the forelimbs and the face and head, which had a uniform distribution of fibers in the VPL, VL and R nuclei, the number of efferent fibers for the motor representation of the hindlimbs running to the VL nucleus was 2.5 times smaller than the numbers in the VPL and R nuclei, while the representation of the trunk projected mainly to the VL. The dominance of the corticothalamic connection is evidence for a greater level of involvement of the thalamic nuclei in supporting the functional specialization of particular somatotopic representations in the MI.
Similar content being viewed by others
References
N. M. Ipekchyan and S. A. Badalyan, “The primary motor and primary sensory cortex – two local cortical centers of the sensorimotor representation of the body,” Morfologiya, 143, No. 2, 7–12 (2013).
T. A. Leontovich, The Neuronal Organization of the Subcortical Formations of the Forebrain, Meditsina, Moscow (1978).
A. A. Skoromets, A. P. Skoromets, and T. A. Skoromets, “Topical diagnosis of focal lesions of the nervous system,” in: Nervous Diseases, MEDpress Inform, Moscow (2008), pp. 197–220.
C. E. Castman-Berrevoets and H. G. J. M. Kuypers, “Differential laminar distribution of corticothalamic neurons projecting to the VL and center median, An HRP study in the cynomolgus monkey,” Brain Res., 154, No. 2, 359–365 (1978).
C. Duval, M. Panisset, A. P. Strafelia, and A. F. Sadiket, “The impact of ventrolateral thalamotomy on tremor and voluntary motor behavior in patients with Parkinson’s disease,” Exp. Brain Res., 170, No. 2, 160–171 (2006).
P. Golshani, X.-B. Liu, and E. G. Jones, “Differences in quantal amplitude reflect GLUR4-subunit number at corticothalamic synapses on two populations of thalamic neurons,” Proc. Natl. Acad. Sci. USA, 98, 4172–4177 (2001).
A. Groh, B. Hajnalka, A. M. Rebecca, et al., “Convergence of cortical and sensory driver inputs on single thalamocortical cells,” Cereb. Cortex, 24, No. 12, 3167–3179 (2014).
R. W. Guillery and S. M. Sherman, “Branched the thalamic afferents: What are the messages that they relay to the cortex?” Brain Res. Rev., 66, 205–219 (2011).
R. Hassler and K. Muhs-Clement, “Architectonischer Aufbau des sensomotorischen und parietalen Cortex der Katze,” J. Hirnforsch., 6, No. 4, 377–420 (1964).
H. H. Jasper and G. A. Ajmone-Marsan, A Stereotaxic Atlas of the Diencephalon of the Cat, National Research Council, Ottawa (1954).
E. G. Jones, “Thalamic circuitry and thalamocortical synchrony,” Philos. Trans. R. Soc. Lond. B, 357, 1659–1973 (2002).
E. G. Jones and H. Burton, “Cytoarchitecture and somatic sensory connectivity of thalamic nuclei other than the ventrobasal complex in the cat,” J. Comp. Neurol., 154, No. 4, 395–432 (1974).
E. G. Jones and D. P. Friedman, “Projection pattern of functional components of thalamic ventrobasal complex on monkey somatosensory cortex,” J. Neurophysiol., 48, No. 2, 521–544 (1982).
E. G. Jones, D. P. Friedman, and S. H. C. Hendry, “Thalamic basis of place and modality-specific columns in monkey somatosensory cortex: a correlative anatomical and physiological study,” J. Neuro physiol., 48, No. 2, 545–568 (1982).
E. G. Jones and S. P. Wise, “Size, laminar and columnar distribution of efferent cells in the sensory-motor cortex of monkeys,” J. Comp. Neurol., 175, No. 4, 391–438 (1977).
E. G. Jones, S. P. Wise, and J. D. Goulter, “Differential thalamic relationships of sensory-motor and parietal cortical fields in monkeys,” J. Comp. Neurol., 183, No. 4, 833–882 (1979).
J. H. Kaas, R. J. Nelson, M. Sur, et al., “The somatotopic organization of the ventroposterior thalamus of the squirrel monkey, Saimiri sciureus,” J. Comp. Neurol., 226, No. 1, 111–140 (1984).
M. M. Mesulam, “Tetramethylbenzidine for horseradish peroxidase neurochemistry: a non-carcinogenic blue reaction product with superior sensitivity for visualizing neural afferents and efferents,” J. Histochem. Cytochem., 26, No. 2, 106–117 (1978).
J. Na, S. Kakei, and Y. Shinoda, “Cerebellar input to corticothalamic neurons in layers V and VI in the motor cortex,” Neurosci. Res., 28, No. 1, 77–91 (1997).
W. J. H. Nauta and P. A. Gygax, ��A silver impregnation of degenerating axons in the central nervous system: a modified technic,” Stain Technol., 29, No. 1, 91–93 (1954).
A. Nieoullon and L. Respal-Padel, “Somatotopic localization in cat motor cortex,” Brain Res., 105, No. 3, 405–422 (1976).
I. Petrof, A. N. Viaene, and S. M. Sherman, “Two populations of corticothalamic and interareal corticocortical cells in the subgranular layers of the mouse primary sensory cortices,” J. Comp. Neurol., 520, No. 8, 1678–1686 (2012).
E. Rinvik, “A re-evaluation of the cytoarchitecture of the ventral nuclear complex of the cat’s thalamus on the basis of corticothalamic connections,” Brain Res., 8, No. 2, 237–254 (1968).
E. Rinvik, “The corticothalamic projection from the pericruciate and coronal gyri in the cat. An experimental study with silver impregnation methods,” Brain Res., 10, No. 2, 79–119 (1968).
I. Rosen and C. Asanuma, “Peripheral afferent input to the forelimb area of the monkey motor cortex: input-output relationship,” Exp. Brain Res., 14, 257–273 (1972).
D. J. Tracey, C. Asanuma, E. G. Jones, and R. Porter, “Thalamic relay to motor cortex: Afferent pathways from brain stem, cerebellum and spinal cord in monkeys,” J. Neurophysiol., 44, No. 3, 532–554 (1980).
Author information
Authors and Affiliations
Corresponding author
Additional information
Translated from Morfologiya, Vol. 149, No. 1, pp. 15–21, January–February, 2016.
Rights and permissions
About this article
Cite this article
Ipekchyan, N.M., Badalyan, S.A. Distribution of Corticothalamic Projections from Various Somatotopic Representation Areas of the Primary Motor and Sensory Cortex. Neurosci Behav Physi 47, 1–6 (2017). https://doi.org/10.1007/s11055-016-0358-y
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11055-016-0358-y