An autoradiographic study of cortical projections from motor thalamic nuclei in the macaque monkey

AbstractStructural connections between cortical areas form an intricate network with a high degree of specificity. Many aspects of this complex network organization in the adult mammalian cortex are captured by an architectonic type principle, which relates structural connections to the architectonic differentiation of brain regions. In particular, the laminar patterns of projection origins are a prominent feature of structural connections that varies in a graded manner with the relative architectonic differentiation of connected areas in the adult brain. Here we show that the architectonic type principle is already apparent for the laminar origins of cortico-cortical projections in the immature cortex of the macaque monkey. We find that prenatal and neonatal laminar patterns correlate with cortical architectonic differentiation, and that the relation of laminar patterns to architectonic differences between connected areas is not substantially altered by the complete loss of visual input. Moreover, we find that the degree of change in laminar patterns that projections undergo during development varies in proportion to the relative architectonic differentiation of the connected areas. Hence, it appears that initial biases in laminar projection patterns become progressively strengthened by later developmental processes. These findings suggest that early neurogenetic processes during the formation of the brain are sufficient to establish the characteristic laminar projection patterns. This conclusion is in line with previously suggested mechanistic explanations underlying the emergence of the architectonic type principle and provides further constraints for exploring the fundamental factors that shape structural connectivity in the mammalian brain.

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Topographical projections of the prestriate cortex to the pulvinar nuclei in the macaque monkey: An autoradiographic study

Experimental Brain Research ◽

10.1007/bf00237265 ◽

1977 ◽

Vol 30-30 (2-3) ◽

Cited By ~ 10

Author(s):

L.A. Benevento ◽

B. Davis

Keyword(s):

Macaque Monkey ◽

Autoradiographic Study ◽

Prestriate Cortex

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The cortical projections of the mediodorsal nucleus and adjacent thalamic nuclei in the rat

The Journal of Comparative Neurology ◽

10.1002/cne.901710204 ◽

1977 ◽

Vol 171 (2) ◽

pp. 157-191 ◽

Cited By ~ 949

Author(s):

J. E. Krettek ◽

J. L. Price

Keyword(s):

Thalamic Nuclei ◽

Mediodorsal Nucleus ◽

Cortical Projections

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An autoradiographic study of the retino-cortical projections in the tree shrew (Tupaia glis)

Brain Research ◽

10.1016/0006-8993(75)90568-5 ◽

1975 ◽

Vol 96 (1) ◽

pp. 41-50 ◽

Cited By ~ 78

Author(s):

David H. Hubel

Keyword(s):

Tree Shrew ◽

Autoradiographic Study ◽

Cortical Projections ◽

Tupaia Glis

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Primary Graviceptive System and Astasia: Case Report and Literature Review

10.21203/rs.3.rs-833382/v1 ◽

2021 ◽

Author(s):

Ko-Ting Chen ◽

Sheng-Yao Huang ◽

Yi-Jye Chen

Keyword(s):

English Literature ◽

Vestibular Nuclei ◽

Subcortical White Matter ◽

Upright Posture ◽

Neural Pathways ◽

Thalamic Nuclei ◽

Cortical Areas ◽

Cortical Projections ◽

Contralateral Projection ◽

Motor Strength

Abstract Purpose of ReviewAstasia refers to the inability to maintain upright posture during standing, despite having full motor strength. However, the pathophysiology and neural pathways of astasia remains unclear.Recent FindingsWe analyzed 26, including ours, non-psychogenic astasia patients in English literature. Seventy-three percent of them were man, 73% were associated with other neurologic symptoms and 62% of reported lesions were at right side. Contralateral lateropulsion was very common followed by retropulsion while describing astasia. Infarction (54%) was the most commonly reported cause. Thalamus (65%) was the most commonly reported location. Infarction being the mostly likely to recover (mean:10.6 days), while lesions at brainstem had longer time to recover (mean: 61.6 days).SummaryThe underlying interrupted pathway may be the primary graviceptive system, which composed of at least five unilateral and contralateral projection fibers from vestibular nuclei to thalamic nuclei, and thalamo-cortical projections including subcortical white matter tracts and cortical areas.

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