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The connections and laminar organization ofthe optic tectum in a reptile (lguana iguana).

Publication ,  Journal Article
Foster, RE; Hall, WC
Published in: J Comp Neurol
October 15, 1975

The goals of this study were: (1) to describe the total pattern of projections from the optic tectum of Iguana iguana and Pseudemys scripta; and (2) to describe the contributions of particular lamina of the Iguana's optic tectum to this total pattern. Lesions were made in the optic tectum of the Iguana which damaged either all or only certain tectal laminae and, for comparison with the Iguana, lesions in the turtle's optic tectum were made which involved all laminae. The anterograde degeneration resulting from these lesions was stained with the Fink-Heimer ('67) method. The total pattern of projections from the optic tectum in the Iguana and the turtle is similar to that reported for representatives of other vertebrate classes. That is, the optic tectum gives rise to ipsilateral ascending projections to pretectal nuclei, to nucleus rotundus and to nucleus geniculatus lateralis pars ventralis of the diencephalon and, in addition, to a contralateral ascending pathway which courses via the supraoptic decussation to the contralateral diencephalon. Tectotectal connections and several descending pathways were also recognized in each species. The descending pathways include ipsilateral tectobulbar and tecto-isthmi pathways and a contralateral predorsal bundle. Lesions which damaged only certain tectal laminae in the Iguana revealed a laminar organization of the efferent projections. A lesion restricted to the superficial retinal-recipient layers, stratum griseum et album superficiale, resulted in degeneration in only nucleus isthmi pars magnocellularis and nucleus geniculatus lateralis pars ventralis. A lesion which involved both the retinal-recipient layers and stratum griseum centrale resulted in degeneration in only one additional structure, nucleus rotundus. A small lesion involving the deep periventricular layers as well as the superficial layers produced degeneration in the predorsal bundle and the ipsilateral tectobulbar tract as well as in the structures receiving input from the more superficial layers. These results are compared to the results of similar analyses of the superior colliculus in mammals.

Duke Scholars

Published In

J Comp Neurol

DOI

ISSN

0021-9967

Publication Date

October 15, 1975

Volume

163

Issue

4

Start / End Page

397 / 425

Location

United States

Related Subject Headings

  • Turtles
  • Trigeminal Nerve
  • Superior Colliculi
  • Neurology & Neurosurgery
  • Neural Pathways
  • Mesencephalon
  • Lizards
  • Iguanas
  • Geniculate Bodies
  • Diencephalon
 

Citation

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Foster, R. E., & Hall, W. C. (1975). The connections and laminar organization ofthe optic tectum in a reptile (lguana iguana). J Comp Neurol, 163(4), 397–425. https://doi.org/10.1002/cne.901630403
Foster, R. E., and W. C. Hall. “The connections and laminar organization ofthe optic tectum in a reptile (lguana iguana).J Comp Neurol 163, no. 4 (October 15, 1975): 397–425. https://doi.org/10.1002/cne.901630403.
Foster RE, Hall WC. The connections and laminar organization ofthe optic tectum in a reptile (lguana iguana). J Comp Neurol. 1975 Oct 15;163(4):397–425.
Foster, R. E., and W. C. Hall. “The connections and laminar organization ofthe optic tectum in a reptile (lguana iguana).J Comp Neurol, vol. 163, no. 4, Oct. 1975, pp. 397–425. Pubmed, doi:10.1002/cne.901630403.
Foster RE, Hall WC. The connections and laminar organization ofthe optic tectum in a reptile (lguana iguana). J Comp Neurol. 1975 Oct 15;163(4):397–425.
Journal cover image

Published In

J Comp Neurol

DOI

ISSN

0021-9967

Publication Date

October 15, 1975

Volume

163

Issue

4

Start / End Page

397 / 425

Location

United States

Related Subject Headings

  • Turtles
  • Trigeminal Nerve
  • Superior Colliculi
  • Neurology & Neurosurgery
  • Neural Pathways
  • Mesencephalon
  • Lizards
  • Iguanas
  • Geniculate Bodies
  • Diencephalon