Specificity in the axonal connections of layer VI neurons in tree shrew striate cortex: Evidence for distinct granular and supragranular systems

William Martin Usrey, David Fitzpatrick

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

Pyramidal neurons in layer VI of striate cortex are the source of descending projections to the lateral geniculate nucleus (LGN) as well as a major source of axon terminals in the layers of striate cortex that receive LGN projections. This study examines how the connections of layer VI neurons are arranged with respect to the functionally distinct classes of neurons that compose their cortical and subcortical targets. By placing injections of biocytin into layer VI of tree shrew striate cortex, we identified two sublayers that differ in their intracortical and thalamic connections. Neurons in the upper part of layer VI, layer VIa, terminate in cortical layer IV, whereas those in the lower part of layer VI, layer VIb, terminate throughout the supragranular layers, layers I-III. The selectivity of layer VI subdivisions for the granular and supragranular layers is also evident in their descending projections. Neurons in layer VIa terminate preferentially in the LGN layers that supply layer IV (LGN layers 1, 2, 4, and 5), whereas neurons in layer VIb terminate in the LGN layers that supply layers I-III (LGN layers 3 and 6) and in the pulvinar nucleus. Additional subclasses of layer VIa neurons were identified based on the restriction of their terminal fields to narrow subtiers within layer IV. By influencing the activity of distinct populations of cortical neurons and the thalamic neurons that supply them, layer VI neurons could exert a powerful influence on the flow of activity in functionally distinct cortical circuits.

Original languageEnglish (US)
Pages (from-to)1203-1218
Number of pages16
JournalJournal of Neuroscience
Volume16
Issue number3
StatePublished - Feb 1 1996
Externally publishedYes

Fingerprint

Tupaiidae
Visual Cortex
Geniculate Bodies
Neurons
Pulvinar
Pyramidal Cells
Presynaptic Terminals

Keywords

  • area 17
  • corticothalamic pathways
  • lateral geniculate nucleus
  • ON, OFF pathways
  • pulvinar
  • visual cortex

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Specificity in the axonal connections of layer VI neurons in tree shrew striate cortex : Evidence for distinct granular and supragranular systems. / Usrey, William Martin; Fitzpatrick, David.

In: Journal of Neuroscience, Vol. 16, No. 3, 01.02.1996, p. 1203-1218.

Research output: Contribution to journalArticle

@article{a36d60c67dd34fb4b27ad31771136e86,
title = "Specificity in the axonal connections of layer VI neurons in tree shrew striate cortex: Evidence for distinct granular and supragranular systems",
abstract = "Pyramidal neurons in layer VI of striate cortex are the source of descending projections to the lateral geniculate nucleus (LGN) as well as a major source of axon terminals in the layers of striate cortex that receive LGN projections. This study examines how the connections of layer VI neurons are arranged with respect to the functionally distinct classes of neurons that compose their cortical and subcortical targets. By placing injections of biocytin into layer VI of tree shrew striate cortex, we identified two sublayers that differ in their intracortical and thalamic connections. Neurons in the upper part of layer VI, layer VIa, terminate in cortical layer IV, whereas those in the lower part of layer VI, layer VIb, terminate throughout the supragranular layers, layers I-III. The selectivity of layer VI subdivisions for the granular and supragranular layers is also evident in their descending projections. Neurons in layer VIa terminate preferentially in the LGN layers that supply layer IV (LGN layers 1, 2, 4, and 5), whereas neurons in layer VIb terminate in the LGN layers that supply layers I-III (LGN layers 3 and 6) and in the pulvinar nucleus. Additional subclasses of layer VIa neurons were identified based on the restriction of their terminal fields to narrow subtiers within layer IV. By influencing the activity of distinct populations of cortical neurons and the thalamic neurons that supply them, layer VI neurons could exert a powerful influence on the flow of activity in functionally distinct cortical circuits.",
keywords = "area 17, corticothalamic pathways, lateral geniculate nucleus, ON, OFF pathways, pulvinar, visual cortex",
author = "Usrey, {William Martin} and David Fitzpatrick",
year = "1996",
month = "2",
day = "1",
language = "English (US)",
volume = "16",
pages = "1203--1218",
journal = "Journal of Neuroscience",
issn = "0270-6474",
publisher = "Society for Neuroscience",
number = "3",

}

TY - JOUR

T1 - Specificity in the axonal connections of layer VI neurons in tree shrew striate cortex

T2 - Evidence for distinct granular and supragranular systems

AU - Usrey, William Martin

AU - Fitzpatrick, David

PY - 1996/2/1

Y1 - 1996/2/1

N2 - Pyramidal neurons in layer VI of striate cortex are the source of descending projections to the lateral geniculate nucleus (LGN) as well as a major source of axon terminals in the layers of striate cortex that receive LGN projections. This study examines how the connections of layer VI neurons are arranged with respect to the functionally distinct classes of neurons that compose their cortical and subcortical targets. By placing injections of biocytin into layer VI of tree shrew striate cortex, we identified two sublayers that differ in their intracortical and thalamic connections. Neurons in the upper part of layer VI, layer VIa, terminate in cortical layer IV, whereas those in the lower part of layer VI, layer VIb, terminate throughout the supragranular layers, layers I-III. The selectivity of layer VI subdivisions for the granular and supragranular layers is also evident in their descending projections. Neurons in layer VIa terminate preferentially in the LGN layers that supply layer IV (LGN layers 1, 2, 4, and 5), whereas neurons in layer VIb terminate in the LGN layers that supply layers I-III (LGN layers 3 and 6) and in the pulvinar nucleus. Additional subclasses of layer VIa neurons were identified based on the restriction of their terminal fields to narrow subtiers within layer IV. By influencing the activity of distinct populations of cortical neurons and the thalamic neurons that supply them, layer VI neurons could exert a powerful influence on the flow of activity in functionally distinct cortical circuits.

AB - Pyramidal neurons in layer VI of striate cortex are the source of descending projections to the lateral geniculate nucleus (LGN) as well as a major source of axon terminals in the layers of striate cortex that receive LGN projections. This study examines how the connections of layer VI neurons are arranged with respect to the functionally distinct classes of neurons that compose their cortical and subcortical targets. By placing injections of biocytin into layer VI of tree shrew striate cortex, we identified two sublayers that differ in their intracortical and thalamic connections. Neurons in the upper part of layer VI, layer VIa, terminate in cortical layer IV, whereas those in the lower part of layer VI, layer VIb, terminate throughout the supragranular layers, layers I-III. The selectivity of layer VI subdivisions for the granular and supragranular layers is also evident in their descending projections. Neurons in layer VIa terminate preferentially in the LGN layers that supply layer IV (LGN layers 1, 2, 4, and 5), whereas neurons in layer VIb terminate in the LGN layers that supply layers I-III (LGN layers 3 and 6) and in the pulvinar nucleus. Additional subclasses of layer VIa neurons were identified based on the restriction of their terminal fields to narrow subtiers within layer IV. By influencing the activity of distinct populations of cortical neurons and the thalamic neurons that supply them, layer VI neurons could exert a powerful influence on the flow of activity in functionally distinct cortical circuits.

KW - area 17

KW - corticothalamic pathways

KW - lateral geniculate nucleus

KW - ON, OFF pathways

KW - pulvinar

KW - visual cortex

UR - http://www.scopus.com/inward/record.url?scp=0029921452&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029921452&partnerID=8YFLogxK

M3 - Article

C2 - 8558249

AN - SCOPUS:0029921452

VL - 16

SP - 1203

EP - 1218

JO - Journal of Neuroscience

JF - Journal of Neuroscience

SN - 0270-6474

IS - 3

ER -