The effect of neonatal 6-hydroxydopamine treatment on synaptogenesis in the visual cortex of the rat

Mary E Blue, J. G. Parnavelas

Research output: Contribution to journalArticle

Abstract

It has been been proposed repeatedly that the noradrenergic (NE) system may exert an influence on cortical development. We have tested this proposition by examining synaptogenesis in the visual cortex of rats whose NE afferents were selectively lesioned by injections of the neurotoxin 6-hydroxydopamine (6-OHDA). Control littermates were injected with equal volumes of vehicle. Montages of electron micrographs covering approximately 50 μm-wide strips of cortex were assembled from both groups of animals at 2,4,6,8,14 and 90 days of age. Synapse counts revealed a significantly higher density of synapses in the cortex of 6-OHDA-treated rats during the first week of postnatal life. The difference between the experimental and control rats was less apparent during the second postnatal week, and at day 90 the densities of synapses were similar for the two groups of animals. The enhanced density, which was the result of the increased number of Gray's type I synapses, was confined to the subplate region at day 2 but became more widespread in the cortex at subsequent stages of development. From these observations it would appear that the NE system exerts an inhibitory influence on synapse formation in the visual cortex in early postnatal life.

Original languageEnglish (US)
Pages (from-to)199-205
Number of pages7
JournalJournal of Comparative Neurology
Volume205
Issue number2
StatePublished - 1982
Externally publishedYes

Fingerprint

Oxidopamine
Visual Cortex
Synapses
Therapeutics
Neurotoxins
Electrons
Injections

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

The effect of neonatal 6-hydroxydopamine treatment on synaptogenesis in the visual cortex of the rat. / Blue, Mary E; Parnavelas, J. G.

In: Journal of Comparative Neurology, Vol. 205, No. 2, 1982, p. 199-205.

Research output: Contribution to journalArticle

@article{b1f30f1fcacb431ebb1b5ebfb8e020d0,
title = "The effect of neonatal 6-hydroxydopamine treatment on synaptogenesis in the visual cortex of the rat",
abstract = "It has been been proposed repeatedly that the noradrenergic (NE) system may exert an influence on cortical development. We have tested this proposition by examining synaptogenesis in the visual cortex of rats whose NE afferents were selectively lesioned by injections of the neurotoxin 6-hydroxydopamine (6-OHDA). Control littermates were injected with equal volumes of vehicle. Montages of electron micrographs covering approximately 50 μm-wide strips of cortex were assembled from both groups of animals at 2,4,6,8,14 and 90 days of age. Synapse counts revealed a significantly higher density of synapses in the cortex of 6-OHDA-treated rats during the first week of postnatal life. The difference between the experimental and control rats was less apparent during the second postnatal week, and at day 90 the densities of synapses were similar for the two groups of animals. The enhanced density, which was the result of the increased number of Gray's type I synapses, was confined to the subplate region at day 2 but became more widespread in the cortex at subsequent stages of development. From these observations it would appear that the NE system exerts an inhibitory influence on synapse formation in the visual cortex in early postnatal life.",
author = "Blue, {Mary E} and Parnavelas, {J. G.}",
year = "1982",
language = "English (US)",
volume = "205",
pages = "199--205",
journal = "Journal of Comparative Neurology",
issn = "0021-9967",
publisher = "Wiley-Liss Inc.",
number = "2",

}

TY - JOUR

T1 - The effect of neonatal 6-hydroxydopamine treatment on synaptogenesis in the visual cortex of the rat

AU - Blue, Mary E

AU - Parnavelas, J. G.

PY - 1982

Y1 - 1982

N2 - It has been been proposed repeatedly that the noradrenergic (NE) system may exert an influence on cortical development. We have tested this proposition by examining synaptogenesis in the visual cortex of rats whose NE afferents were selectively lesioned by injections of the neurotoxin 6-hydroxydopamine (6-OHDA). Control littermates were injected with equal volumes of vehicle. Montages of electron micrographs covering approximately 50 μm-wide strips of cortex were assembled from both groups of animals at 2,4,6,8,14 and 90 days of age. Synapse counts revealed a significantly higher density of synapses in the cortex of 6-OHDA-treated rats during the first week of postnatal life. The difference between the experimental and control rats was less apparent during the second postnatal week, and at day 90 the densities of synapses were similar for the two groups of animals. The enhanced density, which was the result of the increased number of Gray's type I synapses, was confined to the subplate region at day 2 but became more widespread in the cortex at subsequent stages of development. From these observations it would appear that the NE system exerts an inhibitory influence on synapse formation in the visual cortex in early postnatal life.

AB - It has been been proposed repeatedly that the noradrenergic (NE) system may exert an influence on cortical development. We have tested this proposition by examining synaptogenesis in the visual cortex of rats whose NE afferents were selectively lesioned by injections of the neurotoxin 6-hydroxydopamine (6-OHDA). Control littermates were injected with equal volumes of vehicle. Montages of electron micrographs covering approximately 50 μm-wide strips of cortex were assembled from both groups of animals at 2,4,6,8,14 and 90 days of age. Synapse counts revealed a significantly higher density of synapses in the cortex of 6-OHDA-treated rats during the first week of postnatal life. The difference between the experimental and control rats was less apparent during the second postnatal week, and at day 90 the densities of synapses were similar for the two groups of animals. The enhanced density, which was the result of the increased number of Gray's type I synapses, was confined to the subplate region at day 2 but became more widespread in the cortex at subsequent stages of development. From these observations it would appear that the NE system exerts an inhibitory influence on synapse formation in the visual cortex in early postnatal life.

UR - http://www.scopus.com/inward/record.url?scp=0020073517&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0020073517&partnerID=8YFLogxK

M3 - Article

C2 - 6804536

AN - SCOPUS:0020073517

VL - 205

SP - 199

EP - 205

JO - Journal of Comparative Neurology

JF - Journal of Comparative Neurology

SN - 0021-9967

IS - 2

ER -