Morphometric characterization of synapses in the primate prefrontal cortex formed by afferents from the mediodorsal thalamic nucleus

L. Négyessy, P. S. Goldman-Rakic

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The main thalamic afferentation of the prefrontal cortex (PFC) originates in the mediodorsal nucleus (MD). Although it is suggested that this pathway is affected in schizophrenia, there is a lack of functional and structural data regarding its synaptic organization. The scope of this study was to characterize the ultrastructural features of thalamocortical synapses formed by afferents from the MD by applying anterograde tract tracing, immunohistochemical detection of parvalbumin (PV, a probable marker of thalamocortical endings), and quantitative electron microscopic techniques to the PFC of the macaque monkey. Our findings indicate that anterogradely-labeled and PV-immunoreactive boutons exhibit similar ultrastructural properties, characterized by their larger size, higher incidence of release sites and a higher occurrence of mitochondria when compared to non-labeled, excitatory-like endings in the middle layers of the PFC. Although most of the contacts were made on spines in both cases, PV-immunopositive axon terminals apparently targeted dendritic shafts at about twice the frequency found for anterogradely-labeled afferents from the MD (20.5% and 9.5%, respectively). This result suggests diversity among thalamocortical and/or PV-immunoreactive axon terminals of the PFC. In accordance with studies in other cortical areas, our findings suggest that corollary discharge through the mediodorsal thalamocortical projection is also adapted to synaptic transmission with high efficacy and probably exhibits marked short-term temporal dynamics in the PFC.

Original languageEnglish
Pages (from-to)148-154
Number of pages7
JournalExperimental Brain Research
Volume164
Issue number2
DOIs
Publication statusPublished - Jul 2005

Fingerprint

Mediodorsal Thalamic Nucleus
Prefrontal Cortex
Synapses
Primates
Presynaptic Terminals
Parvalbumins
Macaca
Synaptic Transmission
Haplorhini
Schizophrenia
Mitochondria
Spine
Electrons
Incidence

Keywords

  • Electron microscopy
  • Parvalbumin
  • Synaptic morphology
  • Thalamocortical
  • Tract tracing

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Morphometric characterization of synapses in the primate prefrontal cortex formed by afferents from the mediodorsal thalamic nucleus. / Négyessy, L.; Goldman-Rakic, P. S.

In: Experimental Brain Research, Vol. 164, No. 2, 07.2005, p. 148-154.

Research output: Contribution to journalArticle

@article{448a61b9a72e4d46b55f3efd996cef5b,
title = "Morphometric characterization of synapses in the primate prefrontal cortex formed by afferents from the mediodorsal thalamic nucleus",
abstract = "The main thalamic afferentation of the prefrontal cortex (PFC) originates in the mediodorsal nucleus (MD). Although it is suggested that this pathway is affected in schizophrenia, there is a lack of functional and structural data regarding its synaptic organization. The scope of this study was to characterize the ultrastructural features of thalamocortical synapses formed by afferents from the MD by applying anterograde tract tracing, immunohistochemical detection of parvalbumin (PV, a probable marker of thalamocortical endings), and quantitative electron microscopic techniques to the PFC of the macaque monkey. Our findings indicate that anterogradely-labeled and PV-immunoreactive boutons exhibit similar ultrastructural properties, characterized by their larger size, higher incidence of release sites and a higher occurrence of mitochondria when compared to non-labeled, excitatory-like endings in the middle layers of the PFC. Although most of the contacts were made on spines in both cases, PV-immunopositive axon terminals apparently targeted dendritic shafts at about twice the frequency found for anterogradely-labeled afferents from the MD (20.5{\%} and 9.5{\%}, respectively). This result suggests diversity among thalamocortical and/or PV-immunoreactive axon terminals of the PFC. In accordance with studies in other cortical areas, our findings suggest that corollary discharge through the mediodorsal thalamocortical projection is also adapted to synaptic transmission with high efficacy and probably exhibits marked short-term temporal dynamics in the PFC.",
keywords = "Electron microscopy, Parvalbumin, Synaptic morphology, Thalamocortical, Tract tracing",
author = "L. N{\'e}gyessy and Goldman-Rakic, {P. S.}",
year = "2005",
month = "7",
doi = "10.1007/s00221-005-2237-6",
language = "English",
volume = "164",
pages = "148--154",
journal = "Experimental Brain Research",
issn = "0014-4819",
publisher = "Springer Verlag",
number = "2",

}

TY - JOUR

T1 - Morphometric characterization of synapses in the primate prefrontal cortex formed by afferents from the mediodorsal thalamic nucleus

AU - Négyessy, L.

AU - Goldman-Rakic, P. S.

PY - 2005/7

Y1 - 2005/7

N2 - The main thalamic afferentation of the prefrontal cortex (PFC) originates in the mediodorsal nucleus (MD). Although it is suggested that this pathway is affected in schizophrenia, there is a lack of functional and structural data regarding its synaptic organization. The scope of this study was to characterize the ultrastructural features of thalamocortical synapses formed by afferents from the MD by applying anterograde tract tracing, immunohistochemical detection of parvalbumin (PV, a probable marker of thalamocortical endings), and quantitative electron microscopic techniques to the PFC of the macaque monkey. Our findings indicate that anterogradely-labeled and PV-immunoreactive boutons exhibit similar ultrastructural properties, characterized by their larger size, higher incidence of release sites and a higher occurrence of mitochondria when compared to non-labeled, excitatory-like endings in the middle layers of the PFC. Although most of the contacts were made on spines in both cases, PV-immunopositive axon terminals apparently targeted dendritic shafts at about twice the frequency found for anterogradely-labeled afferents from the MD (20.5% and 9.5%, respectively). This result suggests diversity among thalamocortical and/or PV-immunoreactive axon terminals of the PFC. In accordance with studies in other cortical areas, our findings suggest that corollary discharge through the mediodorsal thalamocortical projection is also adapted to synaptic transmission with high efficacy and probably exhibits marked short-term temporal dynamics in the PFC.

AB - The main thalamic afferentation of the prefrontal cortex (PFC) originates in the mediodorsal nucleus (MD). Although it is suggested that this pathway is affected in schizophrenia, there is a lack of functional and structural data regarding its synaptic organization. The scope of this study was to characterize the ultrastructural features of thalamocortical synapses formed by afferents from the MD by applying anterograde tract tracing, immunohistochemical detection of parvalbumin (PV, a probable marker of thalamocortical endings), and quantitative electron microscopic techniques to the PFC of the macaque monkey. Our findings indicate that anterogradely-labeled and PV-immunoreactive boutons exhibit similar ultrastructural properties, characterized by their larger size, higher incidence of release sites and a higher occurrence of mitochondria when compared to non-labeled, excitatory-like endings in the middle layers of the PFC. Although most of the contacts were made on spines in both cases, PV-immunopositive axon terminals apparently targeted dendritic shafts at about twice the frequency found for anterogradely-labeled afferents from the MD (20.5% and 9.5%, respectively). This result suggests diversity among thalamocortical and/or PV-immunoreactive axon terminals of the PFC. In accordance with studies in other cortical areas, our findings suggest that corollary discharge through the mediodorsal thalamocortical projection is also adapted to synaptic transmission with high efficacy and probably exhibits marked short-term temporal dynamics in the PFC.

KW - Electron microscopy

KW - Parvalbumin

KW - Synaptic morphology

KW - Thalamocortical

KW - Tract tracing

UR - http://www.scopus.com/inward/record.url?scp=23744490729&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=23744490729&partnerID=8YFLogxK

U2 - 10.1007/s00221-005-2237-6

DO - 10.1007/s00221-005-2237-6

M3 - Article

C2 - 15776222

AN - SCOPUS:23744490729

VL - 164

SP - 148

EP - 154

JO - Experimental Brain Research

JF - Experimental Brain Research

SN - 0014-4819

IS - 2

ER -