Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus.

Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus. Abstract Text:

G Ornung,O P Ottersen,S Cullheim,B Ulfhake,

The dendritic tree constitutes more than 93% of the receptive membrane area of a spinal motoneuron, yet little is known about its synaptic inputs. In this study we examined the distribution of glutamate-, GABA- and glycine-like immunoreactivity in boutons apposing dendrites in the L7 spinal cord motor nucleus, by use of postembedding immunohistochemistry on serial sections. We examined 799 boutons apposing 401 cross-sectioned dendrites of different calibre (range 0.2-15 microm), and 14 first-order (stem) dendrites. Thirty-five percent (35%) of the boutons were immunopositive for glutamate and 59% for GABA and/or glycine. Among the latter, 30% showed glycine immunoreactivity only and 24% were immunoreactive for both GABA and glycine. Very few were immunoreactive only for GABA (5%). As few as 6% of the boutons were judged as not enriched for any amino acid analysed. The fine structural characteristics of the boutons were in accordance with previous descriptions. The sample of dendrites was arranged in calibre bins in order to facilitate distribution analysis. Stem dendrites differed from the other bins, with a high total bouton covering (61%) and a high bouton density. Sixty-nine percent of the membrane covering was by glycine- and/or GABA-immunoreactive boutons, whereas 18% was covered by boutons enriched in glutamate. For non-stem dendrites, bouton covering fell from 33% to 12% with decreasing calibre. However, bouton apposition length decreased in parallel, yielding a fairly uniform bouton density among dendrites of different calibre. The lack of correlation between packing density and dendrite calibre was also evident when the sample of dendrites was broken down into subsamples based on content of amino acid immunoreactivity. The latter analysis also revealed that both the relative covering and density of boutons containing inhibitory amino acids (57%; glycine and/or GABA) and glutamate (38%), respectively, did not vary systematically with dendrite calibre. Combined, the data indicate that in non-stem dendrites the proportion of excitatory and inhibition inputs does not change systematically throughout the dendritic arborizations of spinal alpha-motoneurons. Thus, spinal motoneurons can, with respect to the general synaptic architecture, be divided into two main compartments, i.e. the proximal soma-juxtasomatic compartment (including stem dendrites) and the distal dendritic compartment. The proximal domain is under a powerful glycine and/or GABA influence. Finally, based on the data presented here and previously published data, it was calculated that spinal alpha-motoneurons receive in the range of 50-140 x 10(3) synaptic boutons.

Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus. Publishing Authors By Initials

G Ornung,OP Ottersen,S Cullheim,B Ulfhake,

For similar organic chemicals: carboxylic acids: acids, acyclic: butyric acids: aminobutyric acids: gamma-aminobutyric acid research abstracts see: organic chemicals: carboxylic acids: acids, acyclic: butyric acids: aminobutyric acids: gamma-aminobutyric acid research

PUBMED ID PMID:

MEDLINE DATE:

Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus. Journal Published:

PUBLICATION TYPE: Research Support, Non-U.S. Gov

Journal: Experimental brain research. Experimentelle Hirnfo

VOLUME: 118

Page Numbers: 517-32

Journal Abbreviation:

ISSN: 0014-4819

DAY: 15

MONTH: Feb

YEAR: 1998

Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 43312

Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus. Keywords Mesh Terms:

KEYWORDS: gamma-Aminobutyric Acid

MESH TERMS: metabolism

Chemical & Substance for Abstract: Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus. Information

Substance Name: Glutamic Acid

Registry Number: 56-86-0

Grant and Affiliation Information for Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus.

AFFILIATION: Department of Neuroscience, Karolinska Institute, Stockholm, Sweden. Goran.Ornung@neuro.ki.se

Country: GERMANY

AGENCY:

GRANT:

ACRONYM:

MEDLINETA: Exp Brain Res

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus Related Publications

• A morphometric study of the soma, first-order dendrites and proximal axon of cat lumbar alpha-motoneurones intracellularly labelled with HRP.
• Alterations in mystacial pad innervation in the aged rat.
• Anatomy of soleus alpha-motoneurone dendrites in normal cats and in cats subjected to chronic postnatal tenotomy or overload of the soleus muscle.
• Behavioral impairments of the aging rat.
• Distribution of glutamate-, glycine- and GABA-immunoreactive nerve terminals on dendrites in the cat spinal motor nucleus.
• Factors contributing to neuromuscular impairment and sarcopenia during aging.
• Glutamate and AMPA receptor immunoreactivity in Ia synapses with motoneurons and neurons of the central cervical nucleus.
• Iron load and redox stress in skeletal muscle of aged rats.
• Peripheral nerve section induces increased levels of calcitonin gene-related peptide (CGRP)-like immunoreactivity in axotomized motoneurons.