| 1. |
- Gladden, M H, et al.
(author)
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Coupling between serotoninergic and noradrenergic neurones and gamma-motoneurones in the cat.
- 2000
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In: The Journal of physiology. - 0022-3751. ; 527 Pt 2, s. 213-23
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Journal article (peer-reviewed)abstract
- Noradrenaline is known to suppress transmission from group II muscle afferents when locally applied to gamma-motoneurones, and serotonin (5-HT) facilitates the transmission. The purpose of this investigation was to search for evidence of monoaminergic innervation of gamma-motoneurones. Eight gamma-motoneurones were labelled with rhodamine-dextran, and 50 micrometer thick sagittal sections of the spinal cord containing them were exposed to antibodies against dopamine beta-hydroxylase (DBH) and 5-HT. All the cells were directly and/or indirectly excited by muscle group II afferents from the muscle they innervated and/or other muscles. Appositions between monoaminergic fibres and the labelled somata and dendrites were located with three-colour confocal laser scanning microscopy by examining series of optical sections at 1 or 0.5 micrometer intervals. DBH and 5-HT varicosities formed appositions with the somata and dendrites of all the gamma-motoneurones. The mean packing densities for 5-HT (1.12 +/- 0.11 appositions per 100 micrometer(2) for somata and 0.91 +/- 0.07 per 100 micrometer(2) for dendrites) were similar to the densities of contacts reported for alpha-motoneurones. Monoaminergic varicosities in apposition to dendrites greatly outnumbered those on the somata. The density of DBH appositions was consistently lower - corresponding means were 53% and 62% of those for 5-HT on the somata and dendrites, respectively. It is concluded from an analysis of the distribution and density of varicosities in apposition to the gamma-motoneurones compared with the density in the immediate surround of the dendrites that there is indeed both a serotoninergic and noradrenergic innervation of gamma-motoneurones.
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| 2. |
- Gladden, M. H., et al.
(author)
-
Coupling between serotoninergic and noradrenergic neurones and γ-motoneurones in the cat
- 2000
-
In: Journal of Physiology. - : Wiley. - 0022-3751 .- 1469-7793. ; 527, s. 213-223
-
Journal article (peer-reviewed)abstract
- 1. Noradrenaline is known to suppress transmission from group II muscle afferents when locally applied to γ-motoneurones, and serotonin (5-HT) facilitates the transmission. The purpose of this investigation was to search for evidence of monoaminergic innervation of γ-motoneurones. 2. Eight γ-motoneurones were labelled with rhodamine-dextran, and 50 μm thick sagittal sections of the spinal cord containing them were exposed to antibodies against dopamine β-hydroxylase (DBH) and 5-HT. All the cells were directly and/or indirectly excited by muscle group II afferents from the muscle they innervated and/or other muscles. 3. Appositions between monoaminergic fibres and the labelled somata and dendrites were located with three-colour confocal laser scanning microscopy by examining series of optical sections at 1 or 0·5 μm intervals. 4. DBH and 5-HT varicosities formed appositions with the somata and dendrites of all the γ-motoneurones. The mean packing densities for 5-HT (1·12 ± 0·11 appositions per 100 μm2 for somata and 0·91 ± 0·07 per 100 μm2 for dendrites) were similar to the densities of contacts reported for α-motoneurones. Monoaminergic varicosities in apposition to dendrites greatly outnumbered those on the somata. 5. The density of DBH appositions was consistently lower - corresponding means were 53% and 62% of those for 5-HT on the somata and dendrites, respectively. 6. It is concluded from an analysis of the distribution and density of varicosities in apposition to the γ-motoneurones compared with the density in the immediate surround of the dendrites that there is indeed both a serotoninergic and noradrenergic innervation of γ-motoneurones.
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