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Polysialylated-neural cell adhesion molecule (PSA-NCAM) in the human trigeminal ganglion and brainstem at prenatal and adult ages.

Quartu M, Serra MP, Boi M, Ibba V, Melis T, Del Fiacco M - BMC Neurosci (2008)

Bottom Line: In specimens of different age, the distribution pattern remains fairly steady, whereas the density of immunoreactive structures and the staining intensity may change and are usually higher in newborn than in adult specimens.The results obtained show that, in man, the expression of PSA-NCAM in selective populations of central and peripheral neurons occurs not only during prenatal life, but also in adulthood.They support the concept of an involvement of this molecule in the structural and functional neural plasticity throughout life.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Cytomorphology, University of Cagliari, Cittadella Universitaria di Monserrato, Monserrato (Cagliari), Italy. quartu@unica.it

ABSTRACT

Background: The polysialylated neuronal cell adhesion molecule (PSA-NCAM) is considered a marker of developing and migrating neurons and of synaptogenesis in the immature vertebrate nervous system. However, it persists in the mature normal brain in some regions which retain a capability for morphofunctional reorganization throughout life. With the aim of providing information relevant to the potential for dynamic changes of specific neuronal populations in man, this study analyses the immunohistochemical occurrence of PSA-NCAM in the human trigeminal ganglion (TG) and brainstem neuronal populations at prenatal and adult age.

Results: Western blot analysis in human and rat hippocampus supports the specificity of the anti-PSA-NCAM antibody and the immunodetectability of the molecule in postmortem tissue. Immunohistochemical staining for PSA-NCAM occurs in TG and several brainstem regions during prenatal life and in adulthood. As a general rule, it appears as a surface staining suggestive of membrane labelling on neuronal perikarya and proximal processes, and as filamentous and dot-like elements in the neuropil. In the TG, PSA-NCAM is localized to neuronal perikarya, nerve fibres, pericellular networks, and satellite and Schwann cells; further, cytoplasmic perikaryal staining and positive pericellular fibre networks are detectable with higher frequency in adult than in newborn tissue. In the adult tissue, positive neurons are mostly small- and medium-sized, and amount to about 6% of the total ganglionic population. In the brainstem, PSA-NCAM is mainly distributed at the level of the medulla oblongata and pons and appears scarce in the mesencephalon. Immunoreactivity also occurs in discretely localized glial structures. At all ages examined, PSA-NCAM occurs in the spinal trigeminal nucleus, solitary nuclear complex, vestibular and cochlear nuclei, reticular formation nuclei, and most of the precerebellar nuclei. In specimens of different age, the distribution pattern remains fairly steady, whereas the density of immunoreactive structures and the staining intensity may change and are usually higher in newborn than in adult specimens.

Conclusion: The results obtained show that, in man, the expression of PSA-NCAM in selective populations of central and peripheral neurons occurs not only during prenatal life, but also in adulthood. They support the concept of an involvement of this molecule in the structural and functional neural plasticity throughout life. In particular, the localization of PSA-NCAM in TG primary sensory neurons likely to be involved in the transmission of protopathic stimuli suggests the possible participation of this molecule in the processing of the relevant sensory neurotransmission.

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Size frequency histogram of PSA-NCAM immunoreactive neurons in human trigeminal ganglion from an adult subject (case 5). Cells present in 6 sections were measured. x-Axis values represent the mean cell diameters expressed in μm; y-axis reports values of relative percent frequency. Curve superimposed on the histogram represent the theoretical normal distribution.
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Figure 4: Size frequency histogram of PSA-NCAM immunoreactive neurons in human trigeminal ganglion from an adult subject (case 5). Cells present in 6 sections were measured. x-Axis values represent the mean cell diameters expressed in μm; y-axis reports values of relative percent frequency. Curve superimposed on the histogram represent the theoretical normal distribution.

Mentions: In adult tissue, several neurons show a peripheral immunoreactivity suggestive of membrane labelling (Figure 3A,B). However, a number of them seem surrounded by immunostained satellite cells (Figure 3C,F), which makes it difficult to unequivocally identify a membrane staining and to ascertain a neuronal labelling. On the other hand, a number of perikarya also show a cytoplasmic labelling, thus allowing a morphometric analysis. This was done considering only the cell sections where both staining of the cytoplasmic compartment and the nucleus were clearly detectable, such as those indicated by arrows in Figure 3A,B. In the TG specimen from an adult subject (case 6), they amount to about 6.4 ± 0.075% of the total ganglionic population. Frequency histogram of those neurons is shown in Figure 4. About 70% of the sized neurons have a mean cell diameter ranging from 22 μm to 34 μm, thus falling in the class of small- and medium-sized cells, whereas the remaining of them fall in the large size range. Varicose fibres may be found either isolated or as bundles of variable density (Figure 3A–C). A few non immunolabelled neuronal cell bodies appear surrounded by immunoreactive varicose nerve fibres (Figure 3D,E).


Polysialylated-neural cell adhesion molecule (PSA-NCAM) in the human trigeminal ganglion and brainstem at prenatal and adult ages.

Quartu M, Serra MP, Boi M, Ibba V, Melis T, Del Fiacco M - BMC Neurosci (2008)

Size frequency histogram of PSA-NCAM immunoreactive neurons in human trigeminal ganglion from an adult subject (case 5). Cells present in 6 sections were measured. x-Axis values represent the mean cell diameters expressed in μm; y-axis reports values of relative percent frequency. Curve superimposed on the histogram represent the theoretical normal distribution.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2612005&req=5

Figure 4: Size frequency histogram of PSA-NCAM immunoreactive neurons in human trigeminal ganglion from an adult subject (case 5). Cells present in 6 sections were measured. x-Axis values represent the mean cell diameters expressed in μm; y-axis reports values of relative percent frequency. Curve superimposed on the histogram represent the theoretical normal distribution.
Mentions: In adult tissue, several neurons show a peripheral immunoreactivity suggestive of membrane labelling (Figure 3A,B). However, a number of them seem surrounded by immunostained satellite cells (Figure 3C,F), which makes it difficult to unequivocally identify a membrane staining and to ascertain a neuronal labelling. On the other hand, a number of perikarya also show a cytoplasmic labelling, thus allowing a morphometric analysis. This was done considering only the cell sections where both staining of the cytoplasmic compartment and the nucleus were clearly detectable, such as those indicated by arrows in Figure 3A,B. In the TG specimen from an adult subject (case 6), they amount to about 6.4 ± 0.075% of the total ganglionic population. Frequency histogram of those neurons is shown in Figure 4. About 70% of the sized neurons have a mean cell diameter ranging from 22 μm to 34 μm, thus falling in the class of small- and medium-sized cells, whereas the remaining of them fall in the large size range. Varicose fibres may be found either isolated or as bundles of variable density (Figure 3A–C). A few non immunolabelled neuronal cell bodies appear surrounded by immunoreactive varicose nerve fibres (Figure 3D,E).

Bottom Line: In specimens of different age, the distribution pattern remains fairly steady, whereas the density of immunoreactive structures and the staining intensity may change and are usually higher in newborn than in adult specimens.The results obtained show that, in man, the expression of PSA-NCAM in selective populations of central and peripheral neurons occurs not only during prenatal life, but also in adulthood.They support the concept of an involvement of this molecule in the structural and functional neural plasticity throughout life.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Cytomorphology, University of Cagliari, Cittadella Universitaria di Monserrato, Monserrato (Cagliari), Italy. quartu@unica.it

ABSTRACT

Background: The polysialylated neuronal cell adhesion molecule (PSA-NCAM) is considered a marker of developing and migrating neurons and of synaptogenesis in the immature vertebrate nervous system. However, it persists in the mature normal brain in some regions which retain a capability for morphofunctional reorganization throughout life. With the aim of providing information relevant to the potential for dynamic changes of specific neuronal populations in man, this study analyses the immunohistochemical occurrence of PSA-NCAM in the human trigeminal ganglion (TG) and brainstem neuronal populations at prenatal and adult age.

Results: Western blot analysis in human and rat hippocampus supports the specificity of the anti-PSA-NCAM antibody and the immunodetectability of the molecule in postmortem tissue. Immunohistochemical staining for PSA-NCAM occurs in TG and several brainstem regions during prenatal life and in adulthood. As a general rule, it appears as a surface staining suggestive of membrane labelling on neuronal perikarya and proximal processes, and as filamentous and dot-like elements in the neuropil. In the TG, PSA-NCAM is localized to neuronal perikarya, nerve fibres, pericellular networks, and satellite and Schwann cells; further, cytoplasmic perikaryal staining and positive pericellular fibre networks are detectable with higher frequency in adult than in newborn tissue. In the adult tissue, positive neurons are mostly small- and medium-sized, and amount to about 6% of the total ganglionic population. In the brainstem, PSA-NCAM is mainly distributed at the level of the medulla oblongata and pons and appears scarce in the mesencephalon. Immunoreactivity also occurs in discretely localized glial structures. At all ages examined, PSA-NCAM occurs in the spinal trigeminal nucleus, solitary nuclear complex, vestibular and cochlear nuclei, reticular formation nuclei, and most of the precerebellar nuclei. In specimens of different age, the distribution pattern remains fairly steady, whereas the density of immunoreactive structures and the staining intensity may change and are usually higher in newborn than in adult specimens.

Conclusion: The results obtained show that, in man, the expression of PSA-NCAM in selective populations of central and peripheral neurons occurs not only during prenatal life, but also in adulthood. They support the concept of an involvement of this molecule in the structural and functional neural plasticity throughout life. In particular, the localization of PSA-NCAM in TG primary sensory neurons likely to be involved in the transmission of protopathic stimuli suggests the possible participation of this molecule in the processing of the relevant sensory neurotransmission.

Show MeSH
Related in: MedlinePlus