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The pre- and post-somatic segments of the human type I spiral ganglion neurons--structural and functional considerations related to cochlear implantation.

Liu W, Edin F, Atturo F, Rieger G, Löwenheim H, Senn P, Blumer M, Schrott-Fischer A, Rask-Andersen H, Glueckert R - Neuroscience (2014)

Bottom Line: These segments were found surrounded by non-myelinated Schwann cells (NMSCs) showing strong intracellular expression of laminin-β2/collagen IV.Their BMs express laminin-β2/collagen IV and reaches the BM of the sensory epithelium at the habenula perforata.We speculate that the NMSCs protect SGNs from further degeneration following dendrite loss.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden; Department of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden. Electronic address: lwoo24@gmail.com.

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Graphic showing different neuro-anatomical conditions in patients with sensorineural hearing loss. C could be prevalent in cochlear implant patients with long deafness duration. (A) Normal condition. The SGNs are surrounded by satellite glial cells (SGCs) while the pre- and post-somatic axonal segments are bordered by non-myelinated Schwann cells (NMSCs). Axons are enwrapped by regular Schwann cells. (B) Deafness is frequently caused by a loss of functional hair cells. Preservation of supporting cells can up-hold the integrity of the peripheral dendrite. (C) Loss of sensory and supporting cells may result in dendrite atrophy (Teufert et al., 2007) due to retrograde degeneration. The unmyelinated bordering cells such as SGCs and NMSCs may consolidate neurons as mono-polar or “amputated” cells (arrow) with unbroken connections to the brain stem. Theoretically, these neurons could be re-sprouted.
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f0040: Graphic showing different neuro-anatomical conditions in patients with sensorineural hearing loss. C could be prevalent in cochlear implant patients with long deafness duration. (A) Normal condition. The SGNs are surrounded by satellite glial cells (SGCs) while the pre- and post-somatic axonal segments are bordered by non-myelinated Schwann cells (NMSCs). Axons are enwrapped by regular Schwann cells. (B) Deafness is frequently caused by a loss of functional hair cells. Preservation of supporting cells can up-hold the integrity of the peripheral dendrite. (C) Loss of sensory and supporting cells may result in dendrite atrophy (Teufert et al., 2007) due to retrograde degeneration. The unmyelinated bordering cells such as SGCs and NMSCs may consolidate neurons as mono-polar or “amputated” cells (arrow) with unbroken connections to the brain stem. Theoretically, these neurons could be re-sprouted.

Mentions: Fluorescent and confocal IHC combined with TEM of well-fixed human cochleae, seem to demonstrate a distinct type of perineural cell surrounding the initial segments of the type I SGNs. Unlike the SGCs, they showed a rich intracellular expression of laminin-β2 and collagen IV. They lacked myelin and MBP expression and we named these cells NMSCs. The nuclear shape was similar to the myelinated Schwann cells and their cell coat displayed frequently villous-like protrusions bordered by a foliated BM. These phenotypic manifestations suggest that it may represent a cell with unique functional properties (Fig. 8).


The pre- and post-somatic segments of the human type I spiral ganglion neurons--structural and functional considerations related to cochlear implantation.

Liu W, Edin F, Atturo F, Rieger G, Löwenheim H, Senn P, Blumer M, Schrott-Fischer A, Rask-Andersen H, Glueckert R - Neuroscience (2014)

Graphic showing different neuro-anatomical conditions in patients with sensorineural hearing loss. C could be prevalent in cochlear implant patients with long deafness duration. (A) Normal condition. The SGNs are surrounded by satellite glial cells (SGCs) while the pre- and post-somatic axonal segments are bordered by non-myelinated Schwann cells (NMSCs). Axons are enwrapped by regular Schwann cells. (B) Deafness is frequently caused by a loss of functional hair cells. Preservation of supporting cells can up-hold the integrity of the peripheral dendrite. (C) Loss of sensory and supporting cells may result in dendrite atrophy (Teufert et al., 2007) due to retrograde degeneration. The unmyelinated bordering cells such as SGCs and NMSCs may consolidate neurons as mono-polar or “amputated” cells (arrow) with unbroken connections to the brain stem. Theoretically, these neurons could be re-sprouted.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4300406&req=5

f0040: Graphic showing different neuro-anatomical conditions in patients with sensorineural hearing loss. C could be prevalent in cochlear implant patients with long deafness duration. (A) Normal condition. The SGNs are surrounded by satellite glial cells (SGCs) while the pre- and post-somatic axonal segments are bordered by non-myelinated Schwann cells (NMSCs). Axons are enwrapped by regular Schwann cells. (B) Deafness is frequently caused by a loss of functional hair cells. Preservation of supporting cells can up-hold the integrity of the peripheral dendrite. (C) Loss of sensory and supporting cells may result in dendrite atrophy (Teufert et al., 2007) due to retrograde degeneration. The unmyelinated bordering cells such as SGCs and NMSCs may consolidate neurons as mono-polar or “amputated” cells (arrow) with unbroken connections to the brain stem. Theoretically, these neurons could be re-sprouted.
Mentions: Fluorescent and confocal IHC combined with TEM of well-fixed human cochleae, seem to demonstrate a distinct type of perineural cell surrounding the initial segments of the type I SGNs. Unlike the SGCs, they showed a rich intracellular expression of laminin-β2 and collagen IV. They lacked myelin and MBP expression and we named these cells NMSCs. The nuclear shape was similar to the myelinated Schwann cells and their cell coat displayed frequently villous-like protrusions bordered by a foliated BM. These phenotypic manifestations suggest that it may represent a cell with unique functional properties (Fig. 8).

Bottom Line: These segments were found surrounded by non-myelinated Schwann cells (NMSCs) showing strong intracellular expression of laminin-β2/collagen IV.Their BMs express laminin-β2/collagen IV and reaches the BM of the sensory epithelium at the habenula perforata.We speculate that the NMSCs protect SGNs from further degeneration following dendrite loss.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden; Department of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden. Electronic address: lwoo24@gmail.com.

Show MeSH
Related in: MedlinePlus