Fine structures of perikaryal myelin sheaths on statoacoustic ganglion cells in 3-day-old chicks.
Perikaryal myelin sheaths on statoacoustic ganglion cells in 3-day-old chicks were studied by electron microscopy. The fixation method with a high-concentrated warm fixative helped in successful demonstrations of perikaryal myelin structures. The sheaths were composed of loose and compact myelin mixed by various arrangements. Twenty-seven percent of perikarya were entirely encircled by compact myelin, 71% were partly wrapped by compact myelin, and 2% were wrapped by just loose myelin. The perikaryal myelin was composed of 3 to 16 layers of loose and compact lamellae, whereas the axonal myelin of 10 to 28 of compact lamellae. Since no unmyelinated perikarya, which are covered by a single layer of Schwann cell cytoplasm, were detected, it is suggested that the perikarya myelination on all the ganglion cells has started before 3 days after hatching.
Sun
Y J
YJ
Department of Anatomy, Shinshu University School of Medicine, Matsumoto, Japan.
Komatsu
S
S
Naito
A
A
Watanabe
S Y
SY
D000818:Animals; D002645:Chickens; D003593:Cytoplasm / Q000648:ultrastructure; D006652:Histological Techniques; D008854:Microscopy, Electron; D009186:Myelin Sheath / Q000648:ultrastructure*; D009474:Neurons / Q000166:cytology / Q000648:ultrastructure; D013136:Spiral Ganglion / Q000166:cytology* / Q000648:ultrastructure*