Sprouting of non-sympathetic myelinated and unmyelinated fibres in response to chronic sympathetic denervation in the pineal gland of the Chinese hamster, Cricetulus griseus.
We have examined the effects of chronic sympathetic denervation on non-sympathetic myelinated and unmyelinated fibres in the superficial pineal gland of the Chinese hamster (Cricetulus griseus), using LM, EM and immunohistochemistry. The results suggest that non-sympathetic, myelinated and unmyelinated fibres enter the superficial pineal gland at its distal portion by way of the nervi conarii, and that these fibres are immunoreactive for calcitonin gene-related peptide or substance P. Non-sympathetic, myelinated and unmyelinated fibres in the superficial pineal gland increased in number following chronic superior cervical ganglionectomy. The number of unmyelinated fibres in the nervi conarii also increased in ganglionectomized animals. Thus, the numerical increase of calcitonin gene-related peptide or substance P fibres found in the superficial pineal gland after long-term sympathectomy may be due to sprouting of these fibres. It is speculated that the growth of non-sympathetic, myelinated and unmyelinated fibres and myelination of the former fibres occurring after sympathectomy are caused by nerve growth factor-related mechanisms.
Matsushima
S
S
Department of Anatomy, Asahikawa Medical College, Japan.
Sakai
Y
Y
Hira
Y
Y
D000818:Animals; D015415:Biomarkers / Q000032:analysis; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D006224:Cricetinae; D003412:Cricetulus; D003714:Denervation; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D009412:Nerve Fibers / Q000502:physiology / Q000648:ultrastructure*; D009413:Nerve Fibers, Myelinated / Q000502:physiology / Q000648:ultrastructure*; D009416:Nerve Regeneration; D010870:Pineal Gland / Q000166:cytology* / Q000502:physiology* / Q000648:ultrastructure; D013373:Substance P / Q000032:analysis; D017783:Superior Cervical Ganglion / Q000502:physiology*; D013997:Time Factors
D015415:Biomarkers; D013373:Substance P; D015740:Calcitonin Gene-Related Peptide