Morphological and morphometric study on human Scarpa ganglion development

Gangliformis Intumescentia and Beyond: Antonio Scarpa and His Core Contribution to Neuroanatomy, Neurosurgery, and Otoneurosurgery

Nearly 250 years ago, Antonio Scarpa became a professor of anatomy and surgery only 2 years after he graduated from the University of Padua. The young lecturer soon became one of the most renowned anatomists in Italy and a director of the Faculty of Medicine at the University of Pavia. He worked in the fields of general surgery and ophthalmology. Several anatomic structures have been named after him, mainly Scarpa fascia and Scarpa triangle. His interest in neuroanatomy was ardent, despite being occasionally neglected. Scarpa's contributions to the fields of neurosciences have been significant. He was the first to describe the round window and the secondary tympanic membrane, and he eventually focused on the auditory and olfactory organs. Notably, the vestibular ganglion is now known as Scarpa ganglion. Scarpa's magnum opus was the book Tabulae Neurologicae, in which he described the path of several cranial nerves including the vagus nerve and innervation of the heart. Since his death in 1832, Scarpa's head has been preserved at the University History Museum of the University of Pavia. In this historical vignette, we aim to describe Antonio Scarpa's troubled life and brilliant career, focusing on his core contributions to neuroanatomy, neurosurgery, and otoneurosurgery.

A comparative morphologic and morphometric study about geniculate ganglion development in man and in rat

CONCLUSIONS

Human-rat geniculate ganglion (GG) have multiple origins: (1) An initial proximity (20 μm) to the endocranial foramen of the IAM, suggests neural crest induction; and (2) The influence of epibranchial placodes: the tensor tympani muscle (TTM) and the otic apical coil.

OBJECTIVES

This study was undertaken to determine the comparative development of human-rat GG.

MATERIALS AND METHODS

A light microscopic study of the GG in human material obtained from spontaneous abortions at 9, 13, 14, 17, 18, and 30 weeks, and one neonate was done. This study examined Webster rat embryos and a post-natal series. Specimens were fixed in Bouin fluid, embedded in paraffin, cut, and stained with H&E. The histomorphometric data were obtained with image analysis software.

RESULTS

The human fetus of 9 weeks presents two neuronal groups in the VII nerve: one near (20 μm) the IAM endocranial foramen, foraminal, and the other, tympanic. Neonate GG is located between the TTM and the cochlear apex (inwards). In the 16 day old rat embryo GG is placed within a canal containing the stapedial artery. In the adult rat the GG and the stapedial artery are placed within the IAM.