Sethi M.,Maulana Azad Medical College Anatomy |
Mishra S.,Maulana Azad Medical College Anatomy |
Kaul J.M.,Maulana Azad Medical College Anatomy |
Vasudeva N.,Maulana Azad Medical College Anatomy
Journal of Morphological Sciences | Year: 2013
A light microscopic study of the cochlear ganglion development at various stages of gestation was conducted in human fetuses to understand its morphological maturation with particular emphasis on synaptogenesis. Knowledge of development of the peripheral auditory system especially the cochlea and the cochlear ganglion contributes to understanding the effects of ototoxic insults on hearing function. Ten aborted fetuses from 14th to 28th weeks of gestation were procured from Department of Obstetrics and Gynaecology, LN Hospital after obtaining ethical clearance and were analyzed under light microscopy. Evidence of synaptogenesis was demonstrated by using an Immunohistochemical stain for Synaptophysin, a 38kD integral membrane protein of synaptic vesicles. A progressive increase in neuronal size was revealed from 16th to 28th weeks of gestation. At 20th weeks gestation, neuronal processes and the soma were surrounded by supporting cells giving a honeycombed pattern. Myelinated neuronal processes were seen using Luxol fast Blue stain by 24wks of gestation, however, the perikarya showed surrounding myelination at 28th weeks in some of the neurons. The expression of Synaptophysin in cytoplasm and nerve fibers grew stronger gradually from 20th weeks till 28th weeks of gestation. Thus maturation of human cochlear ganglion commences from mid gestation and almost an adult pattern was seen at 28th weeks.