ISSN:
1432-0568
Keywords:
Nerve growth factor
;
NGF receptors
;
Cochlear ganglion
;
Vestibular ganglion
;
Radioautography
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary We have previously demonstrated the presence of specific receptors for nerve growth factor (NGF) in cochleovestibular ganglia of 72 h (stage 19–20) quail embryos, with a greater density of NGF receptors in the cochlear portion of the ganglion. The present study was conducted to determine the temporal pattern of NGF receptor expression in cochlear and vestibular ganglia throughout development, and was conducted in two species, quail and mouse. As in the quail, specific binding of125I-NGF was detected in cochleovestibular ganglia of mouse embryos from an embryonic age equivalent to 72 h quail embryos (embryonic day 11, E11), with a similar concentration of125I-NGF binding in the cochlear portion. Quantitative studies revealed that125I-NGF binding continued to increase, in both cochlear and vestibular ganglia, for several days of development, and then began to decrease to minimal levels. Maximal levels were achieved at E7 in the quail, and E14 to E16 in the mouse, while minimal levels were reached by E13 in the quail, and E18 in the mouse. The level of125I-NGF binding in cochlear ganglia was two to three times higher than in vestibular ganglia; a finding corroborated by radioautographic studies. In both quail and mouse, NGF receptors were more heavily concentrated in the ventromedial portion of the cochlear ganglion, adjacent to the cochlear duct; an area containing both support cells and peripheral neuronal processes. In the vestibular ganglion,125I-NGF binding was more homogeneous, although small areas containing high densities of silver grains were observed. The presence of NGF receptors in cochlear and vestibular ganglia suggests that these ganglia may be responsive to and/or dependent upon NGF during their development.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01236048
