Dv. Lychakov et al., SWELLING OF CALYX-LIKE NERVE-ENDINGS IN MACULAE AND CRISTAE OF QUAIL EMBRYOS EXPOSED TO WEIGHTLESSNESS, ACT VET B, 62, 1993, pp. 190000031-190000034
The results of our morphological analysis show that the vestibular app
aratus of quail embryos, that developed in weightlessness from 1-12 da
ys age, are formed normally. Thus, the specific stimulus of gravity is
apparently not a prerequisite of the formation of the structural orga
nization of the vestibular apparatus at the early stages of ontogenesi
s of the lower and higher vertebrates. However, the space flight facto
rs can produce some structural modifications in the otolithic organ an
d cristae. Light microscopy revealed a marked swelling of calyx-like n
erve endings throughout the sensory epithelium. We suggest that ionic
changes in inner ear could cause the swelling of these nerve calyces.
We suppose that these rearrangements arise only after weightlessness a
nd/or a strong sensory cell stimulation.