[Study of the structure of receptor organs of the vestibular apparatus of rats after space flight on "Kosmos-1667"].
The receptor organs of the vestibular apparatus of rats flown for 7 days on Cosmos-1667 were examined. Serial sections were examined by light microscopy, some utriculus sections by electron microscopy, and otolith membranes by scanning electron microscopy. The fixation method used revealed a distinct structural heterogeneity of the receptor epithelium. In the striola area of the utriculus and sacculus as well as in the central apical area of cristae there are receptor cells surrounded by enlarged cup-like nerve endings. The nerve endings occupy over 70% of the cup-receptor cell complex. The area incorporating the enlarged nerve endings differs in size from animal to animal and from left to right ear in the same animal. The flown rat that was the first to be killed after recovery showed a very well pronounced asymmetry: in the right ear enlarged cups were seen all over the epithelium while in the left ear they were located in distinct spots. Since such changes were not identified in the remaining flown and control rats, it is concluded that they were produced by space flight effects but remained reversible and disappeared after recovery. This paper describes the causes responsible of the changes and their structural and functional relevances as well as other structural modifications that should be considered during vestibular studies.
Lychakov
D V
DV
Pashchinin
A N
AN
Boiadzhieva-Mikhaĭlova
A
A
Khristov
I
I
D000337:Aerospace Medicine; D000818:Animals; D002452:Cell Count; D008297:Male; D008854:Microscopy, Electron; D008954:Models, Biological; D051381:Rats; D012444:Saccule and Utricle / Q000294:innervation; D011984:Sensory Receptor Cells / Q000648:ultrastructure*; D013026:Space Flight; D014586:USSR; D014722:Vestibule, Labyrinth / Q000294:innervation*
Issledovanie struktury retseptornykh organov vestibuliarnogo apparata krys posle poleta na biosputnike "Kosmos-1667".