Engineering topics
Publications and source records attributed to Donovan, K..
The inner ear maculas of rats exposed to space flight for seven days were studied, and the findings are discussed. It is concluded that exposure to weightlessness for short periods of time has no morphologically detectable degenerative effect on the macular receptors. The results suggest, however, that slight increases in otoconial mass may have occurred in flight animals compared to ground-based controls.
The present ultrastructural study of serial sections has shown that type II hair cells of the anterior part of the utricular macula are integrated into the afferent neural circuitry of type I cells, which are arranged in clusters. Additionally, there exists a complex system of intramacularly originating efferent-type nerve fibers and terminals. The findings, taken together, suggest that on morphological grounds, complex processing of sensory information occurs in gravity receptors. Asymmetry of such a complex system may contribute to motion and space-motion sickness.