[Electron microscopy and hystology of the third ventricle ependyma of rat's brain after repeated simulation of the effects of microgravity].

ABSTRACT

Scanning electron and light microscopy were applied to study the third ventricle ependyma in rat's brain after 30-d tail-suspension, 30-d readaptation to the horizontal position, and repeated 14-d suspension in parallel with another group of rats exposed to a single 14-d suspension. Despite the repeated blood redistribution toward the head, the second tail-suspension produced significantly less grave destruction of the ependymal cell structure and cilia ultrastructure than the single 14-d or previous 30-d one, which suggests that simulation of microgravity repeated after substantial delay imparts much more persistence to the cerebrospinal fluid outflow from the brain ventricles into the saggital sinus.