[Effect of weightlessness on the indices of brain development (the results of pregnant rats being on the Kosmos-1514 biosatellite and research on the subsequent development of their progeny on Earth)].

Beginning from the 13th day of pregnancy the rats were under conditions of weightlessness of spaceflight for 6 days. After landing in 18-day-old fetuses the state of their brain development is investigated comparing to that in control animals, that are on the Earth. As demonstrates analysis of a number of morphological processes: reproduction, migration, neuronal differentiation, growth of processes, establishment of nervous connections, neuroglial interconnections and vascularization--all they under conditions of weightlessness develop rather fully.

[Morphogenesis of the brain of rats developing under conditions of weightlessness].

Macroscopic and light microscopic examinations of the brain of 18-day fetuses, and neonate 15-, 30- and 100- day rats whose embryonic development from day 13 to day 18 occurred in space flight on Cosmos-1514 did not reveal any changes in the brain structures of the fetuses or pups of the three ages. However, the brain of the 18-day fetuses that developed in flight showed signs of insufficient tissue oxygenation, trends toward delayed cell migration in the cortex and delayed differentiation of neurosecretory cells of the hypothalamic supraoptic nuclei. The cell differentiation rate returned to normal during continued embryogenesis after flight at 1 g.

[Enzymes in the process of neuronal differentiation of the hen spinal ganglion, spinal cord and tectum opticum. A cytophotometric histochemical study].

Changes in the activity of 13 enzymes are described in the process of cytodifferentiation of the nerve cells of spinal ganglion, the motor neurons of spinal cord and large nerve cells of the III layer of tectum opticum in 7, 10 and 21 day old chick embryos. Cytophotometry was performed with MZFV-1 (LOMO) by means of plug-method. A relatively high activity of glucose-6-phosphat dehydrogenase, diaphorase, alpha-glycerophosphate dehydrogenase and, partially, acetylcholine esterase was found already in the 7 days old embryo.