14. - E. N. Grigoryan*, H. J. Anton**, and V. 1. Mitashov* (November 1998).
Microgravity effects on neural retina regeneration in the newt after retina detachment
(*Institute of Developmental Biology Russian Academy of Sciences, Moscow, Russia; ** Zoologisches Institut, Universität zu Köln, D-50996 Germany )
From experiments on limb and eye lens regeneration in urodeles under spaceflight conditions (SFC) it is evident that SFC rather stimulates regeneration than inhibits it. To investigate comprehensively neural regeneration under SFC, an original model experiment is proposed. The initial results described here concern neural retina regeneration in newts (Pleurodeles waltl) exposed to microgravity simulated in a radial clinostat. After clinorotation for seven days (until post-operation-day 16), a positive effect on structural restoration of detached neural retina was confirmed by different criteria. In detail, an increased number of Müllerian glial cells, an increased relative volume of the plexiform layers, reduced cell death, advanced redifferentiation of retinal pigment epithelium, and extended areas of neural retina reattachment were detected in the rotated newts. Moreover, cell proliferation in the inner nuclear layer of the neural retina increased as compared with control. Thus, simulated low gravity appears to intensify natural cytological and molecular mechanisms of neural retina regeneration in lower vertebrates (E. N. Grigoryan, H. J. Anton, and V. 1. Mitashov, 1998, Adv. Space Res. Vol. 22, 293-301).