Eberhard R Horn

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Young fish (Oreochromis mossambicus) were exposed to microgravity (micro g) for 9 to 10 days during space missions STS-55 and STS-84, or to hypergravity (hg) for 9 days. Young animals (stages 11-12), which had not yet developed the roll-induced static vestibuloocular reflex (rVOR) at micro g- and hg-onset, and older ones (stages 14-16), which had already(More)
Experiments were performed to answer the question, whether series of generalized tonic-clonic seizures, induced in the awake rat by a local injection of Na-penicillin (PCN) solution into the motor cortex, terminates at the same critical concentration Ct of PCN within the focal area independently of the concentration C0 of PCN injected. Using the PCN(More)
In 25 rats, an intracerebral hematoma was created in the foreleg area of the motor cortex by injection of 50 microliters blood. After the lesion, 13 were treated with flunarizine and 12 with the solvent. Neurological testing was performed by measuring the running time on a rotating platform. In animals with hemiparesis, the flunarizine group (n = 7) showed(More)
UNLABELLED During space flights, tadpoles of the clawed toad Xenopus laevis occasionally develop upward bended tails (tail lordosis). The tail lordosis disappears after re-entry to 1g within a couple of days. The mechanisms responsible for the induction of the tail lordosis are unknown; physical conditions such as weight de-loading or physiological factors(More)
The effects of altered gravitational forces (AGF) on the development of the static vestibulo-ocular reflex (VOR) were investigated in Xenopus laevis tadpoles exposed to hypergravity (1.4g; 3g) or microgravity conditions (German spacelab mission D-2) for 9-10 days. The effects of light conditions during development were also tested by exposing tadpoles to(More)
In tadpoles of Xenopus laevis, the effects of microgravity on the development of the roll-induced vestibuloocular reflex (rVOR) was investigated. Special attention was focused on sensitive periods and the minimum duration of microgravity exposure by which the development of the rVOR is affected. The peak-to-peak excursion (rVOR amplitude) of the rVOR(More)
In Xenopus laevis tadpoles, we studied the static vestibuloocular reflex (rVOR) in relation to modifications of the gravitational environment to find basic mechanisms of how altered gravitational forces (AGF) affect this reflex. Animals were exposed to microgravity during space flight or hypergravity (3g) for 4 to 12 days. Basic observations were that(More)
The effects of altered gravitational conditions (AGC) on the development of the static vestibulo-ocular reflex (VOR) and readaptation to 1g were investigated in the amphibian Xenopus laevis. Tadpoles were exposed to microgravity during the German Space Mission D-2 for 10 days, using the STATEX closed survival system, or to 3g for 9 days during earth-bound(More)
Stimulus deprivation or stimulus augmentation can induce long-lasting modifications to sensory and motor systems. If deprivation is effective only during a limited period of life this phase is called "critical period." A critical period was described for the development of the roll-induced vestibuloocular reflex (rVOR) of Xenopus laevis using spaceflights.(More)