And now, a ‘newts’ story
of a different sort

Could babies born in space adapt to Earth’s gravity?

To help answer this question, Michael Wiederhold, PhD, professor of otolaryngology-head and neck surgery, and Japanese scientists sent red-bellied newts for a ride on the space shuttle Columbia. Why newts? Because these tiny salamanders have a unique breeding characteristic. After mating, the females will release their eggs only if given a hormonal signal (usually coming as the days lengthen in spring); thus, scientists can control development of offspring by giving them a hormone injection.

Dr. Wiederhold and Hugo Pedrozo, PhD, a former graduate student and now a post-doctoral fellow, have reared embryos and larvae of the saltwater mollusk, Aplysia, on a centrifuge. As the centrifuge spins, the gravitational force increases and produces the same pull one would feel while on a spinning amusement park ride.

Mollusks, like Aplysia, sense gravity with their statocysts—spherical organs with "stones" inside that sink under the pull of gravity to activate sensory cells at the bottom of the cyst. The stones were smaller and fewer, in a graded manner, in animals reared at 2-, 3- and 5-g (gravitational unit) compared to those reared at the normal 1-g while stationary on Earth.

Dr. Wiederhold also wants to study the effects of zero gravity—weightlessness. Pond snails flew in an aquatic system developed by the German space agency, DLR (Deutsche Forschungsanstalt fur Luft - und Raumfahrt e.V.), on the space shuttle flight in January and will go up again in April. The April flight is the Neurolab mission, which includes projects developed by scientists at 26 universities from seven countries.

To further study the effects of being in 1-g after rearing in zero gravity, newt larvae will be flown again in 1999, and approximately half the animals will be kept alive for several months.

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