Hypergravity effects on succinate dehydrogenase reactivity in fish vestibular ganglia Original Research Article

Larval cichlid fish (Oreochromis mossambicus) were kept at 3g hypergravity (centrifuge) for 14 or 21 days. Subsequently, succinate dehydrogenase reactivity was histochemically demonstrated and densitometrically determined in the gangliones utricularis and saccularis as well as (for control) in the diencephalic, non-vestibular Nucleus glomerulosus posterioris. It was found that succinate dehydrogenase reactivity within the ganglion utricularis was significantly increased in experimental animals as compared to the 1g controls (p < 0.05 and p < 0.01 after 14 and 21 days of hypergravity, respectively), whereas hypergravity had no effect on succinate dehydrogenase reactivity in the ganglion saccularis and in the Nucleus glomerulosus posterioris. This result clearly indicates that hypergravity exclusively affects the metabolic activity of a ganglion, which is directly involved in the transmission of gravity inputs.