Fos and FRA protein expression in rat precerebellar structures during the Neurolab Space Mission.

Changes in gene expression were examined in precerebellar structures during and after space flight. These structures included the inferior olive (IO), the source of climbing fibers, and the lateral reticular nucleus (LRt) and basilar pontine nuclei (PN), sources of mossy fibers. We examined two immediate early gene products with two different time courses of expression: Fos, which persists only for a few (6-8)h after activation and FRA expression, which lasts for longer periods of time, i.

Fos and FRA protein expression in rat nucleus paragigantocellularis lateralis during different space flight conditions.

The nucleus paragigantocellularis lateralis (LPGi) exerts a prominent excitatory influence over locus coeruleus (LC) neurons, which respond to gravity signals. We investigated whether adult albino rats exposed to different gravitational fields during the NASA Neurolab Mission (STS-90) showed changes in Fos and Fos-related antigen (FRA) protein expression in the LPGi and related cardiovascular, vasomotor, and respiratory areas. Fos and FRA proteins are induced rapidly by external stimuli and return to basal levels within hours (Fos) or days (FRA) after stimulation.

Tonic gravity changes alter gene expression in the efferent vestibular nucleus.

To assess effects of tonic gravity changes on efferent vestibular neurons, immediate early gene (IEG) protein expression was compared in the efferent vestibular nucleus (EVe) of adult rats exposed to microgravity during the NASA Neurolab Mission (STS-90), and matching control animals on the ground. Rats sacrificed 1 day and 12 days after launch (experiencing approximately 0g) showed significantly fewer IEG protein-expressing cells than corresponding ground control animals (at 1 g). Normal IEG protein-expressing cell numbers reappeared within I day after flight animals returned to earth, and were maintained at 14 days after landing.