Free-floating cells in the endolymphatic sac after surgical utricular nerve section.

Free-floating cells (FFC) in endolymphatic sac (ES) were microscopically examined, counted, and statistically studied in 8 squirrel monkeys after the unilateral section of the utricular nerve (UNS). After the operation these monkeys were kept for 17-38 days until the acquisition of functional (locomotor balance) compensation was completed. The result showed twice more FFC in the ES on the operated side, than those on the nonoperated side. The result showed a significant increase (p less than 0.05) of FFC in the ES under the pathological condition with autogenous debris in the endolymphatic space, and proved the existence of some reactive role of the ES to the labyrinthine insult.