Rapid recovery of sensory function in blind cave fish treated with anemone repair proteins

Blind cave fish employ superficial neuromasts to detect currents [Baker, C.F. and J.C. Montgomery, J. Comp. Physiol. A 184 (1999) 519-527]. Briefly exposing fish to calcium-free water significantly reduces the ability of the fish to perform rheotaxis (i.e., to orient properly in currents). Spontaneous recovery to control levels of rheotaxis requires 9 days. However, if the fish are treated with fraction beta immediately after exposure to calcium-free water, recovery to control levels of rheotaxis occurs within 1.3 h, the first time point tested. Fraction beta is a chromatographic fraction of 'repair proteins' isolated from sea anemones. The benefits of fraction beta on restoring rheotaxis exhibit dose dependency with the minimum effective dose estimated at 1 ng/ml. Exogenously supplied ATP augments the efficacy of fraction beta. Such augmentation is abolished by PPADS, an inhibitor of purinoceptors. Immunocytochemistry confirms the presence of purinoceptors in superficial neuromasts. The present results suggest that 'repair proteins' obtained from anemones significantly augment intrinsic repair mechanisms in fish. Furthermore, the data obtained in the fish system strongly parallel our previously published findings on sea anemones, raising the possibility that mechanisms of hair bundle repair may be evolutionarily conserved.