Inhibition of mTOR by Rapamycin Results in Auditory Hair Cell Damage and Decreased Spiral Ganglion Neuron Outgrowth and Neurite Formation In Vitro

Figure 4

Effect of rapamycin on SG explants and their supporting cells. (a–c) Representative SG explants stained with anti-200 kDa neurofilament antibody after treatment with DMSO (control), 10 μM rapamycin, and 100 μM rapamycin. Scale bar 300 μm. (d) Average number of SG neurites observed per SG explant. The numbers of neurites observed in control samples are compared to those seen with two different concentrations of rapamycin. Rapamycin-treated samples showed significantly less SG neurites per SG explant compared to control in both concentrations used. (e) Average length of SG neurites observed on SG explants. The lengths of neurites observed in control samples are compared to those seen with two different concentrations of rapamycin. Rapamycin-treated samples were significantly shorter in the highest rapamycin concentrations used. (f) Average area of supporting cells observed around SG explants. Rapamycin treatment resulted in significantly smaller area of supporting cells around the SG explant compared to control samples in both concentrations used. Asterisks denote statistical difference compared to control (). Data are represented as mean. Vertical lines represent one standard deviation. for each experimental condition.

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