Table 1.

Development and alignment of hair cells in apical (Apex) and basal (Base) cochlear pieces maintained with or without mesenchyme

Apex Base
Conditions R2 value Number of hair cells per piece R2 value Number of hair cells per piece
In vivo (PO) 0.98 ± 0.006 ND 0.99 ± 0.004 ND
n = 3 n = 3
E13.5 + 5 DIV/−mes 0.79 ± 0.03* 99.8 ± 12.9 0.82 ± 0.02* 109 ± 12
n = 20 n = 20 n = 21 n = 21
p = 0.01 p = 0.001
E12.5 + 6 DIV/−mes ND 7 ± 1.5* 0.77 ± 0.08* 62 ± 9.8*
n = 10 n = 12 n = 12
p = 0.001 p = 0.03 p = 0.01
E12.5 + 6 DIV/+mes 0.92 ± 0.02* 169 ± 46 ND ND
n = 3 n = 3
p = 0.01
E12.5 + 6 DIV reassociated with endogenous mesenchyme ND >100 in each ND ND
n = 4
  • R2 values indicate the average overall correlation coefficient for alignment for hair cells in each condition ± SEM. The R2 values for E13.5 + 5 DIV/−mes apex and base and E12.5 + 6 DIV/−mes base all differed significantly from the R2 values for in vivo (indicated by*), and the p values for each are included in the table. Number of hair cells per piece indicates the average number of hair cells per piece for each condition ± SEM. The values for number of hair cells for apex E12.5 + 6 DIV/−mes represents the mean number of hair cells for those explants in which hair cells developed. The value for number of hair cells in E12.5 + 6 DIV/−mes differed significantly from E13.5 + 5 DIV/−mes apex and base and E12.5 + 6 DIV/−mes base and E12.5 + 6 DIV/+mes (p for all comparisons was 0.001). Number of hair cells in E12.5 + 6 DIV/−mes base was also significantly different from E13.5 + 5 DIV/−mes. ND, Not determined.