Analysis of dendrites according to dendrite order.Open circles represent saline-treated (+/+);filled circles, MK-801-treated (+/+); open squares, saline-treated (−/−); and filled squares, MK-801-treated (−/−) animals. A, Average length of dendrites in each order. B, Average number of dendrites in each order. * represents significant difference between saline-treated (+/+) and all other treatment groups; † represents significant difference between saline- and MK-801-treated (−/−) groups (p < 0.05; Student-Newman–Keuls).