CHOP expression in neurons derived from primary cultured embryonic hippocampal neurons of E18 rats (400×): (a) neurons of the control group and (b) neurons under high glucose treatment; the arrows showed that the neurons of high glucose medium group (b) had numerous fragmentations and degenerated cells with shrunk neuritis and dendrite decreased while the expression of CHOP in neurons under high glucose medium (b) was apparently increased compared with the normal glucose medium (a).