Fig. 2.

Bottom. Glutamate and NMDA induce apoptosis in enteric neurons. Preparations of gut were exposed to glutamate or NMDA (60 min) and subsequently reincubated in culture medium for 48 hr. A, Submucosal ganglion in a control preparation. NSE (red) immunoreactivity is present in a subset of cell bodies (arrow) and nerve fibers. B–D, Exposure to glutamate induces apoptosis (arrow; green) in submucosal (B) and myenteric (C) NSE-immunoreactive neurons and in cells in the circular muscle layer (D). E, NMDA produces apoptosis in myenteric neurons (arrow). F, The effect of NMDA is blocked by AP-5. Scale bars, 30 μm.