GSPE protects cells against 0.1 mM [Mg2+]
-induced neurotoxicity. Phase-contrast photomicrographs showed the same field of cultured rat hippocampal neurons before treatment (left, D14) and 20-24 h after treatment (right, D15). The cells were treated with normal medium (control), GSPE (6 μg/ml), 0.1 mM [Mg2+]o and 0.1 mM [Mg2+]o plus GSPE (+ GSPE)-containing medium at 14 days in culture. Hippocampal neurons (identified by a light halo around the soma and long fine processes) grew on a bed of non-neuronal cells that formed a mosaic beneath them.