Decreased mRNA levels of the following genes were found after PAE in differentiated NPC cultures: CDK5 regulatory subunit protein 3 (Cdk5rap3, p = .04), which governs cell cycle progression, particularly neuronal differentiation; glial derived neurotrophic factor (Gdnf, p = .004), a neurotrophic factor that promotes survival of neurons; hairy enhancer of split (Hey2, p = .01, and Heyl, p = .03), both of which are important for vascularization in the embryo during development (Fischer, Schumacher, Maier, Sendtner, & Gessler, 2004); Par-6 family cell polarity regulator beta (Pard6b, p = .004), which encodes for a protein with a PDZ domain and is involved in cell division and polarization; and pleiotropin (Ptn, p = .05), which promotes neurite outgrowth during development. PAE did not induce increased mRNA levels in any genes tested in the differentiated NPC cultures.
